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* [PATCH v7 1/4] can: m_can: Create a m_can platform framework
@ 2019-03-05 15:52 Dan Murphy
  2019-03-05 15:52 ` [PATCH v7 2/4] can: m_can: Rename m_can_priv to m_can_classdev Dan Murphy
                   ` (3 more replies)
  0 siblings, 4 replies; 18+ messages in thread
From: Dan Murphy @ 2019-03-05 15:52 UTC (permalink / raw)
  To: wg, mkl, davem; +Cc: linux-can, netdev, linux-kernel, Dan Murphy

Create a m_can platform framework that peripherial
devices can register to and use common code and register sets.
The peripherial devices may provide read/write and configuration
support of the IP.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
---


v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/

v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/

 drivers/net/can/m_can/Kconfig          |  13 +-
 drivers/net/can/m_can/Makefile         |   1 +
 drivers/net/can/m_can/m_can.c          | 700 +++++++++++++------------
 drivers/net/can/m_can/m_can.h          | 110 ++++
 drivers/net/can/m_can/m_can_platform.c | 202 +++++++
 5 files changed, 682 insertions(+), 344 deletions(-)
 create mode 100644 drivers/net/can/m_can/m_can.h
 create mode 100644 drivers/net/can/m_can/m_can_platform.c

diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
index 04f20dd39007..f7119fd72df4 100644
--- a/drivers/net/can/m_can/Kconfig
+++ b/drivers/net/can/m_can/Kconfig
@@ -1,5 +1,14 @@
 config CAN_M_CAN
+	tristate "Bosch M_CAN support"
+	---help---
+	  Say Y here if you want support for Bosch M_CAN controller framework.
+	  This is common support for devices that embed the Bosch M_CAN IP.
+
+config CAN_M_CAN_PLATFORM
+	tristate "Bosch M_CAN support for io-mapped devices"
 	depends on HAS_IOMEM
-	tristate "Bosch M_CAN devices"
+	depends on CAN_M_CAN
 	---help---
-	  Say Y here if you want to support for Bosch M_CAN controller.
+	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
+	  This support is for devices that have the Bosch M_CAN controller
+	  IP embedded into the device and the IP is IO Mapped to the processor.
diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
index 8bbd7f24f5be..057bbcdb3c74 100644
--- a/drivers/net/can/m_can/Makefile
+++ b/drivers/net/can/m_can/Makefile
@@ -3,3 +3,4 @@
 #
 
 obj-$(CONFIG_CAN_M_CAN) += m_can.o
+obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 9b449400376b..a60278d94126 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -1,20 +1,14 @@
-/*
- * CAN bus driver for Bosch M_CAN controller
- *
- * Copyright (C) 2014 Freescale Semiconductor, Inc.
- *	Dong Aisheng <b29396@freescale.com>
- *
- * Bosch M_CAN user manual can be obtained from:
+// SPDX-License-Identifier: GPL-2.0
+// CAN bus driver for Bosch M_CAN controller
+// Copyright (C) 2014 Freescale Semiconductor, Inc.
+//      Dong Aisheng <b29396@freescale.com>
+// Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
+
+/* Bosch M_CAN user manual can be obtained from:
  * http://www.bosch-semiconductors.de/media/pdf_1/ipmodules_1/m_can/
  * mcan_users_manual_v302.pdf
- *
- * This file is licensed under the terms of the GNU General Public
- * License version 2. This program is licensed "as is" without any
- * warranty of any kind, whether express or implied.
  */
 
-#include <linux/clk.h>
-#include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
@@ -28,11 +22,7 @@
 #include <linux/can/dev.h>
 #include <linux/pinctrl/consumer.h>
 
-/* napi related */
-#define M_CAN_NAPI_WEIGHT	64
-
-/* message ram configuration data length */
-#define MRAM_CFG_LEN	8
+#include "m_can.h"
 
 /* registers definition */
 enum m_can_reg {
@@ -86,28 +76,11 @@ enum m_can_reg {
 	M_CAN_TXEFA	= 0xf8,
 };
 
-/* m_can lec values */
-enum m_can_lec_type {
-	LEC_NO_ERROR = 0,
-	LEC_STUFF_ERROR,
-	LEC_FORM_ERROR,
-	LEC_ACK_ERROR,
-	LEC_BIT1_ERROR,
-	LEC_BIT0_ERROR,
-	LEC_CRC_ERROR,
-	LEC_UNUSED,
-};
+/* napi related */
+#define M_CAN_NAPI_WEIGHT	64
 
-enum m_can_mram_cfg {
-	MRAM_SIDF = 0,
-	MRAM_XIDF,
-	MRAM_RXF0,
-	MRAM_RXF1,
-	MRAM_RXB,
-	MRAM_TXE,
-	MRAM_TXB,
-	MRAM_CFG_NUM,
-};
+/* message ram configuration data length */
+#define MRAM_CFG_LEN	8
 
 /* Core Release Register (CREL) */
 #define CREL_REL_SHIFT		28
@@ -347,68 +320,72 @@ enum m_can_mram_cfg {
 #define TX_EVENT_MM_SHIFT	TX_BUF_MM_SHIFT
 #define TX_EVENT_MM_MASK	(0xff << TX_EVENT_MM_SHIFT)
 
-/* address offset and element number for each FIFO/Buffer in the Message RAM */
-struct mram_cfg {
-	u16 off;
-	u8  num;
-};
-
-/* m_can private data structure */
-struct m_can_priv {
-	struct can_priv can;	/* must be the first member */
-	struct napi_struct napi;
-	struct net_device *dev;
-	struct device *device;
-	struct clk *hclk;
-	struct clk *cclk;
-	void __iomem *base;
-	u32 irqstatus;
-	int version;
-
-	/* message ram configuration */
-	void __iomem *mram_base;
-	struct mram_cfg mcfg[MRAM_CFG_NUM];
-};
+static u32 m_can_read(struct m_can_priv *priv, enum m_can_reg reg)
+{
+	if (priv->ops->read_reg)
+		return priv->ops->read_reg(priv, reg);
+	else
+		return -EINVAL;
+}
 
-static inline u32 m_can_read(const struct m_can_priv *priv, enum m_can_reg reg)
+static int m_can_write(struct m_can_priv *priv, enum m_can_reg reg, u32 val)
 {
-	return readl(priv->base + reg);
+	if (priv->ops->write_reg)
+		return priv->ops->write_reg(priv, reg, val);
+	else
+		return -EINVAL;
 }
 
-static inline void m_can_write(const struct m_can_priv *priv,
-			       enum m_can_reg reg, u32 val)
+static u32 m_can_fifo_read(struct m_can_priv *priv,
+			   u32 fgi, unsigned int offset)
 {
-	writel(val, priv->base + reg);
+	u32 addr_offset = priv->mcfg[MRAM_RXF0].off + fgi * RXF0_ELEMENT_SIZE +
+			  offset;
+
+	if (priv->ops->read_fifo)
+		return priv->ops->read_fifo(priv, addr_offset);
+	else
+		return -EINVAL;
 }
 
-static inline u32 m_can_fifo_read(const struct m_can_priv *priv,
-				  u32 fgi, unsigned int offset)
+static u32 m_can_fifo_write(struct m_can_priv *priv,
+			    u32 fpi, unsigned int offset, u32 val)
 {
-	return readl(priv->mram_base + priv->mcfg[MRAM_RXF0].off +
-		     fgi * RXF0_ELEMENT_SIZE + offset);
+	u32 addr_offset = priv->mcfg[MRAM_TXB].off + fpi * TXB_ELEMENT_SIZE +
+			  offset;
+
+	if (priv->ops->write_fifo)
+		return priv->ops->write_fifo(priv, addr_offset, val);
+	else
+		return -EINVAL;
 }
 
-static inline void m_can_fifo_write(const struct m_can_priv *priv,
-				    u32 fpi, unsigned int offset, u32 val)
+static u32 m_can_fifo_write_no_off(struct m_can_priv *priv,
+				   u32 fpi, u32 val)
 {
-	writel(val, priv->mram_base + priv->mcfg[MRAM_TXB].off +
-	       fpi * TXB_ELEMENT_SIZE + offset);
+	if (priv->ops->write_fifo)
+		return priv->ops->write_fifo(priv, fpi, val);
+	else
+		return 0;
 }
 
-static inline u32 m_can_txe_fifo_read(const struct m_can_priv *priv,
-				      u32 fgi,
-				      u32 offset) {
-	return readl(priv->mram_base + priv->mcfg[MRAM_TXE].off +
-			fgi * TXE_ELEMENT_SIZE + offset);
+static u32 m_can_txe_fifo_read(struct m_can_priv *priv, u32 fgi, u32 offset)
+{
+	u32 addr_offset = priv->mcfg[MRAM_TXE].off + fgi * TXE_ELEMENT_SIZE +
+			  offset;
+
+	if (priv->ops->read_fifo)
+		return priv->ops->read_fifo(priv, addr_offset);
+	else
+		return -EINVAL;
 }
 
-static inline bool m_can_tx_fifo_full(const struct m_can_priv *priv)
+static inline bool m_can_tx_fifo_full(struct m_can_priv *priv)
 {
 		return !!(m_can_read(priv, M_CAN_TXFQS) & TXFQS_TFQF);
 }
 
-static inline void m_can_config_endisable(const struct m_can_priv *priv,
-					  bool enable)
+void m_can_config_endisable(struct m_can_priv *priv, bool enable)
 {
 	u32 cccr = m_can_read(priv, M_CAN_CCCR);
 	u32 timeout = 10;
@@ -430,7 +407,7 @@ static inline void m_can_config_endisable(const struct m_can_priv *priv,
 
 	while ((m_can_read(priv, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) {
 		if (timeout == 0) {
-			netdev_warn(priv->dev, "Failed to init module\n");
+			netdev_warn(priv->net, "Failed to init module\n");
 			return;
 		}
 		timeout--;
@@ -438,13 +415,13 @@ static inline void m_can_config_endisable(const struct m_can_priv *priv,
 	}
 }
 
-static inline void m_can_enable_all_interrupts(const struct m_can_priv *priv)
+static inline void m_can_enable_all_interrupts(struct m_can_priv *priv)
 {
 	/* Only interrupt line 0 is used in this driver */
 	m_can_write(priv, M_CAN_ILE, ILE_EINT0);
 }
 
-static inline void m_can_disable_all_interrupts(const struct m_can_priv *priv)
+static inline void m_can_disable_all_interrupts(struct m_can_priv *priv)
 {
 	m_can_write(priv, M_CAN_ILE, 0x0);
 }
@@ -633,9 +610,12 @@ static int m_can_clk_start(struct m_can_priv *priv)
 {
 	int err;
 
-	err = pm_runtime_get_sync(priv->device);
+	if (priv->pm_clock_support == 0)
+		return 0;
+
+	err = pm_runtime_get_sync(priv->dev);
 	if (err < 0) {
-		pm_runtime_put_noidle(priv->device);
+		pm_runtime_put_noidle(priv->dev);
 		return err;
 	}
 
@@ -644,7 +624,8 @@ static int m_can_clk_start(struct m_can_priv *priv)
 
 static void m_can_clk_stop(struct m_can_priv *priv)
 {
-	pm_runtime_put_sync(priv->device);
+	if (priv->pm_clock_support)
+		pm_runtime_put_sync(priv->dev);
 }
 
 static int m_can_get_berr_counter(const struct net_device *dev,
@@ -811,9 +792,8 @@ static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
 	return work_done;
 }
 
-static int m_can_poll(struct napi_struct *napi, int quota)
+static int m_can_rx_handler(struct net_device *dev, int quota)
 {
-	struct net_device *dev = napi->dev;
 	struct m_can_priv *priv = netdev_priv(dev);
 	int work_done = 0;
 	u32 irqstatus, psr;
@@ -831,13 +811,33 @@ static int m_can_poll(struct napi_struct *napi, int quota)
 
 	if (irqstatus & IR_RF0N)
 		work_done += m_can_do_rx_poll(dev, (quota - work_done));
+end:
+	return work_done;
+}
+
+static int m_can_rx_peripherial(struct net_device *dev)
+{
+	struct m_can_priv *priv = netdev_priv(dev);
+
+	m_can_rx_handler(dev, 1);
+
+	m_can_enable_all_interrupts(priv);
+
+	return 0;
+}
 
+static int m_can_poll(struct napi_struct *napi, int quota)
+{
+	struct net_device *dev = napi->dev;
+	struct m_can_priv *priv = netdev_priv(dev);
+	int work_done;
+
+	work_done = m_can_rx_handler(dev, quota);
 	if (work_done < quota) {
 		napi_complete_done(napi, work_done);
 		m_can_enable_all_interrupts(priv);
 	}
 
-end:
 	return work_done;
 }
 
@@ -894,6 +894,9 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
 	if (ir & IR_ALL_INT)
 		m_can_write(priv, M_CAN_IR, ir);
 
+	if (priv->ops->clear_interrupts)
+		priv->ops->clear_interrupts(priv);
+
 	/* schedule NAPI in case of
 	 * - rx IRQ
 	 * - state change IRQ
@@ -902,7 +905,10 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
 	if ((ir & IR_RF0N) || (ir & IR_ERR_ALL_30X)) {
 		priv->irqstatus = ir;
 		m_can_disable_all_interrupts(priv);
-		napi_schedule(&priv->napi);
+		if (!priv->is_peripherial)
+			napi_schedule(&priv->napi);
+		else
+			m_can_rx_peripherial(dev);
 	}
 
 	if (priv->version == 30) {
@@ -1155,6 +1161,9 @@ static void m_can_chip_config(struct net_device *dev)
 	m_can_set_bittiming(dev);
 
 	m_can_config_endisable(priv, false);
+
+	if (priv->ops->init)
+		priv->ops->init(priv);
 }
 
 static void m_can_start(struct net_device *dev)
@@ -1188,20 +1197,17 @@ static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
  * else it returns the release and step coded as:
  * return value = 10 * <release> + 1 * <step>
  */
-static int m_can_check_core_release(void __iomem *m_can_base)
+static int m_can_check_core_release(struct m_can_priv *priv)
 {
 	u32 crel_reg;
 	u8 rel;
 	u8 step;
 	int res;
-	struct m_can_priv temp_priv = {
-		.base = m_can_base
-	};
 
 	/* Read Core Release Version and split into version number
 	 * Example: Version 3.2.1 => rel = 3; step = 2; substep = 1;
 	 */
-	crel_reg = m_can_read(&temp_priv, M_CAN_CREL);
+	crel_reg = m_can_read(priv, M_CAN_CREL);
 	rel = (u8)((crel_reg & CREL_REL_MASK) >> CREL_REL_SHIFT);
 	step = (u8)((crel_reg & CREL_STEP_MASK) >> CREL_STEP_SHIFT);
 
@@ -1219,18 +1225,26 @@ static int m_can_check_core_release(void __iomem *m_can_base)
 /* Selectable Non ISO support only in version 3.2.x
  * This function checks if the bit is writable.
  */
-static bool m_can_niso_supported(const struct m_can_priv *priv)
+static bool m_can_niso_supported(struct m_can_priv *priv)
 {
-	u32 cccr_reg, cccr_poll;
-	int niso_timeout;
+	u32 cccr_reg, cccr_poll = 0;
+	int niso_timeout = -ETIMEDOUT;
+	int i;
 
 	m_can_config_endisable(priv, true);
 	cccr_reg = m_can_read(priv, M_CAN_CCCR);
 	cccr_reg |= CCCR_NISO;
 	m_can_write(priv, M_CAN_CCCR, cccr_reg);
 
-	niso_timeout = readl_poll_timeout((priv->base + M_CAN_CCCR), cccr_poll,
-					  (cccr_poll == cccr_reg), 0, 10);
+	for (i = 0; i <= 10; i++) {
+		cccr_poll = m_can_read(priv, M_CAN_CCCR);
+		if (cccr_poll == cccr_reg) {
+			niso_timeout = 0;
+			break;
+		}
+
+		usleep_range(1, 5);
+	}
 
 	/* Clear NISO */
 	cccr_reg &= ~(CCCR_NISO);
@@ -1242,107 +1256,79 @@ static bool m_can_niso_supported(const struct m_can_priv *priv)
 	return !niso_timeout;
 }
 
-static int m_can_dev_setup(struct platform_device *pdev, struct net_device *dev,
-			   void __iomem *addr)
+static int m_can_dev_setup(struct m_can_priv *m_can_dev)
 {
-	struct m_can_priv *priv;
+	struct net_device *dev = m_can_dev->net;
 	int m_can_version;
 
-	m_can_version = m_can_check_core_release(addr);
+	m_can_version = m_can_check_core_release(m_can_dev);
 	/* return if unsupported version */
 	if (!m_can_version) {
-		dev_err(&pdev->dev, "Unsupported version number: %2d",
+		dev_err(m_can_dev->dev, "Unsupported version number: %2d",
 			m_can_version);
 		return -EINVAL;
 	}
 
-	priv = netdev_priv(dev);
-	netif_napi_add(dev, &priv->napi, m_can_poll, M_CAN_NAPI_WEIGHT);
+	if (!m_can_dev->is_peripherial)
+		netif_napi_add(dev, &m_can_dev->napi,
+			       m_can_poll, M_CAN_NAPI_WEIGHT);
 
 	/* Shared properties of all M_CAN versions */
-	priv->version = m_can_version;
-	priv->dev = dev;
-	priv->base = addr;
-	priv->can.do_set_mode = m_can_set_mode;
-	priv->can.do_get_berr_counter = m_can_get_berr_counter;
+	m_can_dev->version = m_can_version;
+	m_can_dev->can.do_set_mode = m_can_set_mode;
+	m_can_dev->can.do_get_berr_counter = m_can_get_berr_counter;
 
 	/* Set M_CAN supported operations */
-	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
+	m_can_dev->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 					CAN_CTRLMODE_LISTENONLY |
 					CAN_CTRLMODE_BERR_REPORTING |
 					CAN_CTRLMODE_FD;
 
 	/* Set properties depending on M_CAN version */
-	switch (priv->version) {
+	switch (m_can_dev->version) {
 	case 30:
 		/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */
 		can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
-		priv->can.bittiming_const = &m_can_bittiming_const_30X;
-		priv->can.data_bittiming_const =
-				&m_can_data_bittiming_const_30X;
+		m_can_dev->can.bittiming_const = m_can_dev->bit_timing ?
+			m_can_dev->bit_timing : &m_can_bittiming_const_30X;
+
+		m_can_dev->can.data_bittiming_const = m_can_dev->data_timing ?
+						m_can_dev->data_timing :
+						&m_can_data_bittiming_const_30X;
 		break;
 	case 31:
 		/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */
 		can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
-		priv->can.bittiming_const = &m_can_bittiming_const_31X;
-		priv->can.data_bittiming_const =
-				&m_can_data_bittiming_const_31X;
+		m_can_dev->can.bittiming_const = m_can_dev->bit_timing ?
+			m_can_dev->bit_timing : &m_can_bittiming_const_31X;
+
+		m_can_dev->can.data_bittiming_const = m_can_dev->data_timing ?
+						m_can_dev->data_timing :
+						&m_can_data_bittiming_const_31X;
 		break;
 	case 32:
-		priv->can.bittiming_const = &m_can_bittiming_const_31X;
-		priv->can.data_bittiming_const =
-				&m_can_data_bittiming_const_31X;
-		priv->can.ctrlmode_supported |= (m_can_niso_supported(priv)
+		m_can_dev->can.bittiming_const = m_can_dev->bit_timing ?
+			m_can_dev->bit_timing : &m_can_bittiming_const_31X;
+
+		m_can_dev->can.data_bittiming_const = m_can_dev->data_timing ?
+						m_can_dev->data_timing :
+						&m_can_data_bittiming_const_31X;
+
+		m_can_dev->can.ctrlmode_supported |=
+						(m_can_niso_supported(m_can_dev)
 						? CAN_CTRLMODE_FD_NON_ISO
 						: 0);
 		break;
 	default:
-		dev_err(&pdev->dev, "Unsupported version number: %2d",
-			priv->version);
+		dev_err(m_can_dev->dev, "Unsupported version number: %2d",
+			m_can_dev->version);
 		return -EINVAL;
 	}
 
-	return 0;
-}
-
-static int m_can_open(struct net_device *dev)
-{
-	struct m_can_priv *priv = netdev_priv(dev);
-	int err;
-
-	err = m_can_clk_start(priv);
-	if (err)
-		return err;
-
-	/* open the can device */
-	err = open_candev(dev);
-	if (err) {
-		netdev_err(dev, "failed to open can device\n");
-		goto exit_disable_clks;
-	}
-
-	/* register interrupt handler */
-	err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name,
-			  dev);
-	if (err < 0) {
-		netdev_err(dev, "failed to request interrupt\n");
-		goto exit_irq_fail;
-	}
-
-	/* start the m_can controller */
-	m_can_start(dev);
-
-	can_led_event(dev, CAN_LED_EVENT_OPEN);
-	napi_enable(&priv->napi);
-	netif_start_queue(dev);
+	if (m_can_dev->ops->init)
+		m_can_dev->ops->init(m_can_dev);
 
 	return 0;
-
-exit_irq_fail:
-	close_candev(dev);
-exit_disable_clks:
-	m_can_clk_stop(priv);
-	return err;
 }
 
 static void m_can_stop(struct net_device *dev)
@@ -1361,10 +1347,18 @@ static int m_can_close(struct net_device *dev)
 	struct m_can_priv *priv = netdev_priv(dev);
 
 	netif_stop_queue(dev);
-	napi_disable(&priv->napi);
+	if (!priv->is_peripherial)
+		napi_disable(&priv->napi);
 	m_can_stop(dev);
 	m_can_clk_stop(priv);
 	free_irq(dev->irq, dev);
+
+	if (priv->is_peripherial) {
+		priv->tx_skb = NULL;
+		destroy_workqueue(priv->tx_wq);
+		priv->tx_wq = NULL;
+	}
+
 	close_candev(dev);
 	can_led_event(dev, CAN_LED_EVENT_STOP);
 
@@ -1385,18 +1379,15 @@ static int m_can_next_echo_skb_occupied(struct net_device *dev, int putidx)
 	return !!priv->can.echo_skb[next_idx];
 }
 
-static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
-				    struct net_device *dev)
+static netdev_tx_t m_can_tx_handler(struct m_can_priv *priv)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
-	struct canfd_frame *cf = (struct canfd_frame *)skb->data;
+	struct canfd_frame *cf = (struct canfd_frame *)priv->tx_skb->data;
+	struct net_device *dev = priv->net;
+	struct sk_buff *skb = priv->tx_skb;
 	u32 id, cccr, fdflags;
 	int i;
 	int putidx;
 
-	if (can_dropped_invalid_skb(dev, skb))
-		return NETDEV_TX_OK;
-
 	/* Generate ID field for TX buffer Element */
 	/* Common to all supported M_CAN versions */
 	if (cf->can_id & CAN_EFF_FLAG) {
@@ -1492,14 +1483,113 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
 		m_can_write(priv, M_CAN_TXBAR, (1 << putidx));
 
 		/* stop network queue if fifo full */
-			if (m_can_tx_fifo_full(priv) ||
-			    m_can_next_echo_skb_occupied(dev, putidx))
-				netif_stop_queue(dev);
+		if (m_can_tx_fifo_full(priv) ||
+		    m_can_next_echo_skb_occupied(dev, putidx))
+			netif_stop_queue(dev);
+	}
+
+	return NETDEV_TX_OK;
+}
+
+static void m_can_tx_work_queue(struct work_struct *ws)
+{
+	struct m_can_priv *priv = container_of(ws, struct m_can_priv,
+						tx_work);
+	netdev_tx_t ret;
+
+	ret = m_can_tx_handler(priv);
+	if (ret == NETDEV_TX_OK)
+		priv->tx_skb = NULL;
+}
+
+static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
+				    struct net_device *dev)
+{
+	struct m_can_priv *priv = netdev_priv(dev);
+
+	if (can_dropped_invalid_skb(dev, skb))
+		return NETDEV_TX_OK;
+
+	if (priv->is_peripherial) {
+		if (priv->tx_skb) {
+			netdev_err(dev, "hard_xmit called while tx busy\n");
+			return NETDEV_TX_BUSY;
+		}
+
+		priv->tx_skb = skb;
+		netif_stop_queue(priv->net);
+		queue_work(priv->tx_wq, &priv->tx_work);
+	} else {
+		priv->tx_skb = skb;
+		return m_can_tx_handler(priv);
 	}
 
 	return NETDEV_TX_OK;
 }
 
+static int m_can_open(struct net_device *dev)
+{
+	struct m_can_priv *priv = netdev_priv(dev);
+	int err;
+
+	err = m_can_clk_start(priv);
+	if (err)
+		return err;
+
+	/* open the can device */
+	err = open_candev(dev);
+	if (err) {
+		netdev_err(dev, "failed to open can device\n");
+		goto exit_disable_clks;
+	}
+
+	/* register interrupt handler */
+	if (priv->is_peripherial) {
+		priv->tx_skb = NULL;
+		priv->tx_wq = alloc_workqueue("mcan_wq",
+					      WQ_FREEZABLE | WQ_MEM_RECLAIM, 0);
+		if (!priv->tx_wq) {
+			err = -ENOMEM;
+			goto out_wq_fail;
+		}
+
+		INIT_WORK(&priv->tx_work, m_can_tx_work_queue);
+
+		err = request_threaded_irq(dev->irq, NULL, m_can_isr,
+					   IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
+					   dev->name, dev);
+	} else {
+		err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name,
+				  dev);
+	}
+
+	if (err < 0) {
+		netdev_err(dev, "failed to request interrupt\n");
+		goto exit_irq_fail;
+	}
+
+	/* start the m_can controller */
+	m_can_start(dev);
+
+	can_led_event(dev, CAN_LED_EVENT_OPEN);
+
+	if (!priv->is_peripherial)
+		napi_enable(&priv->napi);
+
+	netif_start_queue(dev);
+
+	return 0;
+
+exit_irq_fail:
+	if (priv->is_peripherial)
+		destroy_workqueue(priv->tx_wq);
+out_wq_fail:
+	close_candev(dev);
+exit_disable_clks:
+	m_can_clk_stop(priv);
+	return err;
+}
+
 static const struct net_device_ops m_can_netdev_ops = {
 	.ndo_open = m_can_open,
 	.ndo_stop = m_can_close,
@@ -1515,20 +1605,6 @@ static int register_m_can_dev(struct net_device *dev)
 	return register_candev(dev);
 }
 
-static void m_can_init_ram(struct m_can_priv *priv)
-{
-	int end, i, start;
-
-	/* initialize the entire Message RAM in use to avoid possible
-	 * ECC/parity checksum errors when reading an uninitialized buffer
-	 */
-	start = priv->mcfg[MRAM_SIDF].off;
-	end = priv->mcfg[MRAM_TXB].off +
-		priv->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
-	for (i = start; i < end; i += 4)
-		writel(0x0, priv->mram_base + i);
-}
-
 static void m_can_of_parse_mram(struct m_can_priv *priv,
 				const u32 *mram_config_vals)
 {
@@ -1556,9 +1632,8 @@ static void m_can_of_parse_mram(struct m_can_priv *priv,
 	priv->mcfg[MRAM_TXB].num = mram_config_vals[7] &
 			(TXBC_NDTB_MASK >> TXBC_NDTB_SHIFT);
 
-	dev_dbg(priv->device,
-		"mram_base %p sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",
-		priv->mram_base,
+	dev_dbg(priv->dev,
+		"sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",
 		priv->mcfg[MRAM_SIDF].off, priv->mcfg[MRAM_SIDF].num,
 		priv->mcfg[MRAM_XIDF].off, priv->mcfg[MRAM_XIDF].num,
 		priv->mcfg[MRAM_RXF0].off, priv->mcfg[MRAM_RXF0].num,
@@ -1566,63 +1641,55 @@ static void m_can_of_parse_mram(struct m_can_priv *priv,
 		priv->mcfg[MRAM_RXB].off, priv->mcfg[MRAM_RXB].num,
 		priv->mcfg[MRAM_TXE].off, priv->mcfg[MRAM_TXE].num,
 		priv->mcfg[MRAM_TXB].off, priv->mcfg[MRAM_TXB].num);
-
-	m_can_init_ram(priv);
 }
 
-static int m_can_plat_probe(struct platform_device *pdev)
+void m_can_init_ram(struct m_can_priv *priv)
 {
-	struct net_device *dev;
-	struct m_can_priv *priv;
-	struct resource *res;
-	void __iomem *addr;
-	void __iomem *mram_addr;
-	struct clk *hclk, *cclk;
-	int irq, ret;
-	struct device_node *np;
-	u32 mram_config_vals[MRAM_CFG_LEN];
-	u32 tx_fifo_size;
-
-	np = pdev->dev.of_node;
+	int end, i, start;
 
-	hclk = devm_clk_get(&pdev->dev, "hclk");
-	cclk = devm_clk_get(&pdev->dev, "cclk");
+	/* initialize the entire Message RAM in use to avoid possible
+	 * ECC/parity checksum errors when reading an uninitialized buffer
+	 */
+	start = priv->mcfg[MRAM_SIDF].off;
+	end = priv->mcfg[MRAM_TXB].off +
+		priv->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
 
-	if (IS_ERR(hclk) || IS_ERR(cclk)) {
-		dev_err(&pdev->dev, "no clock found\n");
-		ret = -ENODEV;
-		goto failed_ret;
-	}
+	for (i = start; i < end; i += 4)
+		m_can_fifo_write_no_off(priv, i, 0x0);
+}
+EXPORT_SYMBOL_GPL(m_can_init_ram);
 
-	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can");
-	addr = devm_ioremap_resource(&pdev->dev, res);
-	irq = platform_get_irq_byname(pdev, "int0");
+int m_can_class_get_clocks(struct m_can_priv *m_can_dev)
+{
+	int ret = 0;
 
-	if (IS_ERR(addr) || irq < 0) {
-		ret = -EINVAL;
-		goto failed_ret;
-	}
+	m_can_dev->hclk = devm_clk_get(m_can_dev->dev, "hclk");
+	m_can_dev->cclk = devm_clk_get(m_can_dev->dev, "cclk");
 
-	/* message ram could be shared */
-	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
-	if (!res) {
+	if (IS_ERR(m_can_dev->cclk)) {
+		dev_err(m_can_dev->dev, "no clock found\n");
 		ret = -ENODEV;
-		goto failed_ret;
 	}
 
-	mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
-	if (!mram_addr) {
-		ret = -ENOMEM;
-		goto failed_ret;
-	}
+	return ret;
+}
+EXPORT_SYMBOL_GPL(m_can_class_get_clocks);
 
-	/* get message ram configuration */
-	ret = of_property_read_u32_array(np, "bosch,mram-cfg",
-					 mram_config_vals,
-					 sizeof(mram_config_vals) / 4);
+struct m_can_priv *m_can_class_allocate_dev(struct device *dev)
+{
+	struct m_can_priv *class_dev = NULL;
+	u32 mram_config_vals[MRAM_CFG_LEN];
+	struct net_device *net_dev;
+	u32 tx_fifo_size;
+	int ret;
+
+	ret = fwnode_property_read_u32_array(dev_fwnode(dev),
+					     "bosch,mram-cfg",
+					     mram_config_vals,
+					     sizeof(mram_config_vals) / 4);
 	if (ret) {
-		dev_err(&pdev->dev, "Could not get Message RAM configuration.");
-		goto failed_ret;
+		dev_err(dev, "Could not get Message RAM configuration.");
+		goto out;
 	}
 
 	/* Get TX FIFO size
@@ -1631,66 +1698,74 @@ static int m_can_plat_probe(struct platform_device *pdev)
 	tx_fifo_size = mram_config_vals[7];
 
 	/* allocate the m_can device */
-	dev = alloc_candev(sizeof(*priv), tx_fifo_size);
-	if (!dev) {
-		ret = -ENOMEM;
-		goto failed_ret;
+	net_dev = alloc_candev(sizeof(*class_dev), tx_fifo_size);
+	if (!net_dev) {
+		dev_err(dev, "Failed to allocate CAN device");
+		goto out;
 	}
 
-	priv = netdev_priv(dev);
-	dev->irq = irq;
-	priv->device = &pdev->dev;
-	priv->hclk = hclk;
-	priv->cclk = cclk;
-	priv->can.clock.freq = clk_get_rate(cclk);
-	priv->mram_base = mram_addr;
+	class_dev = netdev_priv(net_dev);
+	if (!class_dev) {
+		dev_err(dev, "Failed to init netdev private");
+		goto out;
+	}
 
-	platform_set_drvdata(pdev, dev);
-	SET_NETDEV_DEV(dev, &pdev->dev);
+	class_dev->net = net_dev;
+	class_dev->dev = dev;
+	SET_NETDEV_DEV(net_dev, dev);
 
-	/* Enable clocks. Necessary to read Core Release in order to determine
-	 * M_CAN version
-	 */
-	pm_runtime_enable(&pdev->dev);
-	ret = m_can_clk_start(priv);
-	if (ret)
-		goto pm_runtime_fail;
+	m_can_of_parse_mram(class_dev, mram_config_vals);
+out:
+	return class_dev;
+}
+EXPORT_SYMBOL_GPL(m_can_class_allocate_dev);
+
+int m_can_class_register(struct m_can_priv *m_can_dev)
+{
+	int ret;
 
-	ret = m_can_dev_setup(pdev, dev, addr);
+	if (m_can_dev->pm_clock_support) {
+		pm_runtime_enable(m_can_dev->dev);
+		ret = m_can_clk_start(m_can_dev);
+		if (ret)
+			goto pm_runtime_fail;
+	}
+
+	ret = m_can_dev_setup(m_can_dev);
 	if (ret)
 		goto clk_disable;
 
-	ret = register_m_can_dev(dev);
+	ret = register_m_can_dev(m_can_dev->net);
 	if (ret) {
-		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
-			KBUILD_MODNAME, ret);
+		dev_err(m_can_dev->dev, "registering %s failed (err=%d)\n",
+			m_can_dev->net->name, ret);
 		goto clk_disable;
 	}
 
-	m_can_of_parse_mram(priv, mram_config_vals);
-
-	devm_can_led_init(dev);
+	devm_can_led_init(m_can_dev->net);
 
-	of_can_transceiver(dev);
+	of_can_transceiver(m_can_dev->net);
 
-	dev_info(&pdev->dev, "%s device registered (irq=%d, version=%d)\n",
-		 KBUILD_MODNAME, dev->irq, priv->version);
+	dev_info(m_can_dev->dev, "%s device registered (irq=%d, version=%d)\n",
+		 KBUILD_MODNAME, m_can_dev->net->irq, m_can_dev->version);
 
 	/* Probe finished
 	 * Stop clocks. They will be reactivated once the M_CAN device is opened
 	 */
 clk_disable:
-	m_can_clk_stop(priv);
+	m_can_clk_stop(m_can_dev);
 pm_runtime_fail:
 	if (ret) {
-		pm_runtime_disable(&pdev->dev);
-		free_candev(dev);
+		if (m_can_dev->pm_clock_support)
+			pm_runtime_disable(m_can_dev->dev);
+		free_candev(m_can_dev->net);
 	}
-failed_ret:
+
 	return ret;
 }
+EXPORT_SYMBOL_GPL(m_can_class_register);
 
-static __maybe_unused int m_can_suspend(struct device *dev)
+int m_can_class_suspend(struct device *dev)
 {
 	struct net_device *ndev = dev_get_drvdata(dev);
 	struct m_can_priv *priv = netdev_priv(ndev);
@@ -1708,8 +1783,9 @@ static __maybe_unused int m_can_suspend(struct device *dev)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(m_can_class_suspend);
 
-static __maybe_unused int m_can_resume(struct device *dev)
+int m_can_class_resume(struct device *dev)
 {
 	struct net_device *ndev = dev_get_drvdata(dev);
 	struct m_can_priv *priv = netdev_priv(ndev);
@@ -1733,79 +1809,19 @@ static __maybe_unused int m_can_resume(struct device *dev)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(m_can_class_resume);
 
-static void unregister_m_can_dev(struct net_device *dev)
+void m_can_class_unregister(struct m_can_priv *m_can_dev)
 {
-	unregister_candev(dev);
-}
+	unregister_candev(m_can_dev->net);
 
-static int m_can_plat_remove(struct platform_device *pdev)
-{
-	struct net_device *dev = platform_get_drvdata(pdev);
+	m_can_clk_stop(m_can_dev);
 
-	unregister_m_can_dev(dev);
-
-	pm_runtime_disable(&pdev->dev);
-
-	platform_set_drvdata(pdev, NULL);
-
-	free_candev(dev);
-
-	return 0;
-}
-
-static int __maybe_unused m_can_runtime_suspend(struct device *dev)
-{
-	struct net_device *ndev = dev_get_drvdata(dev);
-	struct m_can_priv *priv = netdev_priv(ndev);
-
-	clk_disable_unprepare(priv->cclk);
-	clk_disable_unprepare(priv->hclk);
-
-	return 0;
-}
-
-static int __maybe_unused m_can_runtime_resume(struct device *dev)
-{
-	struct net_device *ndev = dev_get_drvdata(dev);
-	struct m_can_priv *priv = netdev_priv(ndev);
-	int err;
-
-	err = clk_prepare_enable(priv->hclk);
-	if (err)
-		return err;
-
-	err = clk_prepare_enable(priv->cclk);
-	if (err)
-		clk_disable_unprepare(priv->hclk);
-
-	return err;
+	free_candev(m_can_dev->net);
 }
-
-static const struct dev_pm_ops m_can_pmops = {
-	SET_RUNTIME_PM_OPS(m_can_runtime_suspend,
-			   m_can_runtime_resume, NULL)
-	SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume)
-};
-
-static const struct of_device_id m_can_of_table[] = {
-	{ .compatible = "bosch,m_can", .data = NULL },
-	{ /* sentinel */ },
-};
-MODULE_DEVICE_TABLE(of, m_can_of_table);
-
-static struct platform_driver m_can_plat_driver = {
-	.driver = {
-		.name = KBUILD_MODNAME,
-		.of_match_table = m_can_of_table,
-		.pm     = &m_can_pmops,
-	},
-	.probe = m_can_plat_probe,
-	.remove = m_can_plat_remove,
-};
-
-module_platform_driver(m_can_plat_driver);
+EXPORT_SYMBOL_GPL(m_can_class_unregister);
 
 MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
+MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller");
diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h
new file mode 100644
index 000000000000..b60f27dd9f33
--- /dev/null
+++ b/drivers/net/can/m_can/m_can.h
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* CAN bus driver for Bosch M_CAN controller
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ */
+
+#ifndef _CAN_M_CAN_H_
+#define _CAN_M_CAN_H_
+
+#include <linux/can/core.h>
+#include <linux/can/led.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/freezer.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/iopoll.h>
+#include <linux/can/dev.h>
+#include <linux/pinctrl/consumer.h>
+
+/* m_can lec values */
+enum m_can_lec_type {
+	LEC_NO_ERROR = 0,
+	LEC_STUFF_ERROR,
+	LEC_FORM_ERROR,
+	LEC_ACK_ERROR,
+	LEC_BIT1_ERROR,
+	LEC_BIT0_ERROR,
+	LEC_CRC_ERROR,
+	LEC_UNUSED,
+};
+
+enum m_can_mram_cfg {
+	MRAM_SIDF = 0,
+	MRAM_XIDF,
+	MRAM_RXF0,
+	MRAM_RXF1,
+	MRAM_RXB,
+	MRAM_TXE,
+	MRAM_TXB,
+	MRAM_CFG_NUM,
+};
+
+/* address offset and element number for each FIFO/Buffer in the Message RAM */
+struct mram_cfg {
+	u16 off;
+	u8  num;
+};
+
+struct m_can_priv;
+struct m_can_ops {
+	/* Device specific call backs */
+	int (*clear_interrupts)(struct m_can_priv *m_can_class);
+	u32 (*read_reg)(struct m_can_priv *m_can_class, int reg);
+	int (*write_reg)(struct m_can_priv *m_can_class, int reg, int val);
+	u32 (*read_fifo)(struct m_can_priv *m_can_class, int addr_offset);
+	int (*write_fifo)(struct m_can_priv *m_can_class, int addr_offset,
+			  int val);
+	int (*init)(struct m_can_priv *m_can_class);
+};
+
+struct m_can_priv {
+	struct can_priv can;
+	struct napi_struct napi;
+	struct net_device *net;
+	struct device *dev;
+	struct clk *hclk;
+	struct clk *cclk;
+
+	struct workqueue_struct *tx_wq;
+	struct work_struct tx_work;
+	struct sk_buff *tx_skb;
+
+	struct can_bittiming_const *bit_timing;
+	struct can_bittiming_const *data_timing;
+
+	struct m_can_ops *ops;
+
+	void *device_data;
+
+	int version;
+	int freq;
+	u32 irqstatus;
+
+	int pm_clock_support;
+	int is_peripherial;
+
+	struct mram_cfg mcfg[MRAM_CFG_NUM];
+};
+
+struct m_can_priv *m_can_class_allocate_dev(struct device *dev);
+int m_can_class_register(struct m_can_priv *m_can_dev);
+void m_can_class_unregister(struct m_can_priv *m_can_dev);
+int m_can_class_get_clocks(struct m_can_priv *m_can_dev);
+void m_can_init_ram(struct m_can_priv *priv);
+void m_can_config_endisable(struct m_can_priv *priv, bool enable);
+
+int m_can_class_suspend(struct device *dev);
+int m_can_class_resume(struct device *dev);
+#endif	/* _CAN_M_H_ */
diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
new file mode 100644
index 000000000000..b02d49f9ee4c
--- /dev/null
+++ b/drivers/net/can/m_can/m_can_platform.c
@@ -0,0 +1,202 @@
+// SPDX-License-Identifier: GPL-2.0
+// IOMapped CAN bus driver for Bosch M_CAN controller
+// Copyright (C) 2014 Freescale Semiconductor, Inc.
+//	Dong Aisheng <b29396@freescale.com>
+//
+// Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
+
+#include <linux/platform_device.h>
+
+#include "m_can.h"
+
+struct m_can_plat_priv {
+	void __iomem *base;
+	void __iomem *mram_base;
+};
+
+static u32 iomap_read_reg(struct m_can_priv *cdev, int reg)
+{
+	struct m_can_plat_priv *priv =
+			(struct m_can_plat_priv *)cdev->device_data;
+
+	return readl(priv->base + reg);
+}
+
+static u32 iomap_read_fifo(struct m_can_priv *cdev, int offset)
+{
+	struct m_can_plat_priv *priv =
+			(struct m_can_plat_priv *)cdev->device_data;
+
+	return readl(priv->mram_base + offset);
+}
+
+static int iomap_write_reg(struct m_can_priv *cdev, int reg, int val)
+{
+	struct m_can_plat_priv *priv =
+			(struct m_can_plat_priv *)cdev->device_data;
+
+	writel(val, priv->base + reg);
+
+	return 0;
+}
+
+static int iomap_write_fifo(struct m_can_priv *cdev, int offset, int val)
+{
+	struct m_can_plat_priv *priv =
+			(struct m_can_plat_priv *)cdev->device_data;
+
+	writel(val, priv->mram_base + offset);
+
+	return 0;
+}
+
+static struct m_can_ops m_can_plat_ops = {
+	.read_reg = iomap_read_reg,
+	.write_reg = iomap_write_reg,
+	.write_fifo = iomap_write_fifo,
+	.read_fifo = iomap_read_fifo,
+};
+
+static int m_can_plat_probe(struct platform_device *pdev)
+{
+	struct m_can_priv *mcan_class;
+	struct m_can_plat_priv *priv;
+	struct resource *res;
+	void __iomem *addr;
+	void __iomem *mram_addr;
+	int irq, ret = 0;
+
+	mcan_class = m_can_class_allocate_dev(&pdev->dev);
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	mcan_class->device_data = priv;
+
+	m_can_class_get_clocks(mcan_class);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can");
+	addr = devm_ioremap_resource(&pdev->dev, res);
+	irq = platform_get_irq_byname(pdev, "int0");
+	if (IS_ERR(addr) || irq < 0) {
+		ret = -EINVAL;
+		goto failed_ret;
+	}
+
+	/* message ram could be shared */
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
+	if (!res) {
+		ret = -ENODEV;
+		goto failed_ret;
+	}
+
+	mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+	if (!mram_addr) {
+		ret = -ENOMEM;
+		goto failed_ret;
+	}
+
+	priv->base = addr;
+	priv->mram_base = mram_addr;
+
+	mcan_class->net->irq = irq;
+	mcan_class->pm_clock_support = 1;
+	mcan_class->can.clock.freq = clk_get_rate(mcan_class->cclk);
+	mcan_class->dev = &pdev->dev;
+
+	mcan_class->ops = &m_can_plat_ops;
+
+	mcan_class->is_peripherial = false;
+
+	platform_set_drvdata(pdev, mcan_class->dev);
+
+	m_can_init_ram(mcan_class);
+
+	ret = m_can_class_register(mcan_class);
+
+failed_ret:
+	return ret;
+}
+
+static __maybe_unused int m_can_suspend(struct device *dev)
+{
+	return m_can_class_suspend(dev);
+}
+
+static __maybe_unused int m_can_resume(struct device *dev)
+{
+	return m_can_class_resume(dev);
+}
+
+static int m_can_plat_remove(struct platform_device *pdev)
+{
+	struct net_device *dev = platform_get_drvdata(pdev);
+	struct m_can_priv *mcan_class = netdev_priv(dev);
+
+	m_can_class_unregister(mcan_class);
+
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static int __maybe_unused m_can_runtime_suspend(struct device *dev)
+{
+	struct net_device *ndev = dev_get_drvdata(dev);
+	struct m_can_priv *mcan_class = netdev_priv(ndev);
+
+	m_can_class_suspend(dev);
+
+	clk_disable_unprepare(mcan_class->cclk);
+	clk_disable_unprepare(mcan_class->hclk);
+
+	return 0;
+}
+
+static int __maybe_unused m_can_runtime_resume(struct device *dev)
+{
+	struct net_device *ndev = dev_get_drvdata(dev);
+	struct m_can_priv *mcan_class = netdev_priv(ndev);
+	int err;
+
+	err = clk_prepare_enable(mcan_class->hclk);
+	if (err)
+		return err;
+
+	err = clk_prepare_enable(mcan_class->cclk);
+	if (err)
+		clk_disable_unprepare(mcan_class->hclk);
+
+	m_can_class_resume(dev);
+
+	return err;
+}
+
+static const struct dev_pm_ops m_can_pmops = {
+	SET_RUNTIME_PM_OPS(m_can_runtime_suspend,
+			   m_can_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume)
+};
+
+static const struct of_device_id m_can_of_table[] = {
+	{ .compatible = "bosch,m_can", .data = NULL },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, m_can_of_table);
+
+static struct platform_driver m_can_plat_driver = {
+	.driver = {
+		.name = KBUILD_MODNAME,
+		.of_match_table = m_can_of_table,
+		.pm     = &m_can_pmops,
+	},
+	.probe = m_can_plat_probe,
+	.remove = m_can_plat_remove,
+};
+
+module_platform_driver(m_can_plat_driver);
+
+MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
+MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("M_CAN driver for IO Mapped Bosch controllers");
-- 
2.20.1.390.gb5101f9297


^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v7 2/4] can: m_can: Rename m_can_priv to m_can_classdev
  2019-03-05 15:52 [PATCH v7 1/4] can: m_can: Create a m_can platform framework Dan Murphy
@ 2019-03-05 15:52 ` Dan Murphy
  2019-03-08 10:25   ` Wolfgang Grandegger
  2019-03-05 15:52 ` [PATCH v7 3/4] dt-bindings: can: tcan4x5x: Add DT bindings for TCAN4x5X driver Dan Murphy
                   ` (2 subsequent siblings)
  3 siblings, 1 reply; 18+ messages in thread
From: Dan Murphy @ 2019-03-05 15:52 UTC (permalink / raw)
  To: wg, mkl, davem; +Cc: linux-can, netdev, linux-kernel, Dan Murphy

Rename the common m_can_priv class structure to
m_can_classdev as this is more descriptive.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
---

v7 - Fixed remaining checkpatch issues, renamed priv to cdev - https://lore.kernel.org/patchwork/patch/1047219/

v6 - No changes only rebase changes possibly can squash into the first patch - 
https://lore.kernel.org/patchwork/patch/1042444/

 drivers/net/can/m_can/m_can.c          | 524 ++++++++++++-------------
 drivers/net/can/m_can/m_can.h          |  28 +-
 drivers/net/can/m_can/m_can_platform.c |  16 +-
 3 files changed, 284 insertions(+), 284 deletions(-)

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index a60278d94126..6666356afc7a 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -320,94 +320,94 @@ enum m_can_reg {
 #define TX_EVENT_MM_SHIFT	TX_BUF_MM_SHIFT
 #define TX_EVENT_MM_MASK	(0xff << TX_EVENT_MM_SHIFT)
 
-static u32 m_can_read(struct m_can_priv *priv, enum m_can_reg reg)
+static u32 m_can_read(struct m_can_classdev *cdev, enum m_can_reg reg)
 {
-	if (priv->ops->read_reg)
-		return priv->ops->read_reg(priv, reg);
+	if (cdev->ops->read_reg)
+		return cdev->ops->read_reg(cdev, reg);
 	else
 		return -EINVAL;
 }
 
-static int m_can_write(struct m_can_priv *priv, enum m_can_reg reg, u32 val)
+static int m_can_write(struct m_can_classdev *cdev, enum m_can_reg reg, u32 val)
 {
-	if (priv->ops->write_reg)
-		return priv->ops->write_reg(priv, reg, val);
+	if (cdev->ops->write_reg)
+		return cdev->ops->write_reg(cdev, reg, val);
 	else
 		return -EINVAL;
 }
 
-static u32 m_can_fifo_read(struct m_can_priv *priv,
+static u32 m_can_fifo_read(struct m_can_classdev *cdev,
 			   u32 fgi, unsigned int offset)
 {
-	u32 addr_offset = priv->mcfg[MRAM_RXF0].off + fgi * RXF0_ELEMENT_SIZE +
+	u32 addr_offset = cdev->mcfg[MRAM_RXF0].off + fgi * RXF0_ELEMENT_SIZE +
 			  offset;
 
-	if (priv->ops->read_fifo)
-		return priv->ops->read_fifo(priv, addr_offset);
+	if (cdev->ops->read_fifo)
+		return cdev->ops->read_fifo(cdev, addr_offset);
 	else
 		return -EINVAL;
 }
 
-static u32 m_can_fifo_write(struct m_can_priv *priv,
+static u32 m_can_fifo_write(struct m_can_classdev *cdev,
 			    u32 fpi, unsigned int offset, u32 val)
 {
-	u32 addr_offset = priv->mcfg[MRAM_TXB].off + fpi * TXB_ELEMENT_SIZE +
+	u32 addr_offset = cdev->mcfg[MRAM_TXB].off + fpi * TXB_ELEMENT_SIZE +
 			  offset;
 
-	if (priv->ops->write_fifo)
-		return priv->ops->write_fifo(priv, addr_offset, val);
+	if (cdev->ops->write_fifo)
+		return cdev->ops->write_fifo(cdev, addr_offset, val);
 	else
 		return -EINVAL;
 }
 
-static u32 m_can_fifo_write_no_off(struct m_can_priv *priv,
+static u32 m_can_fifo_write_no_off(struct m_can_classdev *cdev,
 				   u32 fpi, u32 val)
 {
-	if (priv->ops->write_fifo)
-		return priv->ops->write_fifo(priv, fpi, val);
+	if (cdev->ops->write_fifo)
+		return cdev->ops->write_fifo(cdev, fpi, val);
 	else
 		return 0;
 }
 
-static u32 m_can_txe_fifo_read(struct m_can_priv *priv, u32 fgi, u32 offset)
+static u32 m_can_txe_fifo_read(struct m_can_classdev *cdev, u32 fgi, u32 offset)
 {
-	u32 addr_offset = priv->mcfg[MRAM_TXE].off + fgi * TXE_ELEMENT_SIZE +
+	u32 addr_offset = cdev->mcfg[MRAM_TXE].off + fgi * TXE_ELEMENT_SIZE +
 			  offset;
 
-	if (priv->ops->read_fifo)
-		return priv->ops->read_fifo(priv, addr_offset);
+	if (cdev->ops->read_fifo)
+		return cdev->ops->read_fifo(cdev, addr_offset);
 	else
 		return -EINVAL;
 }
 
-static inline bool m_can_tx_fifo_full(struct m_can_priv *priv)
+static inline bool m_can_tx_fifo_full(struct m_can_classdev *cdev)
 {
-		return !!(m_can_read(priv, M_CAN_TXFQS) & TXFQS_TFQF);
+		return !!(m_can_read(cdev, M_CAN_TXFQS) & TXFQS_TFQF);
 }
 
-void m_can_config_endisable(struct m_can_priv *priv, bool enable)
+void m_can_config_endisable(struct m_can_classdev *cdev, bool enable)
 {
-	u32 cccr = m_can_read(priv, M_CAN_CCCR);
+	u32 cccr = m_can_read(cdev, M_CAN_CCCR);
 	u32 timeout = 10;
 	u32 val = 0;
 
 	if (enable) {
 		/* enable m_can configuration */
-		m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT);
+		m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT);
 		udelay(5);
 		/* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */
-		m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE);
+		m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE);
 	} else {
-		m_can_write(priv, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE));
+		m_can_write(cdev, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE));
 	}
 
 	/* there's a delay for module initialization */
 	if (enable)
 		val = CCCR_INIT | CCCR_CCE;
 
-	while ((m_can_read(priv, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) {
+	while ((m_can_read(cdev, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) {
 		if (timeout == 0) {
-			netdev_warn(priv->net, "Failed to init module\n");
+			netdev_warn(cdev->net, "Failed to init module\n");
 			return;
 		}
 		timeout--;
@@ -415,21 +415,21 @@ void m_can_config_endisable(struct m_can_priv *priv, bool enable)
 	}
 }
 
-static inline void m_can_enable_all_interrupts(struct m_can_priv *priv)
+static inline void m_can_enable_all_interrupts(struct m_can_classdev *cdev)
 {
 	/* Only interrupt line 0 is used in this driver */
-	m_can_write(priv, M_CAN_ILE, ILE_EINT0);
+	m_can_write(cdev, M_CAN_ILE, ILE_EINT0);
 }
 
-static inline void m_can_disable_all_interrupts(struct m_can_priv *priv)
+static inline void m_can_disable_all_interrupts(struct m_can_classdev *cdev)
 {
-	m_can_write(priv, M_CAN_ILE, 0x0);
+	m_can_write(cdev, M_CAN_ILE, 0x0);
 }
 
 static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
 {
 	struct net_device_stats *stats = &dev->stats;
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	struct canfd_frame *cf;
 	struct sk_buff *skb;
 	u32 id, fgi, dlc;
@@ -437,7 +437,7 @@ static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
 
 	/* calculate the fifo get index for where to read data */
 	fgi = (rxfs & RXFS_FGI_MASK) >> RXFS_FGI_SHIFT;
-	dlc = m_can_fifo_read(priv, fgi, M_CAN_FIFO_DLC);
+	dlc = m_can_fifo_read(cdev, fgi, M_CAN_FIFO_DLC);
 	if (dlc & RX_BUF_FDF)
 		skb = alloc_canfd_skb(dev, &cf);
 	else
@@ -452,7 +452,7 @@ static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
 	else
 		cf->len = get_can_dlc((dlc >> 16) & 0x0F);
 
-	id = m_can_fifo_read(priv, fgi, M_CAN_FIFO_ID);
+	id = m_can_fifo_read(cdev, fgi, M_CAN_FIFO_ID);
 	if (id & RX_BUF_XTD)
 		cf->can_id = (id & CAN_EFF_MASK) | CAN_EFF_FLAG;
 	else
@@ -471,12 +471,12 @@ static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
 
 		for (i = 0; i < cf->len; i += 4)
 			*(u32 *)(cf->data + i) =
-				m_can_fifo_read(priv, fgi,
+				m_can_fifo_read(cdev, fgi,
 						M_CAN_FIFO_DATA(i / 4));
 	}
 
 	/* acknowledge rx fifo 0 */
-	m_can_write(priv, M_CAN_RXF0A, fgi);
+	m_can_write(cdev, M_CAN_RXF0A, fgi);
 
 	stats->rx_packets++;
 	stats->rx_bytes += cf->len;
@@ -486,11 +486,11 @@ static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
 
 static int m_can_do_rx_poll(struct net_device *dev, int quota)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	u32 pkts = 0;
 	u32 rxfs;
 
-	rxfs = m_can_read(priv, M_CAN_RXF0S);
+	rxfs = m_can_read(cdev, M_CAN_RXF0S);
 	if (!(rxfs & RXFS_FFL_MASK)) {
 		netdev_dbg(dev, "no messages in fifo0\n");
 		return 0;
@@ -504,7 +504,7 @@ static int m_can_do_rx_poll(struct net_device *dev, int quota)
 
 		quota--;
 		pkts++;
-		rxfs = m_can_read(priv, M_CAN_RXF0S);
+		rxfs = m_can_read(cdev, M_CAN_RXF0S);
 	}
 
 	if (pkts)
@@ -539,12 +539,12 @@ static int m_can_handle_lost_msg(struct net_device *dev)
 static int m_can_handle_lec_err(struct net_device *dev,
 				enum m_can_lec_type lec_type)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	struct net_device_stats *stats = &dev->stats;
 	struct can_frame *cf;
 	struct sk_buff *skb;
 
-	priv->can.can_stats.bus_error++;
+	cdev->can.can_stats.bus_error++;
 	stats->rx_errors++;
 
 	/* propagate the error condition to the CAN stack */
@@ -596,51 +596,51 @@ static int m_can_handle_lec_err(struct net_device *dev,
 static int __m_can_get_berr_counter(const struct net_device *dev,
 				    struct can_berr_counter *bec)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	unsigned int ecr;
 
-	ecr = m_can_read(priv, M_CAN_ECR);
+	ecr = m_can_read(cdev, M_CAN_ECR);
 	bec->rxerr = (ecr & ECR_REC_MASK) >> ECR_REC_SHIFT;
 	bec->txerr = (ecr & ECR_TEC_MASK) >> ECR_TEC_SHIFT;
 
 	return 0;
 }
 
-static int m_can_clk_start(struct m_can_priv *priv)
+static int m_can_clk_start(struct m_can_classdev *cdev)
 {
 	int err;
 
-	if (priv->pm_clock_support == 0)
+	if (cdev->pm_clock_support == 0)
 		return 0;
 
-	err = pm_runtime_get_sync(priv->dev);
+	err = pm_runtime_get_sync(cdev->dev);
 	if (err < 0) {
-		pm_runtime_put_noidle(priv->dev);
+		pm_runtime_put_noidle(cdev->dev);
 		return err;
 	}
 
 	return 0;
 }
 
-static void m_can_clk_stop(struct m_can_priv *priv)
+static void m_can_clk_stop(struct m_can_classdev *cdev)
 {
-	if (priv->pm_clock_support)
-		pm_runtime_put_sync(priv->dev);
+	if (cdev->pm_clock_support)
+		pm_runtime_put_sync(cdev->dev);
 }
 
 static int m_can_get_berr_counter(const struct net_device *dev,
 				  struct can_berr_counter *bec)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	int err;
 
-	err = m_can_clk_start(priv);
+	err = m_can_clk_start(cdev);
 	if (err)
 		return err;
 
 	__m_can_get_berr_counter(dev, bec);
 
-	m_can_clk_stop(priv);
+	m_can_clk_stop(cdev);
 
 	return 0;
 }
@@ -648,7 +648,7 @@ static int m_can_get_berr_counter(const struct net_device *dev,
 static int m_can_handle_state_change(struct net_device *dev,
 				     enum can_state new_state)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	struct net_device_stats *stats = &dev->stats;
 	struct can_frame *cf;
 	struct sk_buff *skb;
@@ -658,19 +658,19 @@ static int m_can_handle_state_change(struct net_device *dev,
 	switch (new_state) {
 	case CAN_STATE_ERROR_ACTIVE:
 		/* error warning state */
-		priv->can.can_stats.error_warning++;
-		priv->can.state = CAN_STATE_ERROR_WARNING;
+		cdev->can.can_stats.error_warning++;
+		cdev->can.state = CAN_STATE_ERROR_WARNING;
 		break;
 	case CAN_STATE_ERROR_PASSIVE:
 		/* error passive state */
-		priv->can.can_stats.error_passive++;
-		priv->can.state = CAN_STATE_ERROR_PASSIVE;
+		cdev->can.can_stats.error_passive++;
+		cdev->can.state = CAN_STATE_ERROR_PASSIVE;
 		break;
 	case CAN_STATE_BUS_OFF:
 		/* bus-off state */
-		priv->can.state = CAN_STATE_BUS_OFF;
-		m_can_disable_all_interrupts(priv);
-		priv->can.can_stats.bus_off++;
+		cdev->can.state = CAN_STATE_BUS_OFF;
+		m_can_disable_all_interrupts(cdev);
+		cdev->can.can_stats.bus_off++;
 		can_bus_off(dev);
 		break;
 	default:
@@ -697,7 +697,7 @@ static int m_can_handle_state_change(struct net_device *dev,
 	case CAN_STATE_ERROR_PASSIVE:
 		/* error passive state */
 		cf->can_id |= CAN_ERR_CRTL;
-		ecr = m_can_read(priv, M_CAN_ECR);
+		ecr = m_can_read(cdev, M_CAN_ECR);
 		if (ecr & ECR_RP)
 			cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
 		if (bec.txerr > 127)
@@ -722,25 +722,25 @@ static int m_can_handle_state_change(struct net_device *dev,
 
 static int m_can_handle_state_errors(struct net_device *dev, u32 psr)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	int work_done = 0;
 
 	if ((psr & PSR_EW) &&
-	    (priv->can.state != CAN_STATE_ERROR_WARNING)) {
+	    (cdev->can.state != CAN_STATE_ERROR_WARNING)) {
 		netdev_dbg(dev, "entered error warning state\n");
 		work_done += m_can_handle_state_change(dev,
 						       CAN_STATE_ERROR_WARNING);
 	}
 
 	if ((psr & PSR_EP) &&
-	    (priv->can.state != CAN_STATE_ERROR_PASSIVE)) {
+	    (cdev->can.state != CAN_STATE_ERROR_PASSIVE)) {
 		netdev_dbg(dev, "entered error passive state\n");
 		work_done += m_can_handle_state_change(dev,
 						       CAN_STATE_ERROR_PASSIVE);
 	}
 
 	if ((psr & PSR_BO) &&
-	    (priv->can.state != CAN_STATE_BUS_OFF)) {
+	    (cdev->can.state != CAN_STATE_BUS_OFF)) {
 		netdev_dbg(dev, "entered error bus off state\n");
 		work_done += m_can_handle_state_change(dev,
 						       CAN_STATE_BUS_OFF);
@@ -775,14 +775,14 @@ static inline bool is_lec_err(u32 psr)
 static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
 				   u32 psr)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	int work_done = 0;
 
 	if (irqstatus & IR_RF0L)
 		work_done += m_can_handle_lost_msg(dev);
 
 	/* handle lec errors on the bus */
-	if ((priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
+	if ((cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
 	    is_lec_err(psr))
 		work_done += m_can_handle_lec_err(dev, psr & LEC_UNUSED);
 
@@ -794,15 +794,15 @@ static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
 
 static int m_can_rx_handler(struct net_device *dev, int quota)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	int work_done = 0;
 	u32 irqstatus, psr;
 
-	irqstatus = priv->irqstatus | m_can_read(priv, M_CAN_IR);
+	irqstatus = cdev->irqstatus | m_can_read(cdev, M_CAN_IR);
 	if (!irqstatus)
 		goto end;
 
-	psr = m_can_read(priv, M_CAN_PSR);
+	psr = m_can_read(cdev, M_CAN_PSR);
 	if (irqstatus & IR_ERR_STATE)
 		work_done += m_can_handle_state_errors(dev, psr);
 
@@ -817,11 +817,11 @@ static int m_can_rx_handler(struct net_device *dev, int quota)
 
 static int m_can_rx_peripherial(struct net_device *dev)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 
 	m_can_rx_handler(dev, 1);
 
-	m_can_enable_all_interrupts(priv);
+	m_can_enable_all_interrupts(cdev);
 
 	return 0;
 }
@@ -829,13 +829,13 @@ static int m_can_rx_peripherial(struct net_device *dev)
 static int m_can_poll(struct napi_struct *napi, int quota)
 {
 	struct net_device *dev = napi->dev;
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	int work_done;
 
 	work_done = m_can_rx_handler(dev, quota);
 	if (work_done < quota) {
 		napi_complete_done(napi, work_done);
-		m_can_enable_all_interrupts(priv);
+		m_can_enable_all_interrupts(cdev);
 	}
 
 	return work_done;
@@ -849,11 +849,11 @@ static void m_can_echo_tx_event(struct net_device *dev)
 	int i = 0;
 	unsigned int msg_mark;
 
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	struct net_device_stats *stats = &dev->stats;
 
 	/* read tx event fifo status */
-	m_can_txefs = m_can_read(priv, M_CAN_TXEFS);
+	m_can_txefs = m_can_read(cdev, M_CAN_TXEFS);
 
 	/* Get Tx Event fifo element count */
 	txe_count = (m_can_txefs & TXEFS_EFFL_MASK)
@@ -862,15 +862,15 @@ static void m_can_echo_tx_event(struct net_device *dev)
 	/* Get and process all sent elements */
 	for (i = 0; i < txe_count; i++) {
 		/* retrieve get index */
-		fgi = (m_can_read(priv, M_CAN_TXEFS) & TXEFS_EFGI_MASK)
+		fgi = (m_can_read(cdev, M_CAN_TXEFS) & TXEFS_EFGI_MASK)
 			>> TXEFS_EFGI_SHIFT;
 
 		/* get message marker */
-		msg_mark = (m_can_txe_fifo_read(priv, fgi, 4) &
+		msg_mark = (m_can_txe_fifo_read(cdev, fgi, 4) &
 			    TX_EVENT_MM_MASK) >> TX_EVENT_MM_SHIFT;
 
 		/* ack txe element */
-		m_can_write(priv, M_CAN_TXEFA, (TXEFA_EFAI_MASK &
+		m_can_write(cdev, M_CAN_TXEFA, (TXEFA_EFAI_MASK &
 						(fgi << TXEFA_EFAI_SHIFT)));
 
 		/* update stats */
@@ -882,20 +882,20 @@ static void m_can_echo_tx_event(struct net_device *dev)
 static irqreturn_t m_can_isr(int irq, void *dev_id)
 {
 	struct net_device *dev = (struct net_device *)dev_id;
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	struct net_device_stats *stats = &dev->stats;
 	u32 ir;
 
-	ir = m_can_read(priv, M_CAN_IR);
+	ir = m_can_read(cdev, M_CAN_IR);
 	if (!ir)
 		return IRQ_NONE;
 
 	/* ACK all irqs */
 	if (ir & IR_ALL_INT)
-		m_can_write(priv, M_CAN_IR, ir);
+		m_can_write(cdev, M_CAN_IR, ir);
 
-	if (priv->ops->clear_interrupts)
-		priv->ops->clear_interrupts(priv);
+	if (cdev->ops->clear_interrupts)
+		cdev->ops->clear_interrupts(cdev);
 
 	/* schedule NAPI in case of
 	 * - rx IRQ
@@ -903,15 +903,15 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
 	 * - bus error IRQ and bus error reporting
 	 */
 	if ((ir & IR_RF0N) || (ir & IR_ERR_ALL_30X)) {
-		priv->irqstatus = ir;
-		m_can_disable_all_interrupts(priv);
-		if (!priv->is_peripherial)
-			napi_schedule(&priv->napi);
+		cdev->irqstatus = ir;
+		m_can_disable_all_interrupts(cdev);
+		if (!cdev->is_peripherial)
+			napi_schedule(&cdev->napi);
 		else
 			m_can_rx_peripherial(dev);
 	}
 
-	if (priv->version == 30) {
+	if (cdev->version == 30) {
 		if (ir & IR_TC) {
 			/* Transmission Complete Interrupt*/
 			stats->tx_bytes += can_get_echo_skb(dev, 0);
@@ -925,7 +925,7 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
 			m_can_echo_tx_event(dev);
 			can_led_event(dev, CAN_LED_EVENT_TX);
 			if (netif_queue_stopped(dev) &&
-			    !m_can_tx_fifo_full(priv))
+			    !m_can_tx_fifo_full(cdev))
 				netif_wake_queue(dev);
 		}
 	}
@@ -983,9 +983,9 @@ static const struct can_bittiming_const m_can_data_bittiming_const_31X = {
 
 static int m_can_set_bittiming(struct net_device *dev)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
-	const struct can_bittiming *bt = &priv->can.bittiming;
-	const struct can_bittiming *dbt = &priv->can.data_bittiming;
+	struct m_can_classdev *cdev = netdev_priv(dev);
+	const struct can_bittiming *bt = &cdev->can.bittiming;
+	const struct can_bittiming *dbt = &cdev->can.data_bittiming;
 	u16 brp, sjw, tseg1, tseg2;
 	u32 reg_btp;
 
@@ -995,9 +995,9 @@ static int m_can_set_bittiming(struct net_device *dev)
 	tseg2 = bt->phase_seg2 - 1;
 	reg_btp = (brp << NBTP_NBRP_SHIFT) | (sjw << NBTP_NSJW_SHIFT) |
 		(tseg1 << NBTP_NTSEG1_SHIFT) | (tseg2 << NBTP_NTSEG2_SHIFT);
-	m_can_write(priv, M_CAN_NBTP, reg_btp);
+	m_can_write(cdev, M_CAN_NBTP, reg_btp);
 
-	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
+	if (cdev->can.ctrlmode & CAN_CTRLMODE_FD) {
 		reg_btp = 0;
 		brp = dbt->brp - 1;
 		sjw = dbt->sjw - 1;
@@ -1019,7 +1019,7 @@ static int m_can_set_bittiming(struct net_device *dev)
 			/* Equation based on Bosch's M_CAN User Manual's
 			 * Transmitter Delay Compensation Section
 			 */
-			tdco = (priv->can.clock.freq / 1000) *
+			tdco = (cdev->can.clock.freq / 1000) *
 			       ssp / dbt->bitrate;
 
 			/* Max valid TDCO value is 127 */
@@ -1030,7 +1030,7 @@ static int m_can_set_bittiming(struct net_device *dev)
 			}
 
 			reg_btp |= DBTP_TDC;
-			m_can_write(priv, M_CAN_TDCR,
+			m_can_write(cdev, M_CAN_TDCR,
 				    tdco << TDCR_TDCO_SHIFT);
 		}
 
@@ -1039,7 +1039,7 @@ static int m_can_set_bittiming(struct net_device *dev)
 			   (tseg1 << DBTP_DTSEG1_SHIFT) |
 			   (tseg2 << DBTP_DTSEG2_SHIFT);
 
-		m_can_write(priv, M_CAN_DBTP, reg_btp);
+		m_can_write(cdev, M_CAN_DBTP, reg_btp);
 	}
 
 	return 0;
@@ -1056,63 +1056,63 @@ static int m_can_set_bittiming(struct net_device *dev)
  */
 static void m_can_chip_config(struct net_device *dev)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	u32 cccr, test;
 
-	m_can_config_endisable(priv, true);
+	m_can_config_endisable(cdev, true);
 
 	/* RX Buffer/FIFO Element Size 64 bytes data field */
-	m_can_write(priv, M_CAN_RXESC, M_CAN_RXESC_64BYTES);
+	m_can_write(cdev, M_CAN_RXESC, M_CAN_RXESC_64BYTES);
 
 	/* Accept Non-matching Frames Into FIFO 0 */
-	m_can_write(priv, M_CAN_GFC, 0x0);
+	m_can_write(cdev, M_CAN_GFC, 0x0);
 
-	if (priv->version == 30) {
+	if (cdev->version == 30) {
 		/* only support one Tx Buffer currently */
-		m_can_write(priv, M_CAN_TXBC, (1 << TXBC_NDTB_SHIFT) |
-				priv->mcfg[MRAM_TXB].off);
+		m_can_write(cdev, M_CAN_TXBC, (1 << TXBC_NDTB_SHIFT) |
+				cdev->mcfg[MRAM_TXB].off);
 	} else {
 		/* TX FIFO is used for newer IP Core versions */
-		m_can_write(priv, M_CAN_TXBC,
-			    (priv->mcfg[MRAM_TXB].num << TXBC_TFQS_SHIFT) |
-			    (priv->mcfg[MRAM_TXB].off));
+		m_can_write(cdev, M_CAN_TXBC,
+			    (cdev->mcfg[MRAM_TXB].num << TXBC_TFQS_SHIFT) |
+			    (cdev->mcfg[MRAM_TXB].off));
 	}
 
 	/* support 64 bytes payload */
-	m_can_write(priv, M_CAN_TXESC, TXESC_TBDS_64BYTES);
+	m_can_write(cdev, M_CAN_TXESC, TXESC_TBDS_64BYTES);
 
 	/* TX Event FIFO */
-	if (priv->version == 30) {
-		m_can_write(priv, M_CAN_TXEFC, (1 << TXEFC_EFS_SHIFT) |
-				priv->mcfg[MRAM_TXE].off);
+	if (cdev->version == 30) {
+		m_can_write(cdev, M_CAN_TXEFC, (1 << TXEFC_EFS_SHIFT) |
+				cdev->mcfg[MRAM_TXE].off);
 	} else {
 		/* Full TX Event FIFO is used */
-		m_can_write(priv, M_CAN_TXEFC,
-			    ((priv->mcfg[MRAM_TXE].num << TXEFC_EFS_SHIFT)
+		m_can_write(cdev, M_CAN_TXEFC,
+			    ((cdev->mcfg[MRAM_TXE].num << TXEFC_EFS_SHIFT)
 			     & TXEFC_EFS_MASK) |
-			    priv->mcfg[MRAM_TXE].off);
+			    cdev->mcfg[MRAM_TXE].off);
 	}
 
 	/* rx fifo configuration, blocking mode, fifo size 1 */
-	m_can_write(priv, M_CAN_RXF0C,
-		    (priv->mcfg[MRAM_RXF0].num << RXFC_FS_SHIFT) |
-		     priv->mcfg[MRAM_RXF0].off);
+	m_can_write(cdev, M_CAN_RXF0C,
+		    (cdev->mcfg[MRAM_RXF0].num << RXFC_FS_SHIFT) |
+		     cdev->mcfg[MRAM_RXF0].off);
 
-	m_can_write(priv, M_CAN_RXF1C,
-		    (priv->mcfg[MRAM_RXF1].num << RXFC_FS_SHIFT) |
-		     priv->mcfg[MRAM_RXF1].off);
+	m_can_write(cdev, M_CAN_RXF1C,
+		    (cdev->mcfg[MRAM_RXF1].num << RXFC_FS_SHIFT) |
+		     cdev->mcfg[MRAM_RXF1].off);
 
-	cccr = m_can_read(priv, M_CAN_CCCR);
-	test = m_can_read(priv, M_CAN_TEST);
+	cccr = m_can_read(cdev, M_CAN_CCCR);
+	test = m_can_read(cdev, M_CAN_TEST);
 	test &= ~TEST_LBCK;
-	if (priv->version == 30) {
+	if (cdev->version == 30) {
 	/* Version 3.0.x */
 
 		cccr &= ~(CCCR_TEST | CCCR_MON |
 			(CCCR_CMR_MASK << CCCR_CMR_SHIFT) |
 			(CCCR_CME_MASK << CCCR_CME_SHIFT));
 
-		if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
+		if (cdev->can.ctrlmode & CAN_CTRLMODE_FD)
 			cccr |= CCCR_CME_CANFD_BRS << CCCR_CME_SHIFT;
 
 	} else {
@@ -1121,61 +1121,61 @@ static void m_can_chip_config(struct net_device *dev)
 			  CCCR_NISO);
 
 		/* Only 3.2.x has NISO Bit implemented */
-		if (priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
+		if (cdev->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
 			cccr |= CCCR_NISO;
 
-		if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
+		if (cdev->can.ctrlmode & CAN_CTRLMODE_FD)
 			cccr |= (CCCR_BRSE | CCCR_FDOE);
 	}
 
 	/* Loopback Mode */
-	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
+	if (cdev->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
 		cccr |= CCCR_TEST | CCCR_MON;
 		test |= TEST_LBCK;
 	}
 
 	/* Enable Monitoring (all versions) */
-	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
+	if (cdev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 		cccr |= CCCR_MON;
 
 	/* Write config */
-	m_can_write(priv, M_CAN_CCCR, cccr);
-	m_can_write(priv, M_CAN_TEST, test);
+	m_can_write(cdev, M_CAN_CCCR, cccr);
+	m_can_write(cdev, M_CAN_TEST, test);
 
 	/* Enable interrupts */
-	m_can_write(priv, M_CAN_IR, IR_ALL_INT);
-	if (!(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
-		if (priv->version == 30)
-			m_can_write(priv, M_CAN_IE, IR_ALL_INT &
+	m_can_write(cdev, M_CAN_IR, IR_ALL_INT);
+	if (!(cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
+		if (cdev->version == 30)
+			m_can_write(cdev, M_CAN_IE, IR_ALL_INT &
 				    ~(IR_ERR_LEC_30X));
 		else
-			m_can_write(priv, M_CAN_IE, IR_ALL_INT &
+			m_can_write(cdev, M_CAN_IE, IR_ALL_INT &
 				    ~(IR_ERR_LEC_31X));
 	else
-		m_can_write(priv, M_CAN_IE, IR_ALL_INT);
+		m_can_write(cdev, M_CAN_IE, IR_ALL_INT);
 
 	/* route all interrupts to INT0 */
-	m_can_write(priv, M_CAN_ILS, ILS_ALL_INT0);
+	m_can_write(cdev, M_CAN_ILS, ILS_ALL_INT0);
 
 	/* set bittiming params */
 	m_can_set_bittiming(dev);
 
-	m_can_config_endisable(priv, false);
+	m_can_config_endisable(cdev, false);
 
-	if (priv->ops->init)
-		priv->ops->init(priv);
+	if (cdev->ops->init)
+		cdev->ops->init(cdev);
 }
 
 static void m_can_start(struct net_device *dev)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 
 	/* basic m_can configuration */
 	m_can_chip_config(dev);
 
-	priv->can.state = CAN_STATE_ERROR_ACTIVE;
+	cdev->can.state = CAN_STATE_ERROR_ACTIVE;
 
-	m_can_enable_all_interrupts(priv);
+	m_can_enable_all_interrupts(cdev);
 }
 
 static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
@@ -1197,7 +1197,7 @@ static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
  * else it returns the release and step coded as:
  * return value = 10 * <release> + 1 * <step>
  */
-static int m_can_check_core_release(struct m_can_priv *priv)
+static int m_can_check_core_release(struct m_can_classdev *cdev)
 {
 	u32 crel_reg;
 	u8 rel;
@@ -1207,7 +1207,7 @@ static int m_can_check_core_release(struct m_can_priv *priv)
 	/* Read Core Release Version and split into version number
 	 * Example: Version 3.2.1 => rel = 3; step = 2; substep = 1;
 	 */
-	crel_reg = m_can_read(priv, M_CAN_CREL);
+	crel_reg = m_can_read(cdev, M_CAN_CREL);
 	rel = (u8)((crel_reg & CREL_REL_MASK) >> CREL_REL_SHIFT);
 	step = (u8)((crel_reg & CREL_STEP_MASK) >> CREL_STEP_SHIFT);
 
@@ -1225,19 +1225,19 @@ static int m_can_check_core_release(struct m_can_priv *priv)
 /* Selectable Non ISO support only in version 3.2.x
  * This function checks if the bit is writable.
  */
-static bool m_can_niso_supported(struct m_can_priv *priv)
+static bool m_can_niso_supported(struct m_can_classdev *cdev)
 {
 	u32 cccr_reg, cccr_poll = 0;
 	int niso_timeout = -ETIMEDOUT;
 	int i;
 
-	m_can_config_endisable(priv, true);
-	cccr_reg = m_can_read(priv, M_CAN_CCCR);
+	m_can_config_endisable(cdev, true);
+	cccr_reg = m_can_read(cdev, M_CAN_CCCR);
 	cccr_reg |= CCCR_NISO;
-	m_can_write(priv, M_CAN_CCCR, cccr_reg);
+	m_can_write(cdev, M_CAN_CCCR, cccr_reg);
 
 	for (i = 0; i <= 10; i++) {
-		cccr_poll = m_can_read(priv, M_CAN_CCCR);
+		cccr_poll = m_can_read(cdev, M_CAN_CCCR);
 		if (cccr_poll == cccr_reg) {
 			niso_timeout = 0;
 			break;
@@ -1248,15 +1248,15 @@ static bool m_can_niso_supported(struct m_can_priv *priv)
 
 	/* Clear NISO */
 	cccr_reg &= ~(CCCR_NISO);
-	m_can_write(priv, M_CAN_CCCR, cccr_reg);
+	m_can_write(cdev, M_CAN_CCCR, cccr_reg);
 
-	m_can_config_endisable(priv, false);
+	m_can_config_endisable(cdev, false);
 
 	/* return false if time out (-ETIMEDOUT), else return true */
 	return !niso_timeout;
 }
 
-static int m_can_dev_setup(struct m_can_priv *m_can_dev)
+static int m_can_dev_setup(struct m_can_classdev *m_can_dev)
 {
 	struct net_device *dev = m_can_dev->net;
 	int m_can_version;
@@ -1333,30 +1333,30 @@ static int m_can_dev_setup(struct m_can_priv *m_can_dev)
 
 static void m_can_stop(struct net_device *dev)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 
 	/* disable all interrupts */
-	m_can_disable_all_interrupts(priv);
+	m_can_disable_all_interrupts(cdev);
 
 	/* set the state as STOPPED */
-	priv->can.state = CAN_STATE_STOPPED;
+	cdev->can.state = CAN_STATE_STOPPED;
 }
 
 static int m_can_close(struct net_device *dev)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 
 	netif_stop_queue(dev);
-	if (!priv->is_peripherial)
-		napi_disable(&priv->napi);
+	if (!cdev->is_peripherial)
+		napi_disable(&cdev->napi);
 	m_can_stop(dev);
-	m_can_clk_stop(priv);
+	m_can_clk_stop(cdev);
 	free_irq(dev->irq, dev);
 
-	if (priv->is_peripherial) {
-		priv->tx_skb = NULL;
-		destroy_workqueue(priv->tx_wq);
-		priv->tx_wq = NULL;
+	if (cdev->is_peripherial) {
+		cdev->tx_skb = NULL;
+		destroy_workqueue(cdev->tx_wq);
+		cdev->tx_wq = NULL;
 	}
 
 	close_candev(dev);
@@ -1367,23 +1367,23 @@ static int m_can_close(struct net_device *dev)
 
 static int m_can_next_echo_skb_occupied(struct net_device *dev, int putidx)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	/*get wrap around for loopback skb index */
-	unsigned int wrap = priv->can.echo_skb_max;
+	unsigned int wrap = cdev->can.echo_skb_max;
 	int next_idx;
 
 	/* calculate next index */
 	next_idx = (++putidx >= wrap ? 0 : putidx);
 
 	/* check if occupied */
-	return !!priv->can.echo_skb[next_idx];
+	return !!cdev->can.echo_skb[next_idx];
 }
 
-static netdev_tx_t m_can_tx_handler(struct m_can_priv *priv)
+static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
 {
-	struct canfd_frame *cf = (struct canfd_frame *)priv->tx_skb->data;
-	struct net_device *dev = priv->net;
-	struct sk_buff *skb = priv->tx_skb;
+	struct canfd_frame *cf = (struct canfd_frame *)cdev->tx_skb->data;
+	struct net_device *dev = cdev->net;
+	struct sk_buff *skb = cdev->tx_skb;
 	u32 id, cccr, fdflags;
 	int i;
 	int putidx;
@@ -1400,23 +1400,23 @@ static netdev_tx_t m_can_tx_handler(struct m_can_priv *priv)
 	if (cf->can_id & CAN_RTR_FLAG)
 		id |= TX_BUF_RTR;
 
-	if (priv->version == 30) {
+	if (cdev->version == 30) {
 		netif_stop_queue(dev);
 
 		/* message ram configuration */
-		m_can_fifo_write(priv, 0, M_CAN_FIFO_ID, id);
-		m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC,
+		m_can_fifo_write(cdev, 0, M_CAN_FIFO_ID, id);
+		m_can_fifo_write(cdev, 0, M_CAN_FIFO_DLC,
 				 can_len2dlc(cf->len) << 16);
 
 		for (i = 0; i < cf->len; i += 4)
-			m_can_fifo_write(priv, 0,
+			m_can_fifo_write(cdev, 0,
 					 M_CAN_FIFO_DATA(i / 4),
 					 *(u32 *)(cf->data + i));
 
 		can_put_echo_skb(skb, dev, 0);
 
-		if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
-			cccr = m_can_read(priv, M_CAN_CCCR);
+		if (cdev->can.ctrlmode & CAN_CTRLMODE_FD) {
+			cccr = m_can_read(cdev, M_CAN_CCCR);
 			cccr &= ~(CCCR_CMR_MASK << CCCR_CMR_SHIFT);
 			if (can_is_canfd_skb(skb)) {
 				if (cf->flags & CANFD_BRS)
@@ -1428,16 +1428,16 @@ static netdev_tx_t m_can_tx_handler(struct m_can_priv *priv)
 			} else {
 				cccr |= CCCR_CMR_CAN << CCCR_CMR_SHIFT;
 			}
-			m_can_write(priv, M_CAN_CCCR, cccr);
+			m_can_write(cdev, M_CAN_CCCR, cccr);
 		}
-		m_can_write(priv, M_CAN_TXBTIE, 0x1);
-		m_can_write(priv, M_CAN_TXBAR, 0x1);
+		m_can_write(cdev, M_CAN_TXBTIE, 0x1);
+		m_can_write(cdev, M_CAN_TXBAR, 0x1);
 		/* End of xmit function for version 3.0.x */
 	} else {
 		/* Transmit routine for version >= v3.1.x */
 
 		/* Check if FIFO full */
-		if (m_can_tx_fifo_full(priv)) {
+		if (m_can_tx_fifo_full(cdev)) {
 			/* This shouldn't happen */
 			netif_stop_queue(dev);
 			netdev_warn(dev,
@@ -1446,10 +1446,10 @@ static netdev_tx_t m_can_tx_handler(struct m_can_priv *priv)
 		}
 
 		/* get put index for frame */
-		putidx = ((m_can_read(priv, M_CAN_TXFQS) & TXFQS_TFQPI_MASK)
+		putidx = ((m_can_read(cdev, M_CAN_TXFQS) & TXFQS_TFQPI_MASK)
 				  >> TXFQS_TFQPI_SHIFT);
 		/* Write ID Field to FIFO Element */
-		m_can_fifo_write(priv, putidx, M_CAN_FIFO_ID, id);
+		m_can_fifo_write(cdev, putidx, M_CAN_FIFO_ID, id);
 
 		/* get CAN FD configuration of frame */
 		fdflags = 0;
@@ -1464,14 +1464,14 @@ static netdev_tx_t m_can_tx_handler(struct m_can_priv *priv)
 		 * it is used in TX interrupt for
 		 * sending the correct echo frame
 		 */
-		m_can_fifo_write(priv, putidx, M_CAN_FIFO_DLC,
+		m_can_fifo_write(cdev, putidx, M_CAN_FIFO_DLC,
 				 ((putidx << TX_BUF_MM_SHIFT) &
 				  TX_BUF_MM_MASK) |
 				 (can_len2dlc(cf->len) << 16) |
 				 fdflags | TX_BUF_EFC);
 
 		for (i = 0; i < cf->len; i += 4)
-			m_can_fifo_write(priv, putidx, M_CAN_FIFO_DATA(i / 4),
+			m_can_fifo_write(cdev, putidx, M_CAN_FIFO_DATA(i / 4),
 					 *(u32 *)(cf->data + i));
 
 		/* Push loopback echo.
@@ -1480,10 +1480,10 @@ static netdev_tx_t m_can_tx_handler(struct m_can_priv *priv)
 		can_put_echo_skb(skb, dev, putidx);
 
 		/* Enable TX FIFO element to start transfer  */
-		m_can_write(priv, M_CAN_TXBAR, (1 << putidx));
+		m_can_write(cdev, M_CAN_TXBAR, (1 << putidx));
 
 		/* stop network queue if fifo full */
-		if (m_can_tx_fifo_full(priv) ||
+		if (m_can_tx_fifo_full(cdev) ||
 		    m_can_next_echo_skb_occupied(dev, putidx))
 			netif_stop_queue(dev);
 	}
@@ -1493,35 +1493,35 @@ static netdev_tx_t m_can_tx_handler(struct m_can_priv *priv)
 
 static void m_can_tx_work_queue(struct work_struct *ws)
 {
-	struct m_can_priv *priv = container_of(ws, struct m_can_priv,
+	struct m_can_classdev *cdev = container_of(ws, struct m_can_classdev,
 						tx_work);
 	netdev_tx_t ret;
 
-	ret = m_can_tx_handler(priv);
+	ret = m_can_tx_handler(cdev);
 	if (ret == NETDEV_TX_OK)
-		priv->tx_skb = NULL;
+		cdev->tx_skb = NULL;
 }
 
 static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
 				    struct net_device *dev)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 
 	if (can_dropped_invalid_skb(dev, skb))
 		return NETDEV_TX_OK;
 
-	if (priv->is_peripherial) {
-		if (priv->tx_skb) {
+	if (cdev->is_peripherial) {
+		if (cdev->tx_skb) {
 			netdev_err(dev, "hard_xmit called while tx busy\n");
 			return NETDEV_TX_BUSY;
 		}
 
-		priv->tx_skb = skb;
-		netif_stop_queue(priv->net);
-		queue_work(priv->tx_wq, &priv->tx_work);
+		cdev->tx_skb = skb;
+		netif_stop_queue(cdev->net);
+		queue_work(cdev->tx_wq, &cdev->tx_work);
 	} else {
-		priv->tx_skb = skb;
-		return m_can_tx_handler(priv);
+		cdev->tx_skb = skb;
+		return m_can_tx_handler(cdev);
 	}
 
 	return NETDEV_TX_OK;
@@ -1529,10 +1529,10 @@ static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
 
 static int m_can_open(struct net_device *dev)
 {
-	struct m_can_priv *priv = netdev_priv(dev);
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	int err;
 
-	err = m_can_clk_start(priv);
+	err = m_can_clk_start(cdev);
 	if (err)
 		return err;
 
@@ -1544,16 +1544,16 @@ static int m_can_open(struct net_device *dev)
 	}
 
 	/* register interrupt handler */
-	if (priv->is_peripherial) {
-		priv->tx_skb = NULL;
-		priv->tx_wq = alloc_workqueue("mcan_wq",
+	if (cdev->is_peripherial) {
+		cdev->tx_skb = NULL;
+		cdev->tx_wq = alloc_workqueue("mcan_wq",
 					      WQ_FREEZABLE | WQ_MEM_RECLAIM, 0);
-		if (!priv->tx_wq) {
+		if (!cdev->tx_wq) {
 			err = -ENOMEM;
 			goto out_wq_fail;
 		}
 
-		INIT_WORK(&priv->tx_work, m_can_tx_work_queue);
+		INIT_WORK(&cdev->tx_work, m_can_tx_work_queue);
 
 		err = request_threaded_irq(dev->irq, NULL, m_can_isr,
 					   IRQF_ONESHOT | IRQF_TRIGGER_FALLING,
@@ -1573,20 +1573,20 @@ static int m_can_open(struct net_device *dev)
 
 	can_led_event(dev, CAN_LED_EVENT_OPEN);
 
-	if (!priv->is_peripherial)
-		napi_enable(&priv->napi);
+	if (!cdev->is_peripherial)
+		napi_enable(&cdev->napi);
 
 	netif_start_queue(dev);
 
 	return 0;
 
 exit_irq_fail:
-	if (priv->is_peripherial)
-		destroy_workqueue(priv->tx_wq);
+	if (cdev->is_peripherial)
+		destroy_workqueue(cdev->tx_wq);
 out_wq_fail:
 	close_candev(dev);
 exit_disable_clks:
-	m_can_clk_stop(priv);
+	m_can_clk_stop(cdev);
 	return err;
 }
 
@@ -1605,61 +1605,61 @@ static int register_m_can_dev(struct net_device *dev)
 	return register_candev(dev);
 }
 
-static void m_can_of_parse_mram(struct m_can_priv *priv,
+static void m_can_of_parse_mram(struct m_can_classdev *cdev,
 				const u32 *mram_config_vals)
 {
-	priv->mcfg[MRAM_SIDF].off = mram_config_vals[0];
-	priv->mcfg[MRAM_SIDF].num = mram_config_vals[1];
-	priv->mcfg[MRAM_XIDF].off = priv->mcfg[MRAM_SIDF].off +
-			priv->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE;
-	priv->mcfg[MRAM_XIDF].num = mram_config_vals[2];
-	priv->mcfg[MRAM_RXF0].off = priv->mcfg[MRAM_XIDF].off +
-			priv->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE;
-	priv->mcfg[MRAM_RXF0].num = mram_config_vals[3] &
+	cdev->mcfg[MRAM_SIDF].off = mram_config_vals[0];
+	cdev->mcfg[MRAM_SIDF].num = mram_config_vals[1];
+	cdev->mcfg[MRAM_XIDF].off = cdev->mcfg[MRAM_SIDF].off +
+			cdev->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE;
+	cdev->mcfg[MRAM_XIDF].num = mram_config_vals[2];
+	cdev->mcfg[MRAM_RXF0].off = cdev->mcfg[MRAM_XIDF].off +
+			cdev->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE;
+	cdev->mcfg[MRAM_RXF0].num = mram_config_vals[3] &
 			(RXFC_FS_MASK >> RXFC_FS_SHIFT);
-	priv->mcfg[MRAM_RXF1].off = priv->mcfg[MRAM_RXF0].off +
-			priv->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE;
-	priv->mcfg[MRAM_RXF1].num = mram_config_vals[4] &
+	cdev->mcfg[MRAM_RXF1].off = cdev->mcfg[MRAM_RXF0].off +
+			cdev->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE;
+	cdev->mcfg[MRAM_RXF1].num = mram_config_vals[4] &
 			(RXFC_FS_MASK >> RXFC_FS_SHIFT);
-	priv->mcfg[MRAM_RXB].off = priv->mcfg[MRAM_RXF1].off +
-			priv->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE;
-	priv->mcfg[MRAM_RXB].num = mram_config_vals[5];
-	priv->mcfg[MRAM_TXE].off = priv->mcfg[MRAM_RXB].off +
-			priv->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE;
-	priv->mcfg[MRAM_TXE].num = mram_config_vals[6];
-	priv->mcfg[MRAM_TXB].off = priv->mcfg[MRAM_TXE].off +
-			priv->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE;
-	priv->mcfg[MRAM_TXB].num = mram_config_vals[7] &
+	cdev->mcfg[MRAM_RXB].off = cdev->mcfg[MRAM_RXF1].off +
+			cdev->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE;
+	cdev->mcfg[MRAM_RXB].num = mram_config_vals[5];
+	cdev->mcfg[MRAM_TXE].off = cdev->mcfg[MRAM_RXB].off +
+			cdev->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE;
+	cdev->mcfg[MRAM_TXE].num = mram_config_vals[6];
+	cdev->mcfg[MRAM_TXB].off = cdev->mcfg[MRAM_TXE].off +
+			cdev->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE;
+	cdev->mcfg[MRAM_TXB].num = mram_config_vals[7] &
 			(TXBC_NDTB_MASK >> TXBC_NDTB_SHIFT);
 
-	dev_dbg(priv->dev,
+	dev_dbg(cdev->dev,
 		"sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",
-		priv->mcfg[MRAM_SIDF].off, priv->mcfg[MRAM_SIDF].num,
-		priv->mcfg[MRAM_XIDF].off, priv->mcfg[MRAM_XIDF].num,
-		priv->mcfg[MRAM_RXF0].off, priv->mcfg[MRAM_RXF0].num,
-		priv->mcfg[MRAM_RXF1].off, priv->mcfg[MRAM_RXF1].num,
-		priv->mcfg[MRAM_RXB].off, priv->mcfg[MRAM_RXB].num,
-		priv->mcfg[MRAM_TXE].off, priv->mcfg[MRAM_TXE].num,
-		priv->mcfg[MRAM_TXB].off, priv->mcfg[MRAM_TXB].num);
+		cdev->mcfg[MRAM_SIDF].off, cdev->mcfg[MRAM_SIDF].num,
+		cdev->mcfg[MRAM_XIDF].off, cdev->mcfg[MRAM_XIDF].num,
+		cdev->mcfg[MRAM_RXF0].off, cdev->mcfg[MRAM_RXF0].num,
+		cdev->mcfg[MRAM_RXF1].off, cdev->mcfg[MRAM_RXF1].num,
+		cdev->mcfg[MRAM_RXB].off, cdev->mcfg[MRAM_RXB].num,
+		cdev->mcfg[MRAM_TXE].off, cdev->mcfg[MRAM_TXE].num,
+		cdev->mcfg[MRAM_TXB].off, cdev->mcfg[MRAM_TXB].num);
 }
 
-void m_can_init_ram(struct m_can_priv *priv)
+void m_can_init_ram(struct m_can_classdev *cdev)
 {
 	int end, i, start;
 
 	/* initialize the entire Message RAM in use to avoid possible
 	 * ECC/parity checksum errors when reading an uninitialized buffer
 	 */
-	start = priv->mcfg[MRAM_SIDF].off;
-	end = priv->mcfg[MRAM_TXB].off +
-		priv->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
+	start = cdev->mcfg[MRAM_SIDF].off;
+	end = cdev->mcfg[MRAM_TXB].off +
+		cdev->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
 
 	for (i = start; i < end; i += 4)
-		m_can_fifo_write_no_off(priv, i, 0x0);
+		m_can_fifo_write_no_off(cdev, i, 0x0);
 }
 EXPORT_SYMBOL_GPL(m_can_init_ram);
 
-int m_can_class_get_clocks(struct m_can_priv *m_can_dev)
+int m_can_class_get_clocks(struct m_can_classdev *m_can_dev)
 {
 	int ret = 0;
 
@@ -1675,9 +1675,9 @@ int m_can_class_get_clocks(struct m_can_priv *m_can_dev)
 }
 EXPORT_SYMBOL_GPL(m_can_class_get_clocks);
 
-struct m_can_priv *m_can_class_allocate_dev(struct device *dev)
+struct m_can_classdev *m_can_class_allocate_dev(struct device *dev)
 {
-	struct m_can_priv *class_dev = NULL;
+	struct m_can_classdev *class_dev = NULL;
 	u32 mram_config_vals[MRAM_CFG_LEN];
 	struct net_device *net_dev;
 	u32 tx_fifo_size;
@@ -1706,7 +1706,7 @@ struct m_can_priv *m_can_class_allocate_dev(struct device *dev)
 
 	class_dev = netdev_priv(net_dev);
 	if (!class_dev) {
-		dev_err(dev, "Failed to init netdev private");
+		dev_err(dev, "Failed to init netdev cdevate");
 		goto out;
 	}
 
@@ -1720,7 +1720,7 @@ struct m_can_priv *m_can_class_allocate_dev(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(m_can_class_allocate_dev);
 
-int m_can_class_register(struct m_can_priv *m_can_dev)
+int m_can_class_register(struct m_can_classdev *m_can_dev)
 {
 	int ret;
 
@@ -1768,18 +1768,18 @@ EXPORT_SYMBOL_GPL(m_can_class_register);
 int m_can_class_suspend(struct device *dev)
 {
 	struct net_device *ndev = dev_get_drvdata(dev);
-	struct m_can_priv *priv = netdev_priv(ndev);
+	struct m_can_classdev *cdev = netdev_priv(ndev);
 
 	if (netif_running(ndev)) {
 		netif_stop_queue(ndev);
 		netif_device_detach(ndev);
 		m_can_stop(ndev);
-		m_can_clk_stop(priv);
+		m_can_clk_stop(cdev);
 	}
 
 	pinctrl_pm_select_sleep_state(dev);
 
-	priv->can.state = CAN_STATE_SLEEPING;
+	cdev->can.state = CAN_STATE_SLEEPING;
 
 	return 0;
 }
@@ -1788,20 +1788,20 @@ EXPORT_SYMBOL_GPL(m_can_class_suspend);
 int m_can_class_resume(struct device *dev)
 {
 	struct net_device *ndev = dev_get_drvdata(dev);
-	struct m_can_priv *priv = netdev_priv(ndev);
+	struct m_can_classdev *cdev = netdev_priv(ndev);
 
 	pinctrl_pm_select_default_state(dev);
 
-	priv->can.state = CAN_STATE_ERROR_ACTIVE;
+	cdev->can.state = CAN_STATE_ERROR_ACTIVE;
 
 	if (netif_running(ndev)) {
 		int ret;
 
-		ret = m_can_clk_start(priv);
+		ret = m_can_clk_start(cdev);
 		if (ret)
 			return ret;
 
-		m_can_init_ram(priv);
+		m_can_init_ram(cdev);
 		m_can_start(ndev);
 		netif_device_attach(ndev);
 		netif_start_queue(ndev);
@@ -1811,7 +1811,7 @@ int m_can_class_resume(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(m_can_class_resume);
 
-void m_can_class_unregister(struct m_can_priv *m_can_dev)
+void m_can_class_unregister(struct m_can_classdev *m_can_dev)
 {
 	unregister_candev(m_can_dev->net);
 
diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h
index b60f27dd9f33..1299cc747194 100644
--- a/drivers/net/can/m_can/m_can.h
+++ b/drivers/net/can/m_can/m_can.h
@@ -57,19 +57,19 @@ struct mram_cfg {
 	u8  num;
 };
 
-struct m_can_priv;
+struct m_can_classdev;
 struct m_can_ops {
 	/* Device specific call backs */
-	int (*clear_interrupts)(struct m_can_priv *m_can_class);
-	u32 (*read_reg)(struct m_can_priv *m_can_class, int reg);
-	int (*write_reg)(struct m_can_priv *m_can_class, int reg, int val);
-	u32 (*read_fifo)(struct m_can_priv *m_can_class, int addr_offset);
-	int (*write_fifo)(struct m_can_priv *m_can_class, int addr_offset,
+	int (*clear_interrupts)(struct m_can_classdev *m_can_class);
+	u32 (*read_reg)(struct m_can_classdev *m_can_class, int reg);
+	int (*write_reg)(struct m_can_classdev *m_can_class, int reg, int val);
+	u32 (*read_fifo)(struct m_can_classdev *m_can_class, int addr_offset);
+	int (*write_fifo)(struct m_can_classdev *m_can_class, int addr_offset,
 			  int val);
-	int (*init)(struct m_can_priv *m_can_class);
+	int (*init)(struct m_can_classdev *m_can_class);
 };
 
-struct m_can_priv {
+struct m_can_classdev {
 	struct can_priv can;
 	struct napi_struct napi;
 	struct net_device *net;
@@ -98,12 +98,12 @@ struct m_can_priv {
 	struct mram_cfg mcfg[MRAM_CFG_NUM];
 };
 
-struct m_can_priv *m_can_class_allocate_dev(struct device *dev);
-int m_can_class_register(struct m_can_priv *m_can_dev);
-void m_can_class_unregister(struct m_can_priv *m_can_dev);
-int m_can_class_get_clocks(struct m_can_priv *m_can_dev);
-void m_can_init_ram(struct m_can_priv *priv);
-void m_can_config_endisable(struct m_can_priv *priv, bool enable);
+struct m_can_classdev *m_can_class_allocate_dev(struct device *dev);
+int m_can_class_register(struct m_can_classdev *m_can_dev);
+void m_can_class_unregister(struct m_can_classdev *m_can_dev);
+int m_can_class_get_clocks(struct m_can_classdev *m_can_dev);
+void m_can_init_ram(struct m_can_classdev *priv);
+void m_can_config_endisable(struct m_can_classdev *priv, bool enable);
 
 int m_can_class_suspend(struct device *dev);
 int m_can_class_resume(struct device *dev);
diff --git a/drivers/net/can/m_can/m_can_platform.c b/drivers/net/can/m_can/m_can_platform.c
index b02d49f9ee4c..601be42b9a4b 100644
--- a/drivers/net/can/m_can/m_can_platform.c
+++ b/drivers/net/can/m_can/m_can_platform.c
@@ -14,7 +14,7 @@ struct m_can_plat_priv {
 	void __iomem *mram_base;
 };
 
-static u32 iomap_read_reg(struct m_can_priv *cdev, int reg)
+static u32 iomap_read_reg(struct m_can_classdev *cdev, int reg)
 {
 	struct m_can_plat_priv *priv =
 			(struct m_can_plat_priv *)cdev->device_data;
@@ -22,7 +22,7 @@ static u32 iomap_read_reg(struct m_can_priv *cdev, int reg)
 	return readl(priv->base + reg);
 }
 
-static u32 iomap_read_fifo(struct m_can_priv *cdev, int offset)
+static u32 iomap_read_fifo(struct m_can_classdev *cdev, int offset)
 {
 	struct m_can_plat_priv *priv =
 			(struct m_can_plat_priv *)cdev->device_data;
@@ -30,7 +30,7 @@ static u32 iomap_read_fifo(struct m_can_priv *cdev, int offset)
 	return readl(priv->mram_base + offset);
 }
 
-static int iomap_write_reg(struct m_can_priv *cdev, int reg, int val)
+static int iomap_write_reg(struct m_can_classdev *cdev, int reg, int val)
 {
 	struct m_can_plat_priv *priv =
 			(struct m_can_plat_priv *)cdev->device_data;
@@ -40,7 +40,7 @@ static int iomap_write_reg(struct m_can_priv *cdev, int reg, int val)
 	return 0;
 }
 
-static int iomap_write_fifo(struct m_can_priv *cdev, int offset, int val)
+static int iomap_write_fifo(struct m_can_classdev *cdev, int offset, int val)
 {
 	struct m_can_plat_priv *priv =
 			(struct m_can_plat_priv *)cdev->device_data;
@@ -59,7 +59,7 @@ static struct m_can_ops m_can_plat_ops = {
 
 static int m_can_plat_probe(struct platform_device *pdev)
 {
-	struct m_can_priv *mcan_class;
+	struct m_can_classdev *mcan_class;
 	struct m_can_plat_priv *priv;
 	struct resource *res;
 	void __iomem *addr;
@@ -131,7 +131,7 @@ static __maybe_unused int m_can_resume(struct device *dev)
 static int m_can_plat_remove(struct platform_device *pdev)
 {
 	struct net_device *dev = platform_get_drvdata(pdev);
-	struct m_can_priv *mcan_class = netdev_priv(dev);
+	struct m_can_classdev *mcan_class = netdev_priv(dev);
 
 	m_can_class_unregister(mcan_class);
 
@@ -143,7 +143,7 @@ static int m_can_plat_remove(struct platform_device *pdev)
 static int __maybe_unused m_can_runtime_suspend(struct device *dev)
 {
 	struct net_device *ndev = dev_get_drvdata(dev);
-	struct m_can_priv *mcan_class = netdev_priv(ndev);
+	struct m_can_classdev *mcan_class = netdev_priv(ndev);
 
 	m_can_class_suspend(dev);
 
@@ -156,7 +156,7 @@ static int __maybe_unused m_can_runtime_suspend(struct device *dev)
 static int __maybe_unused m_can_runtime_resume(struct device *dev)
 {
 	struct net_device *ndev = dev_get_drvdata(dev);
-	struct m_can_priv *mcan_class = netdev_priv(ndev);
+	struct m_can_classdev *mcan_class = netdev_priv(ndev);
 	int err;
 
 	err = clk_prepare_enable(mcan_class->hclk);
-- 
2.20.1.390.gb5101f9297


^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v7 3/4] dt-bindings: can: tcan4x5x: Add DT bindings for TCAN4x5X driver
  2019-03-05 15:52 [PATCH v7 1/4] can: m_can: Create a m_can platform framework Dan Murphy
  2019-03-05 15:52 ` [PATCH v7 2/4] can: m_can: Rename m_can_priv to m_can_classdev Dan Murphy
@ 2019-03-05 15:52 ` Dan Murphy
  2019-03-05 15:52 ` [PATCH v7 4/4] can: tcan4x5x: Add tcan4x5x driver to the kernel Dan Murphy
  2019-03-08 10:10 ` [PATCH v7 1/4] can: m_can: Create a m_can platform framework Wolfgang Grandegger
  3 siblings, 0 replies; 18+ messages in thread
From: Dan Murphy @ 2019-03-05 15:52 UTC (permalink / raw)
  To: wg, mkl, davem; +Cc: linux-can, netdev, linux-kernel, Dan Murphy

DT binding documentation for TI TCAN4x5x driver.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
---

v7 - Made device state optional - https://lore.kernel.org/patchwork/patch/1047218/

v6 - No changes - https://lore.kernel.org/patchwork/patch/1042445/

 .../devicetree/bindings/net/can/tcan4x5x.txt  | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/can/tcan4x5x.txt

diff --git a/Documentation/devicetree/bindings/net/can/tcan4x5x.txt b/Documentation/devicetree/bindings/net/can/tcan4x5x.txt
new file mode 100644
index 000000000000..c388f7d9feb1
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/can/tcan4x5x.txt
@@ -0,0 +1,37 @@
+Texas Instruments TCAN4x5x CAN Controller
+================================================
+
+This file provides device node information for the TCAN4x5x interface contains.
+
+Required properties:
+	- compatible: "ti,tcan4x5x"
+	- reg: 0
+	- #address-cells: 1
+	- #size-cells: 0
+	- spi-max-frequency: Maximum frequency of the SPI bus the chip can
+			     operate at should be less than or equal to 18 MHz.
+	- data-ready-gpios: Interrupt GPIO for data and error reporting.
+	- device-wake-gpios: Wake up GPIO to wake up the TCAN device.
+
+See Documentation/devicetree/bindings/net/can/m_can.txt for additional
+required property details.
+
+Optional properties:
+	- reset-gpios: Hardwired output GPIO. If not defined then software
+		       reset.
+	- device-state-gpios: Input GPIO that indicates if the device is in
+			      a sleep state or if the device is active.
+
+Example:
+tcan4x5x: tcan4x5x@0 {
+		compatible = "ti,tcan4x5x";
+		reg = <0>;
+		#address-cells = <1>;
+		#size-cells = <1>;
+		spi-max-frequency = <10000000>;
+		bosch,mram-cfg = <0x0 0 0 32 0 0 1 1>;
+		data-ready-gpios = <&gpio1 14 GPIO_ACTIVE_LOW>;
+		device-state-gpios = <&gpio3 21 GPIO_ACTIVE_HIGH>;
+		device-wake-gpios = <&gpio1 15 GPIO_ACTIVE_HIGH>;
+		reset-gpios = <&gpio1 27 GPIO_ACTIVE_LOW>;
+};
-- 
2.20.1.390.gb5101f9297


^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v7 4/4] can: tcan4x5x: Add tcan4x5x driver to the kernel
  2019-03-05 15:52 [PATCH v7 1/4] can: m_can: Create a m_can platform framework Dan Murphy
  2019-03-05 15:52 ` [PATCH v7 2/4] can: m_can: Rename m_can_priv to m_can_classdev Dan Murphy
  2019-03-05 15:52 ` [PATCH v7 3/4] dt-bindings: can: tcan4x5x: Add DT bindings for TCAN4x5X driver Dan Murphy
@ 2019-03-05 15:52 ` Dan Murphy
  2019-03-08 10:10 ` [PATCH v7 1/4] can: m_can: Create a m_can platform framework Wolfgang Grandegger
  3 siblings, 0 replies; 18+ messages in thread
From: Dan Murphy @ 2019-03-05 15:52 UTC (permalink / raw)
  To: wg, mkl, davem; +Cc: linux-can, netdev, linux-kernel, Dan Murphy

Add the TCAN4x5x SPI CAN driver.  This device uses the
Bosch MCAN IP core along with a SPI interface map.
Register to the MCAN common core code to manage the MCAN IP.

This device has a special method to indicate a write/read
operation on the data payload.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
---

v7 - Fixed remaining checkpatch issues and renamed callbacks for m_can change -
https://lore.kernel.org/patchwork/patch/1047221/

v6 - Updated Kconfig help and added REGMAP_SPI dependency, fixed coding style issues,
removed setting GPIO high in wake routine, change -EIO to return ret in init and
setup functions - https://lore.kernel.org/patchwork/patch/1042443/

 drivers/net/can/m_can/Kconfig    |   9 +
 drivers/net/can/m_can/Makefile   |   1 +
 drivers/net/can/m_can/tcan4x5x.c | 533 +++++++++++++++++++++++++++++++
 3 files changed, 543 insertions(+)
 create mode 100644 drivers/net/can/m_can/tcan4x5x.c

diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
index f7119fd72df4..cf4f32765efa 100644
--- a/drivers/net/can/m_can/Kconfig
+++ b/drivers/net/can/m_can/Kconfig
@@ -12,3 +12,12 @@ config CAN_M_CAN_PLATFORM
 	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
 	  This support is for devices that have the Bosch M_CAN controller
 	  IP embedded into the device and the IP is IO Mapped to the processor.
+
+config CAN_M_CAN_TCAN4X5X
+	depends on CAN_M_CAN
+	depends on REGMAP_SPI
+	tristate "TCAN4X5X M_CAN device"
+	---help---
+	  Say Y here if you want support for Texas Instruments TCAN4x5x
+	  M_CAN controller.  This device is a peripherial device that uses the
+	  SPI bus for communication.
diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
index 057bbcdb3c74..e77f0eccff97 100644
--- a/drivers/net/can/m_can/Makefile
+++ b/drivers/net/can/m_can/Makefile
@@ -4,3 +4,4 @@
 
 obj-$(CONFIG_CAN_M_CAN) += m_can.o
 obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
+obj-$(CONFIG_CAN_M_CAN_TCAN4X5X) += tcan4x5x.o
diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c
new file mode 100644
index 000000000000..9f52b298fdbf
--- /dev/null
+++ b/drivers/net/can/m_can/tcan4x5x.c
@@ -0,0 +1,533 @@
+// SPDX-License-Identifier: GPL-2.0
+// SPI to CAN driver for the Texas Instruments TCAN4x5x
+// Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
+
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include <linux/regulator/consumer.h>
+#include <linux/gpio/consumer.h>
+
+#include "m_can.h"
+
+#define DEVICE_NAME "tcan4x5x"
+#define TCAN4X5X_EXT_CLK_DEF	40000000
+
+#define TCAN4X5X_DEV_ID0	0x00
+#define TCAN4X5X_DEV_ID1	0x04
+#define TCAN4X5X_REV		0x08
+#define TCAN4X5X_STATUS		0x0C
+#define TCAN4X5X_ERROR_STATUS	0x10
+#define TCAN4X5X_CONTROL	0x14
+
+#define TCAN4X5X_CONFIG		0x800
+#define TCAN4X5X_TS_PRESCALE	0x804
+#define TCAN4X5X_TEST_REG	0x808
+#define TCAN4X5X_INT_FLAGS	0x820
+#define TCAN4X5X_MCAN_INT_REG	0x824
+#define TCAN4X5X_INT_EN		0x830
+
+/* Interrupt bits */
+#define TCAN4X5X_CANBUSTERMOPEN_INT_EN	BIT(30)
+#define TCAN4X5X_CANHCANL_INT_EN	BIT(29)
+#define TCAN4X5X_CANHBAT_INT_EN		BIT(28)
+#define TCAN4X5X_CANLGND_INT_EN		BIT(27)
+#define TCAN4X5X_CANBUSOPEN_INT_EN	BIT(26)
+#define TCAN4X5X_CANBUSGND_INT_EN	BIT(25)
+#define TCAN4X5X_CANBUSBAT_INT_EN	BIT(24)
+#define TCAN4X5X_UVSUP_INT_EN		BIT(22)
+#define TCAN4X5X_UVIO_INT_EN		BIT(21)
+#define TCAN4X5X_TSD_INT_EN		BIT(19)
+#define TCAN4X5X_ECCERR_INT_EN		BIT(16)
+#define TCAN4X5X_CANINT_INT_EN		BIT(15)
+#define TCAN4X5X_LWU_INT_EN		BIT(14)
+#define TCAN4X5X_CANSLNT_INT_EN		BIT(10)
+#define TCAN4X5X_CANDOM_INT_EN		BIT(8)
+#define TCAN4X5X_CANBUS_ERR_INT_EN	BIT(5)
+#define TCAN4X5X_BUS_FAULT		BIT(4)
+#define TCAN4X5X_MCAN_INT		BIT(1)
+#define TCAN4X5X_ENABLE_TCAN_INT	(TCAN4X5X_MCAN_INT | \
+					TCAN4X5X_BUS_FAULT | \
+					TCAN4X5X_CANBUS_ERR_INT_EN | \
+					TCAN4X5X_CANINT_INT_EN)
+
+/* MCAN Interrupt bits */
+#define TCAN4X5X_MCAN_IR_ARA		BIT(29)
+#define TCAN4X5X_MCAN_IR_PED		BIT(28)
+#define TCAN4X5X_MCAN_IR_PEA		BIT(27)
+#define TCAN4X5X_MCAN_IR_WD		BIT(26)
+#define TCAN4X5X_MCAN_IR_BO		BIT(25)
+#define TCAN4X5X_MCAN_IR_EW		BIT(24)
+#define TCAN4X5X_MCAN_IR_EP		BIT(23)
+#define TCAN4X5X_MCAN_IR_ELO		BIT(22)
+#define TCAN4X5X_MCAN_IR_BEU		BIT(21)
+#define TCAN4X5X_MCAN_IR_BEC		BIT(20)
+#define TCAN4X5X_MCAN_IR_DRX		BIT(19)
+#define TCAN4X5X_MCAN_IR_TOO		BIT(18)
+#define TCAN4X5X_MCAN_IR_MRAF		BIT(17)
+#define TCAN4X5X_MCAN_IR_TSW		BIT(16)
+#define TCAN4X5X_MCAN_IR_TEFL		BIT(15)
+#define TCAN4X5X_MCAN_IR_TEFF		BIT(14)
+#define TCAN4X5X_MCAN_IR_TEFW		BIT(13)
+#define TCAN4X5X_MCAN_IR_TEFN		BIT(12)
+#define TCAN4X5X_MCAN_IR_TFE		BIT(11)
+#define TCAN4X5X_MCAN_IR_TCF		BIT(10)
+#define TCAN4X5X_MCAN_IR_TC		BIT(9)
+#define TCAN4X5X_MCAN_IR_HPM		BIT(8)
+#define TCAN4X5X_MCAN_IR_RF1L		BIT(7)
+#define TCAN4X5X_MCAN_IR_RF1F		BIT(6)
+#define TCAN4X5X_MCAN_IR_RF1W		BIT(5)
+#define TCAN4X5X_MCAN_IR_RF1N		BIT(4)
+#define TCAN4X5X_MCAN_IR_RF0L		BIT(3)
+#define TCAN4X5X_MCAN_IR_RF0F		BIT(2)
+#define TCAN4X5X_MCAN_IR_RF0W		BIT(1)
+#define TCAN4X5X_MCAN_IR_RF0N		BIT(0)
+#define TCAN4X5X_ENABLE_MCAN_INT	(TCAN4X5X_MCAN_IR_TC | \
+					TCAN4X5X_MCAN_IR_RF0N | \
+					TCAN4X5X_MCAN_IR_RF1N | \
+					TCAN4X5X_MCAN_IR_RF0F | \
+					TCAN4X5X_MCAN_IR_RF1F)
+#define TCAN4X5X_MRAM_START	0x8000
+#define TCAN4X5X_MCAN_OFFSET	0x1000
+#define TCAN4X5X_MAX_REGISTER	0x8fff
+
+#define TCAN4X5X_CLEAR_ALL_INT	0xffffffff
+#define TCAN4X5X_SET_ALL_INT	0xffffffff
+
+#define TCAN4X5X_WRITE_CMD	(0x61 << 24)
+#define TCAN4X5X_READ_CMD	(0x41 << 24)
+
+#define TCAN4X5X_MODE_SEL_MASK		(BIT(7) | BIT(6))
+#define TCAN4X5X_MODE_SLEEP		0x00
+#define TCAN4X5X_MODE_STANDBY		BIT(6)
+#define TCAN4X5X_MODE_NORMAL		BIT(7)
+
+#define TCAN4X5X_SW_RESET	BIT(2)
+
+#define TCAN4X5X_MCAN_CONFIGURED	BIT(5)
+#define TCAN4X5X_WATCHDOG_EN		BIT(3)
+#define TCAN4X5X_WD_60_MS_TIMER		0
+#define TCAN4X5X_WD_600_MS_TIMER	BIT(28)
+#define TCAN4X5X_WD_3_S_TIMER		BIT(29)
+#define TCAN4X5X_WD_6_S_TIMER		(BIT(28) | BIT(29))
+
+struct tcan4x5x_priv {
+	struct regmap *regmap;
+	struct spi_device *spi;
+	struct mutex tcan4x5x_lock; /* SPI device lock */
+
+	struct m_can_classdev *mcan_dev;
+
+	struct gpio_desc *reset_gpio;
+	struct gpio_desc *interrupt_gpio;
+	struct gpio_desc *device_wake_gpio;
+	struct gpio_desc *device_state_gpio;
+	struct regulator *power;
+
+	/* Register based ip */
+	int mram_start;
+	int reg_offset;
+};
+
+static struct can_bittiming_const tcan4x5x_bittiming_const = {
+	.name = DEVICE_NAME,
+	.tseg1_min = 2,
+	.tseg1_max = 31,
+	.tseg2_min = 2,
+	.tseg2_max = 16,
+	.sjw_max = 16,
+	.brp_min = 1,
+	.brp_max = 32,
+	.brp_inc = 1,
+};
+
+static struct can_bittiming_const tcan4x5x_data_bittiming_const = {
+	.name = DEVICE_NAME,
+	.tseg1_min = 1,
+	.tseg1_max = 32,
+	.tseg2_min = 1,
+	.tseg2_max = 16,
+	.sjw_max = 16,
+	.brp_min = 1,
+	.brp_max = 32,
+	.brp_inc = 1,
+};
+
+static void tcan4x5x_check_wake(struct tcan4x5x_priv *priv)
+{
+	int wake_state = 0;
+
+	if (priv->device_state_gpio)
+		wake_state = gpiod_get_value(priv->device_state_gpio);
+
+	if (priv->device_wake_gpio && wake_state) {
+		gpiod_set_value(priv->device_wake_gpio, 0);
+		usleep_range(5, 50);
+		gpiod_set_value(priv->device_wake_gpio, 1);
+	}
+}
+
+static int regmap_spi_gather_write(void *context, const void *reg,
+				   size_t reg_len, const void *val,
+				   size_t val_len)
+{
+	struct device *dev = context;
+	struct spi_device *spi = to_spi_device(dev);
+	struct spi_message m;
+	u32 addr;
+	struct spi_transfer t[2] = {
+		{ .tx_buf = &addr, .len = reg_len, .cs_change = 0,},
+		{ .tx_buf = val, .len = val_len, },
+	};
+
+	addr = TCAN4X5X_WRITE_CMD | (*((u16 *)reg) << 8) | val_len >> 3;
+
+	spi_message_init(&m);
+	spi_message_add_tail(&t[0], &m);
+	spi_message_add_tail(&t[1], &m);
+
+	return spi_sync(spi, &m);
+}
+
+static int tcan4x5x_regmap_write(void *context, const void *data, size_t count)
+{
+	u16 *reg = (u16 *)(data);
+	const u32 *val = data + 4;
+
+	return regmap_spi_gather_write(context, reg, 4, val, count);
+}
+
+static int regmap_spi_async_write(void *context,
+				  const void *reg, size_t reg_len,
+				  const void *val, size_t val_len,
+				  struct regmap_async *a)
+{
+	return -ENOTSUPP;
+}
+
+static struct regmap_async *regmap_spi_async_alloc(void)
+{
+	return NULL;
+}
+
+static int tcan4x5x_regmap_read(void *context,
+				const void *reg, size_t reg_size,
+				void *val, size_t val_size)
+{
+	struct device *dev = context;
+	struct spi_device *spi = to_spi_device(dev);
+
+	u32 addr = TCAN4X5X_READ_CMD | (*((u16 *)reg) << 8) | val_size >> 2;
+
+	return spi_write_then_read(spi, &addr, reg_size, (u32 *)val, val_size);
+}
+
+static struct regmap_bus tcan4x5x_bus = {
+	.write = tcan4x5x_regmap_write,
+	.gather_write = regmap_spi_gather_write,
+	.async_write = regmap_spi_async_write,
+	.async_alloc = regmap_spi_async_alloc,
+	.read = tcan4x5x_regmap_read,
+	.read_flag_mask = 0x00,
+	.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
+	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
+};
+
+static u32 tcan4x5x_read_reg(struct m_can_classdev *cdev, int reg)
+{
+	struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)cdev->device_data;
+	u32 val;
+
+	tcan4x5x_check_wake(priv);
+
+	regmap_read(priv->regmap, priv->reg_offset + reg, &val);
+
+	return val;
+}
+
+static u32 tcan4x5x_read_fifo(struct m_can_classdev *cdev, int addr_offset)
+{
+	struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)cdev->device_data;
+	u32 val;
+
+	tcan4x5x_check_wake(priv);
+
+	regmap_read(priv->regmap, priv->mram_start + addr_offset, &val);
+
+	return val;
+}
+
+static int tcan4x5x_write_reg(struct m_can_classdev *cdev, int reg, int val)
+{
+	struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)cdev->device_data;
+
+	tcan4x5x_check_wake(priv);
+
+	return regmap_write(priv->regmap, priv->reg_offset + reg, val);
+}
+
+static int tcan4x5x_write_fifo(struct m_can_classdev *cdev,
+			       int addr_offset, int val)
+{
+	struct tcan4x5x_priv *priv =
+			(struct tcan4x5x_priv *)cdev->device_data;
+
+	tcan4x5x_check_wake(priv);
+
+	return regmap_write(priv->regmap, priv->mram_start + addr_offset, val);
+}
+
+static int tcan4x5x_power_enable(struct regulator *reg, int enable)
+{
+	if (IS_ERR_OR_NULL(reg))
+		return 0;
+
+	if (enable)
+		return regulator_enable(reg);
+	else
+		return regulator_disable(reg);
+}
+
+static int tcan4x5x_write_tcan_reg(struct m_can_classdev *cdev,
+				   int reg, int val)
+{
+	struct tcan4x5x_priv *priv =
+			(struct tcan4x5x_priv *)cdev->device_data;
+
+	tcan4x5x_check_wake(priv);
+
+	return regmap_write(priv->regmap, reg, val);
+}
+
+static int tcan4x5x_clear_interrupts(struct m_can_classdev *cdev)
+{
+	struct tcan4x5x_priv *tcan4x5x =
+				(struct tcan4x5x_priv *)cdev->device_data;
+	int ret;
+
+	tcan4x5x_check_wake(tcan4x5x);
+
+	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_STATUS,
+				      TCAN4X5X_CLEAR_ALL_INT);
+	if (ret)
+		return ret;
+
+	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_MCAN_INT_REG,
+				      TCAN4X5X_ENABLE_MCAN_INT);
+	if (ret)
+		return ret;
+
+	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_FLAGS,
+				      TCAN4X5X_CLEAR_ALL_INT);
+	if (ret)
+		return ret;
+
+	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_ERROR_STATUS,
+				      TCAN4X5X_CLEAR_ALL_INT);
+	if (ret)
+		return ret;
+
+	return ret;
+}
+
+static int tcan4x5x_init(struct m_can_classdev *cdev)
+{
+	struct tcan4x5x_priv *tcan4x5x =
+				(struct tcan4x5x_priv *)cdev->device_data;
+	int ret;
+
+	tcan4x5x_check_wake(tcan4x5x);
+
+	ret = tcan4x5x_clear_interrupts(cdev);
+	if (ret)
+		return ret;
+
+	ret = tcan4x5x_write_tcan_reg(cdev, TCAN4X5X_INT_EN,
+				      TCAN4X5X_ENABLE_TCAN_INT);
+	if (ret)
+		return ret;
+
+	ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
+				 TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL);
+	if (ret)
+		return ret;
+
+	/* Zero out the MCAN buffers */
+	m_can_init_ram(cdev);
+
+	return ret;
+}
+
+static int tcan4x5x_parse_config(struct m_can_classdev *cdev)
+{
+	struct tcan4x5x_priv *tcan4x5x =
+				(struct tcan4x5x_priv *)cdev->device_data;
+
+	tcan4x5x->interrupt_gpio = devm_gpiod_get(cdev->dev, "data-ready",
+						  GPIOD_IN);
+	if (IS_ERR(tcan4x5x->interrupt_gpio)) {
+		dev_err(cdev->dev, "data-ready gpio not defined\n");
+		return -EINVAL;
+	}
+
+	tcan4x5x->device_wake_gpio = devm_gpiod_get(cdev->dev, "device-wake",
+						    GPIOD_OUT_HIGH);
+	if (IS_ERR(tcan4x5x->device_wake_gpio)) {
+		dev_err(cdev->dev, "device-wake gpio not defined\n");
+		return -EINVAL;
+	}
+
+	tcan4x5x->reset_gpio = devm_gpiod_get_optional(cdev->dev, "reset",
+						       GPIOD_OUT_LOW);
+	if (IS_ERR(tcan4x5x->reset_gpio))
+		tcan4x5x->reset_gpio = NULL;
+
+	tcan4x5x->device_state_gpio = devm_gpiod_get_optional(cdev->dev,
+							      "device-state",
+							      GPIOD_IN);
+	if (IS_ERR(tcan4x5x->device_state_gpio))
+		tcan4x5x->device_state_gpio = NULL;
+
+	cdev->net->irq = gpiod_to_irq(tcan4x5x->interrupt_gpio);
+
+	tcan4x5x->power = devm_regulator_get_optional(cdev->dev,
+						      "vsup");
+	if (PTR_ERR(tcan4x5x->power) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
+	return 0;
+}
+
+static const struct regmap_config tcan4x5x_regmap = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.cache_type = REGCACHE_NONE,
+	.max_register = TCAN4X5X_MAX_REGISTER,
+};
+
+static struct m_can_ops tcan4x5x_ops = {
+	.init = tcan4x5x_init,
+	.read_reg = tcan4x5x_read_reg,
+	.write_reg = tcan4x5x_write_reg,
+	.write_fifo = tcan4x5x_write_fifo,
+	.read_fifo = tcan4x5x_read_fifo,
+	.clear_interrupts = tcan4x5x_clear_interrupts,
+};
+
+static int tcan4x5x_can_probe(struct spi_device *spi)
+{
+	struct tcan4x5x_priv *priv;
+	struct m_can_classdev *mcan_class;
+	int freq, ret;
+
+	mcan_class = m_can_class_allocate_dev(&spi->dev);
+	priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	mcan_class->device_data = priv;
+
+	m_can_class_get_clocks(mcan_class);
+	if (IS_ERR(mcan_class->cclk)) {
+		dev_err(&spi->dev, "no CAN clock source defined\n");
+		freq = TCAN4X5X_EXT_CLK_DEF;
+	} else {
+		freq = clk_get_rate(mcan_class->cclk);
+	}
+
+	/* Sanity check */
+	if (freq < 20000000 || freq > TCAN4X5X_EXT_CLK_DEF)
+		return -ERANGE;
+
+	priv->reg_offset = TCAN4X5X_MCAN_OFFSET;
+	priv->mram_start = TCAN4X5X_MRAM_START;
+	priv->spi = spi;
+	priv->mcan_dev = mcan_class;
+
+	mcan_class->pm_clock_support = 0;
+	mcan_class->can.clock.freq = freq;
+	mcan_class->dev = &spi->dev;
+	mcan_class->ops = &tcan4x5x_ops;
+	mcan_class->is_peripherial = true;
+	mcan_class->bit_timing = &tcan4x5x_bittiming_const;
+	mcan_class->data_timing = &tcan4x5x_data_bittiming_const;
+
+	spi_set_drvdata(spi, priv);
+
+	ret = tcan4x5x_parse_config(mcan_class);
+	if (ret)
+		goto out_clk;
+
+	/* Configure the SPI bus */
+	spi->bits_per_word = 32;
+	ret = spi_setup(spi);
+	if (ret)
+		goto out_clk;
+
+	priv->regmap = devm_regmap_init(&spi->dev, &tcan4x5x_bus,
+					&spi->dev, &tcan4x5x_regmap);
+
+	mutex_init(&priv->tcan4x5x_lock);
+
+	tcan4x5x_power_enable(priv->power, 1);
+
+	ret = m_can_class_register(mcan_class);
+	if (ret)
+		goto out_power;
+
+	netdev_info(mcan_class->net, "TCAN4X5X successfully initialized.\n");
+	return 0;
+
+out_power:
+	tcan4x5x_power_enable(priv->power, 0);
+out_clk:
+	if (!IS_ERR(mcan_class->cclk)) {
+		clk_disable_unprepare(mcan_class->cclk);
+		clk_disable_unprepare(mcan_class->hclk);
+	}
+
+	dev_err(&spi->dev, "Probe failed, err=%d\n", ret);
+	return ret;
+}
+
+static int tcan4x5x_can_remove(struct spi_device *spi)
+{
+	struct tcan4x5x_priv *priv = spi_get_drvdata(spi);
+
+	tcan4x5x_power_enable(priv->power, 0);
+
+	m_can_class_unregister(priv->mcan_dev);
+
+	return 0;
+}
+
+static const struct of_device_id tcan4x5x_of_match[] = {
+	{ .compatible = "ti,tcan4x5x", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, tcan4x5x_of_match);
+
+static const struct spi_device_id tcan4x5x_id_table[] = {
+	{
+		.name		= "tcan4x5x",
+		.driver_data	= 0,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, tcan4x5x_id_table);
+
+static struct spi_driver tcan4x5x_can_driver = {
+	.driver = {
+		.name = DEVICE_NAME,
+		.of_match_table = tcan4x5x_of_match,
+		.pm = NULL,
+	},
+	.id_table = tcan4x5x_id_table,
+	.probe = tcan4x5x_can_probe,
+	.remove = tcan4x5x_can_remove,
+};
+module_spi_driver(tcan4x5x_can_driver);
+
+MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
+MODULE_DESCRIPTION("Texas Instruments TCAN4x5x CAN driver");
+MODULE_LICENSE("GPL v2");
-- 
2.20.1.390.gb5101f9297


^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 1/4] can: m_can: Create a m_can platform framework
  2019-03-05 15:52 [PATCH v7 1/4] can: m_can: Create a m_can platform framework Dan Murphy
                   ` (2 preceding siblings ...)
  2019-03-05 15:52 ` [PATCH v7 4/4] can: tcan4x5x: Add tcan4x5x driver to the kernel Dan Murphy
@ 2019-03-08 10:10 ` Wolfgang Grandegger
  2019-03-08 12:44   ` Dan Murphy
  3 siblings, 1 reply; 18+ messages in thread
From: Wolfgang Grandegger @ 2019-03-08 10:10 UTC (permalink / raw)
  To: Dan Murphy, mkl, davem; +Cc: linux-can, netdev, linux-kernel

Hallo Dan,

Am 05.03.19 um 16:52 schrieb Dan Murphy:
> Create a m_can platform framework that peripherial
> devices can register to and use common code and register sets.
> The peripherial devices may provide read/write and configuration
> support of the IP.
> 
> Signed-off-by: Dan Murphy <dmurphy@ti.com>
> ---
> 
> 
> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
> start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/
> 
> v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
> issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/
> 
>  drivers/net/can/m_can/Kconfig          |  13 +-
>  drivers/net/can/m_can/Makefile         |   1 +
>  drivers/net/can/m_can/m_can.c          | 700 +++++++++++++------------
>  drivers/net/can/m_can/m_can.h          | 110 ++++
>  drivers/net/can/m_can/m_can_platform.c | 202 +++++++
>  5 files changed, 682 insertions(+), 344 deletions(-)
>  create mode 100644 drivers/net/can/m_can/m_can.h
>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
> 
> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
> index 04f20dd39007..f7119fd72df4 100644
> --- a/drivers/net/can/m_can/Kconfig
> +++ b/drivers/net/can/m_can/Kconfig
> @@ -1,5 +1,14 @@
>  config CAN_M_CAN
> +	tristate "Bosch M_CAN support"
> +	---help---
> +	  Say Y here if you want support for Bosch M_CAN controller framework.
> +	  This is common support for devices that embed the Bosch M_CAN IP.
> +
> +config CAN_M_CAN_PLATFORM
> +	tristate "Bosch M_CAN support for io-mapped devices"
>  	depends on HAS_IOMEM
> -	tristate "Bosch M_CAN devices"
> +	depends on CAN_M_CAN
>  	---help---
> -	  Say Y here if you want to support for Bosch M_CAN controller.
> +	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
> +	  This support is for devices that have the Bosch M_CAN controller
> +	  IP embedded into the device and the IP is IO Mapped to the processor.
> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
> index 8bbd7f24f5be..057bbcdb3c74 100644
> --- a/drivers/net/can/m_can/Makefile
> +++ b/drivers/net/can/m_can/Makefile
> @@ -3,3 +3,4 @@
>  #
>  
>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
> index 9b449400376b..a60278d94126 100644
> --- a/drivers/net/can/m_can/m_can.c
> +++ b/drivers/net/can/m_can/m_can.c

... snip...

> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
> +				    struct net_device *dev)
> +{
> +	struct m_can_priv *priv = netdev_priv(dev);
> +
> +	if (can_dropped_invalid_skb(dev, skb))
> +		return NETDEV_TX_OK;
> +
> +	if (priv->is_peripherial) {
> +		if (priv->tx_skb) {
> +			netdev_err(dev, "hard_xmit called while tx busy\n");
> +			return NETDEV_TX_BUSY;
> +		}

The problem with that approach is, that the upper layer will try to
resubmit the current "skb" but not the previous "tx_skb". And the
previous "tx_skb" has not been freed yet. I would just drop and free the
skb and return NETDEV_TX_OK in m_can_tx_handler() for peripheral devices
(like can_dropped_invalid_skb() does).

> +
> +		priv->tx_skb = skb;
> +		netif_stop_queue(priv->net);
> +		queue_work(priv->tx_wq, &priv->tx_work);
> +	} else {
> +		priv->tx_skb = skb;
> +		return m_can_tx_handler(priv);
>  	}
>  
>  	return NETDEV_TX_OK;
>  }

Wolfgang.


^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 2/4] can: m_can: Rename m_can_priv to m_can_classdev
  2019-03-05 15:52 ` [PATCH v7 2/4] can: m_can: Rename m_can_priv to m_can_classdev Dan Murphy
@ 2019-03-08 10:25   ` Wolfgang Grandegger
  2019-03-08 12:33     ` Dan Murphy
  0 siblings, 1 reply; 18+ messages in thread
From: Wolfgang Grandegger @ 2019-03-08 10:25 UTC (permalink / raw)
  To: Dan Murphy, mkl, davem; +Cc: linux-can, netdev, linux-kernel



Am 05.03.19 um 16:52 schrieb Dan Murphy:
> Rename the common m_can_priv class structure to
> m_can_classdev as this is more descriptive.
> 
> Signed-off-by: Dan Murphy <dmurphy@ti.com>
> ---
> 
> v7 - Fixed remaining checkpatch issues, renamed priv to cdev - https://lore.kernel.org/patchwork/patch/1047219/
> 
> v6 - No changes only rebase changes possibly can squash into the first patch - 
> https://lore.kernel.org/patchwork/patch/1042444/
> 
>  drivers/net/can/m_can/m_can.c          | 524 ++++++++++++-------------
>  drivers/net/can/m_can/m_can.h          |  28 +-
>  drivers/net/can/m_can/m_can_platform.c |  16 +-
>  3 files changed, 284 insertions(+), 284 deletions(-)

...snip...

> diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h
> index b60f27dd9f33..1299cc747194 100644
> --- a/drivers/net/can/m_can/m_can.h
> +++ b/drivers/net/can/m_can/m_can.h
> @@ -57,19 +57,19 @@ struct mram_cfg {
>  	u8  num;
>  };
>  
> -struct m_can_priv;
> +struct m_can_classdev;
>  struct m_can_ops {
>  	/* Device specific call backs */
> -	int (*clear_interrupts)(struct m_can_priv *m_can_class);
> -	u32 (*read_reg)(struct m_can_priv *m_can_class, int reg);
> -	int (*write_reg)(struct m_can_priv *m_can_class, int reg, int val);
> -	u32 (*read_fifo)(struct m_can_priv *m_can_class, int addr_offset);
> -	int (*write_fifo)(struct m_can_priv *m_can_class, int addr_offset,
> +	int (*clear_interrupts)(struct m_can_classdev *m_can_class);
> +	u32 (*read_reg)(struct m_can_classdev *m_can_class, int reg);
> +	int (*write_reg)(struct m_can_classdev *m_can_class, int reg, int val);
> +	u32 (*read_fifo)(struct m_can_classdev *m_can_class, int addr_offset);
> +	int (*write_fifo)(struct m_can_classdev *m_can_class, int addr_offset,

Could you please replace the variable name "m_can_class" with "cdev"
here and below and in "c_can_platform.c " and "tcan4x5x.c" as well.

Thanks,

Wolfgang.


^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 2/4] can: m_can: Rename m_can_priv to m_can_classdev
  2019-03-08 10:25   ` Wolfgang Grandegger
@ 2019-03-08 12:33     ` Dan Murphy
  0 siblings, 0 replies; 18+ messages in thread
From: Dan Murphy @ 2019-03-08 12:33 UTC (permalink / raw)
  To: Wolfgang Grandegger, mkl, davem; +Cc: linux-can, netdev, linux-kernel

Wolfgang

On 3/8/19 4:25 AM, Wolfgang Grandegger wrote:
> 
> 
> Am 05.03.19 um 16:52 schrieb Dan Murphy:
>> Rename the common m_can_priv class structure to
>> m_can_classdev as this is more descriptive.
>>
>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>> ---
>>
>> v7 - Fixed remaining checkpatch issues, renamed priv to cdev - https://lore.kernel.org/patchwork/patch/1047219/
>>
>> v6 - No changes only rebase changes possibly can squash into the first patch - 
>> https://lore.kernel.org/patchwork/patch/1042444/
>>
>>  drivers/net/can/m_can/m_can.c          | 524 ++++++++++++-------------
>>  drivers/net/can/m_can/m_can.h          |  28 +-
>>  drivers/net/can/m_can/m_can_platform.c |  16 +-
>>  3 files changed, 284 insertions(+), 284 deletions(-)
> 
> ...snip...
> 
>> diff --git a/drivers/net/can/m_can/m_can.h b/drivers/net/can/m_can/m_can.h
>> index b60f27dd9f33..1299cc747194 100644
>> --- a/drivers/net/can/m_can/m_can.h
>> +++ b/drivers/net/can/m_can/m_can.h
>> @@ -57,19 +57,19 @@ struct mram_cfg {
>>  	u8  num;
>>  };
>>  
>> -struct m_can_priv;
>> +struct m_can_classdev;
>>  struct m_can_ops {
>>  	/* Device specific call backs */
>> -	int (*clear_interrupts)(struct m_can_priv *m_can_class);
>> -	u32 (*read_reg)(struct m_can_priv *m_can_class, int reg);
>> -	int (*write_reg)(struct m_can_priv *m_can_class, int reg, int val);
>> -	u32 (*read_fifo)(struct m_can_priv *m_can_class, int addr_offset);
>> -	int (*write_fifo)(struct m_can_priv *m_can_class, int addr_offset,
>> +	int (*clear_interrupts)(struct m_can_classdev *m_can_class);
>> +	u32 (*read_reg)(struct m_can_classdev *m_can_class, int reg);
>> +	int (*write_reg)(struct m_can_classdev *m_can_class, int reg, int val);
>> +	u32 (*read_fifo)(struct m_can_classdev *m_can_class, int addr_offset);
>> +	int (*write_fifo)(struct m_can_classdev *m_can_class, int addr_offset,
> 
> Could you please replace the variable name "m_can_class" with "cdev"
> here and below and in "c_can_platform.c " and "tcan4x5x.c" as well.
> 

OK I will update the header

The tcan and m_can_platform source files are converted to cdev as opposed to m_can_class variable.

Dan

> Thanks,
> 
> Wolfgang.
> 


-- 
------------------
Dan Murphy

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 1/4] can: m_can: Create a m_can platform framework
  2019-03-08 10:10 ` [PATCH v7 1/4] can: m_can: Create a m_can platform framework Wolfgang Grandegger
@ 2019-03-08 12:44   ` Dan Murphy
  2019-03-08 13:29     ` Wolfgang Grandegger
  0 siblings, 1 reply; 18+ messages in thread
From: Dan Murphy @ 2019-03-08 12:44 UTC (permalink / raw)
  To: Wolfgang Grandegger, mkl, davem; +Cc: linux-can, netdev, linux-kernel

Wolfgang

On 3/8/19 4:10 AM, Wolfgang Grandegger wrote:
> Hallo Dan,
> 
> Am 05.03.19 um 16:52 schrieb Dan Murphy:
>> Create a m_can platform framework that peripherial
>> devices can register to and use common code and register sets.
>> The peripherial devices may provide read/write and configuration
>> support of the IP.
>>
>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>> ---
>>
>>
>> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
>> start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/
>>
>> v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
>> issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
>> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
>> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
>> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/
>>
>>  drivers/net/can/m_can/Kconfig          |  13 +-
>>  drivers/net/can/m_can/Makefile         |   1 +
>>  drivers/net/can/m_can/m_can.c          | 700 +++++++++++++------------
>>  drivers/net/can/m_can/m_can.h          | 110 ++++
>>  drivers/net/can/m_can/m_can_platform.c | 202 +++++++
>>  5 files changed, 682 insertions(+), 344 deletions(-)
>>  create mode 100644 drivers/net/can/m_can/m_can.h
>>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
>>
>> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
>> index 04f20dd39007..f7119fd72df4 100644
>> --- a/drivers/net/can/m_can/Kconfig
>> +++ b/drivers/net/can/m_can/Kconfig
>> @@ -1,5 +1,14 @@
>>  config CAN_M_CAN
>> +	tristate "Bosch M_CAN support"
>> +	---help---
>> +	  Say Y here if you want support for Bosch M_CAN controller framework.
>> +	  This is common support for devices that embed the Bosch M_CAN IP.
>> +
>> +config CAN_M_CAN_PLATFORM
>> +	tristate "Bosch M_CAN support for io-mapped devices"
>>  	depends on HAS_IOMEM
>> -	tristate "Bosch M_CAN devices"
>> +	depends on CAN_M_CAN
>>  	---help---
>> -	  Say Y here if you want to support for Bosch M_CAN controller.
>> +	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>> +	  This support is for devices that have the Bosch M_CAN controller
>> +	  IP embedded into the device and the IP is IO Mapped to the processor.
>> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
>> index 8bbd7f24f5be..057bbcdb3c74 100644
>> --- a/drivers/net/can/m_can/Makefile
>> +++ b/drivers/net/can/m_can/Makefile
>> @@ -3,3 +3,4 @@
>>  #
>>  
>>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
>> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
>> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
>> index 9b449400376b..a60278d94126 100644
>> --- a/drivers/net/can/m_can/m_can.c
>> +++ b/drivers/net/can/m_can/m_can.c
> 
> ... snip...
> 
>> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>> +				    struct net_device *dev)
>> +{
>> +	struct m_can_priv *priv = netdev_priv(dev);
>> +
>> +	if (can_dropped_invalid_skb(dev, skb))
>> +		return NETDEV_TX_OK;
>> +
>> +	if (priv->is_peripherial) {
>> +		if (priv->tx_skb) {
>> +			netdev_err(dev, "hard_xmit called while tx busy\n");
>> +			return NETDEV_TX_BUSY;
>> +		}
> 
> The problem with that approach is, that the upper layer will try to
> resubmit the current "skb" but not the previous "tx_skb". And the
> previous "tx_skb" has not been freed yet. I would just drop and free the
> skb and return NETDEV_TX_OK in m_can_tx_handler() for peripheral devices
> (like can_dropped_invalid_skb() does).
> 

OK.

So would this also be a bug in the hi3110 and mcp251x drivers (line 521) as well because besides checking tx_length
this is how these drivers are written.

In addition in the peripheral context the work queue does not report up to the upper layer the status.
Again the hi3110 and mcp251x drivers are written this way.

The only issue I see here is that the dropped and invalid check needs to come after the tx_skb check.

Dan


>> +
>> +		priv->tx_skb = skb;
>> +		netif_stop_queue(priv->net);
>> +		queue_work(priv->tx_wq, &priv->tx_work);
>> +	} else {
>> +		priv->tx_skb = skb;
>> +		return m_can_tx_handler(priv);
>>  	}
>>  
>>  	return NETDEV_TX_OK;
>>  }
> 
> Wolfgang.
> 


-- 
------------------
Dan Murphy

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 1/4] can: m_can: Create a m_can platform framework
  2019-03-08 12:44   ` Dan Murphy
@ 2019-03-08 13:29     ` Wolfgang Grandegger
  2019-03-08 14:41       ` Wolfgang Grandegger
  0 siblings, 1 reply; 18+ messages in thread
From: Wolfgang Grandegger @ 2019-03-08 13:29 UTC (permalink / raw)
  To: Dan Murphy, mkl, davem; +Cc: linux-can, netdev, linux-kernel

Hello Dan,

Am 08.03.19 um 13:44 schrieb Dan Murphy:
> Wolfgang
> 
> On 3/8/19 4:10 AM, Wolfgang Grandegger wrote:
>> Hallo Dan,
>>
>> Am 05.03.19 um 16:52 schrieb Dan Murphy:
>>> Create a m_can platform framework that peripherial
>>> devices can register to and use common code and register sets.
>>> The peripherial devices may provide read/write and configuration
>>> support of the IP.
>>>
>>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>>> ---
>>>
>>>
>>> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
>>> start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/
>>>
>>> v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
>>> issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
>>> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
>>> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
>>> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/
>>>
>>>  drivers/net/can/m_can/Kconfig          |  13 +-
>>>  drivers/net/can/m_can/Makefile         |   1 +
>>>  drivers/net/can/m_can/m_can.c          | 700 +++++++++++++------------
>>>  drivers/net/can/m_can/m_can.h          | 110 ++++
>>>  drivers/net/can/m_can/m_can_platform.c | 202 +++++++
>>>  5 files changed, 682 insertions(+), 344 deletions(-)
>>>  create mode 100644 drivers/net/can/m_can/m_can.h
>>>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
>>>
>>> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
>>> index 04f20dd39007..f7119fd72df4 100644
>>> --- a/drivers/net/can/m_can/Kconfig
>>> +++ b/drivers/net/can/m_can/Kconfig
>>> @@ -1,5 +1,14 @@
>>>  config CAN_M_CAN
>>> +	tristate "Bosch M_CAN support"
>>> +	---help---
>>> +	  Say Y here if you want support for Bosch M_CAN controller framework.
>>> +	  This is common support for devices that embed the Bosch M_CAN IP.
>>> +
>>> +config CAN_M_CAN_PLATFORM
>>> +	tristate "Bosch M_CAN support for io-mapped devices"
>>>  	depends on HAS_IOMEM
>>> -	tristate "Bosch M_CAN devices"
>>> +	depends on CAN_M_CAN
>>>  	---help---
>>> -	  Say Y here if you want to support for Bosch M_CAN controller.
>>> +	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>>> +	  This support is for devices that have the Bosch M_CAN controller
>>> +	  IP embedded into the device and the IP is IO Mapped to the processor.
>>> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
>>> index 8bbd7f24f5be..057bbcdb3c74 100644
>>> --- a/drivers/net/can/m_can/Makefile
>>> +++ b/drivers/net/can/m_can/Makefile
>>> @@ -3,3 +3,4 @@
>>>  #
>>>  
>>>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
>>> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
>>> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
>>> index 9b449400376b..a60278d94126 100644
>>> --- a/drivers/net/can/m_can/m_can.c
>>> +++ b/drivers/net/can/m_can/m_can.c
>>
>> ... snip...
>>
>>> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>>> +				    struct net_device *dev)
>>> +{
>>> +	struct m_can_priv *priv = netdev_priv(dev);
>>> +
>>> +	if (can_dropped_invalid_skb(dev, skb))
>>> +		return NETDEV_TX_OK;
>>> +
>>> +	if (priv->is_peripherial) {
>>> +		if (priv->tx_skb) {
>>> +			netdev_err(dev, "hard_xmit called while tx busy\n");
>>> +			return NETDEV_TX_BUSY;
>>> +		}
>>
>> The problem with that approach is, that the upper layer will try to
>> resubmit the current "skb" but not the previous "tx_skb". And the
>> previous "tx_skb" has not been freed yet. I would just drop and free the
>> skb and return NETDEV_TX_OK in m_can_tx_handler() for peripheral devices
>> (like can_dropped_invalid_skb() does).
>>
> 
> OK.
> 
> So would this also be a bug in the hi3110 and mcp251x drivers (line 521) as well because besides checking tx_length
> this is how these drivers are written.

This is different. When entering the "start_xmit" routine, the previous
TX is still in progress. It will (hopefully) complete soon. Therefore
returning NETDEV_TX_BUSY is OK. The "start_xmit" routine will be
recalled soon with the same "skb". That scenario should/could also not
happen.

In contrast, in "m_can_tx_handler()", the skb could not be handled
because the FIFO is full. The "start_xmit" routine for peripheral
devices for that skb already returned NETDEV_TX_OK. Therefore the only
meaningful action is to drop the skb. Also this error should not happen
and if, something is going really wrong. Therefore I think, a
WARN_ONCE() would be even more appropriate. But that should be a
separate patch.

> 
> In addition in the peripheral context the work queue does not report up to the upper layer the status.
> Again the hi3110 and mcp251x drivers are written this way.
> 
> The only issue I see here is that the dropped and invalid check needs to come after the tx_skb check.

See above.

Wolfgang.

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 1/4] can: m_can: Create a m_can platform framework
  2019-03-08 13:29     ` Wolfgang Grandegger
@ 2019-03-08 14:41       ` Wolfgang Grandegger
  2019-03-08 15:48         ` Dan Murphy
  0 siblings, 1 reply; 18+ messages in thread
From: Wolfgang Grandegger @ 2019-03-08 14:41 UTC (permalink / raw)
  To: Dan Murphy, mkl, davem; +Cc: linux-can, netdev, linux-kernel

Hello Dan,

thinking more about it...

Am 08.03.19 um 14:29 schrieb Wolfgang Grandegger:
> Hello Dan,
> 
> Am 08.03.19 um 13:44 schrieb Dan Murphy:
>> Wolfgang
>>
>> On 3/8/19 4:10 AM, Wolfgang Grandegger wrote:
>>> Hallo Dan,
>>>
>>> Am 05.03.19 um 16:52 schrieb Dan Murphy:
>>>> Create a m_can platform framework that peripherial
>>>> devices can register to and use common code and register sets.
>>>> The peripherial devices may provide read/write and configuration
>>>> support of the IP.
>>>>
>>>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>>>> ---
>>>>
>>>>
>>>> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
>>>> start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/
>>>>
>>>> v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
>>>> issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
>>>> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
>>>> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
>>>> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/
>>>>
>>>>  drivers/net/can/m_can/Kconfig          |  13 +-
>>>>  drivers/net/can/m_can/Makefile         |   1 +
>>>>  drivers/net/can/m_can/m_can.c          | 700 +++++++++++++------------
>>>>  drivers/net/can/m_can/m_can.h          | 110 ++++
>>>>  drivers/net/can/m_can/m_can_platform.c | 202 +++++++
>>>>  5 files changed, 682 insertions(+), 344 deletions(-)
>>>>  create mode 100644 drivers/net/can/m_can/m_can.h
>>>>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
>>>>
>>>> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
>>>> index 04f20dd39007..f7119fd72df4 100644
>>>> --- a/drivers/net/can/m_can/Kconfig
>>>> +++ b/drivers/net/can/m_can/Kconfig
>>>> @@ -1,5 +1,14 @@
>>>>  config CAN_M_CAN
>>>> +	tristate "Bosch M_CAN support"
>>>> +	---help---
>>>> +	  Say Y here if you want support for Bosch M_CAN controller framework.
>>>> +	  This is common support for devices that embed the Bosch M_CAN IP.
>>>> +
>>>> +config CAN_M_CAN_PLATFORM
>>>> +	tristate "Bosch M_CAN support for io-mapped devices"
>>>>  	depends on HAS_IOMEM
>>>> -	tristate "Bosch M_CAN devices"
>>>> +	depends on CAN_M_CAN
>>>>  	---help---
>>>> -	  Say Y here if you want to support for Bosch M_CAN controller.
>>>> +	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>>>> +	  This support is for devices that have the Bosch M_CAN controller
>>>> +	  IP embedded into the device and the IP is IO Mapped to the processor.
>>>> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
>>>> index 8bbd7f24f5be..057bbcdb3c74 100644
>>>> --- a/drivers/net/can/m_can/Makefile
>>>> +++ b/drivers/net/can/m_can/Makefile
>>>> @@ -3,3 +3,4 @@
>>>>  #
>>>>  
>>>>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
>>>> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
>>>> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
>>>> index 9b449400376b..a60278d94126 100644
>>>> --- a/drivers/net/can/m_can/m_can.c
>>>> +++ b/drivers/net/can/m_can/m_can.c
>>>
>>> ... snip...
>>>
>>>> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>>>> +				    struct net_device *dev)
>>>> +{
>>>> +	struct m_can_priv *priv = netdev_priv(dev);
>>>> +
>>>> +	if (can_dropped_invalid_skb(dev, skb))
>>>> +		return NETDEV_TX_OK;
>>>> +
>>>> +	if (priv->is_peripherial) {
>>>> +		if (priv->tx_skb) {
>>>> +			netdev_err(dev, "hard_xmit called while tx busy\n");
>>>> +			return NETDEV_TX_BUSY;
>>>> +		}
>>>
>>> The problem with that approach is, that the upper layer will try to
>>> resubmit the current "skb" but not the previous "tx_skb". And the
>>> previous "tx_skb" has not been freed yet. I would just drop and free the
>>> skb and return NETDEV_TX_OK in m_can_tx_handler() for peripheral devices
>>> (like can_dropped_invalid_skb() does).
>>>
>>
>> OK.
>>
>> So would this also be a bug in the hi3110 and mcp251x drivers (line 521) as well because besides checking tx_length
>> this is how these drivers are written.
> 
> This is different. When entering the "start_xmit" routine, the previous
> TX is still in progress. It will (hopefully) complete soon. Therefore
> returning NETDEV_TX_BUSY is OK. The "start_xmit" routine will be
> recalled soon with the same "skb". That scenario should/could also not
> happen.

In principle, this also applies to the m_can peripheral devices. If
tx_skb is not NULL, the TX is still in progress and returning
NETDEV_TX_BUSY is just fine.

> 
> In contrast, in "m_can_tx_handler()", the skb could not be handled
> because the FIFO is full. The "start_xmit" routine for peripheral
> devices for that skb already returned NETDEV_TX_OK. Therefore the only
> meaningful action is to drop the skb. Also this error should not happen
> and if, something is going really wrong. Therefore I think, a
> WARN_ONCE() would be even more appropriate. But that should be a
> separate patch.

But that's a different issue/error. The tx_skb cannot be processed in
"m_can_tx_handler()". Either we drop it or we re-queue it (retry later).

>>
>> In addition in the peripheral context the work queue does not report up to the upper layer the status.
>> Again the hi3110 and mcp251x drivers are written this way.
>>
>> The only issue I see here is that the dropped and invalid check needs to come after the tx_skb check.
> 
> See above.

Wolfgang.

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 1/4] can: m_can: Create a m_can platform framework
  2019-03-08 14:41       ` Wolfgang Grandegger
@ 2019-03-08 15:48         ` Dan Murphy
  2019-03-08 17:08           ` Wolfgang Grandegger
  0 siblings, 1 reply; 18+ messages in thread
From: Dan Murphy @ 2019-03-08 15:48 UTC (permalink / raw)
  To: Wolfgang Grandegger, mkl, davem; +Cc: linux-can, netdev, linux-kernel

Wolfgang

On 3/8/19 8:41 AM, Wolfgang Grandegger wrote:
> Hello Dan,
> 
> thinking more about it...
> 
> Am 08.03.19 um 14:29 schrieb Wolfgang Grandegger:
>> Hello Dan,
>>
>> Am 08.03.19 um 13:44 schrieb Dan Murphy:
>>> Wolfgang
>>>
>>> On 3/8/19 4:10 AM, Wolfgang Grandegger wrote:
>>>> Hallo Dan,
>>>>
>>>> Am 05.03.19 um 16:52 schrieb Dan Murphy:
>>>>> Create a m_can platform framework that peripherial
>>>>> devices can register to and use common code and register sets.
>>>>> The peripherial devices may provide read/write and configuration
>>>>> support of the IP.
>>>>>
>>>>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>>>>> ---
>>>>>
>>>>>
>>>>> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
>>>>> start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/
>>>>>
>>>>> v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
>>>>> issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
>>>>> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
>>>>> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
>>>>> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/
>>>>>
>>>>>  drivers/net/can/m_can/Kconfig          |  13 +-
>>>>>  drivers/net/can/m_can/Makefile         |   1 +
>>>>>  drivers/net/can/m_can/m_can.c          | 700 +++++++++++++------------
>>>>>  drivers/net/can/m_can/m_can.h          | 110 ++++
>>>>>  drivers/net/can/m_can/m_can_platform.c | 202 +++++++
>>>>>  5 files changed, 682 insertions(+), 344 deletions(-)
>>>>>  create mode 100644 drivers/net/can/m_can/m_can.h
>>>>>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
>>>>>
>>>>> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
>>>>> index 04f20dd39007..f7119fd72df4 100644
>>>>> --- a/drivers/net/can/m_can/Kconfig
>>>>> +++ b/drivers/net/can/m_can/Kconfig
>>>>> @@ -1,5 +1,14 @@
>>>>>  config CAN_M_CAN
>>>>> +	tristate "Bosch M_CAN support"
>>>>> +	---help---
>>>>> +	  Say Y here if you want support for Bosch M_CAN controller framework.
>>>>> +	  This is common support for devices that embed the Bosch M_CAN IP.
>>>>> +
>>>>> +config CAN_M_CAN_PLATFORM
>>>>> +	tristate "Bosch M_CAN support for io-mapped devices"
>>>>>  	depends on HAS_IOMEM
>>>>> -	tristate "Bosch M_CAN devices"
>>>>> +	depends on CAN_M_CAN
>>>>>  	---help---
>>>>> -	  Say Y here if you want to support for Bosch M_CAN controller.
>>>>> +	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>>>>> +	  This support is for devices that have the Bosch M_CAN controller
>>>>> +	  IP embedded into the device and the IP is IO Mapped to the processor.
>>>>> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
>>>>> index 8bbd7f24f5be..057bbcdb3c74 100644
>>>>> --- a/drivers/net/can/m_can/Makefile
>>>>> +++ b/drivers/net/can/m_can/Makefile
>>>>> @@ -3,3 +3,4 @@
>>>>>  #
>>>>>  
>>>>>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
>>>>> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
>>>>> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
>>>>> index 9b449400376b..a60278d94126 100644
>>>>> --- a/drivers/net/can/m_can/m_can.c
>>>>> +++ b/drivers/net/can/m_can/m_can.c
>>>>
>>>> ... snip...
>>>>
>>>>> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>>>>> +				    struct net_device *dev)
>>>>> +{
>>>>> +	struct m_can_priv *priv = netdev_priv(dev);
>>>>> +
>>>>> +	if (can_dropped_invalid_skb(dev, skb))
>>>>> +		return NETDEV_TX_OK;
>>>>> +
>>>>> +	if (priv->is_peripherial) {
>>>>> +		if (priv->tx_skb) {
>>>>> +			netdev_err(dev, "hard_xmit called while tx busy\n");
>>>>> +			return NETDEV_TX_BUSY;
>>>>> +		}
>>>>
>>>> The problem with that approach is, that the upper layer will try to
>>>> resubmit the current "skb" but not the previous "tx_skb". And the
>>>> previous "tx_skb" has not been freed yet. I would just drop and free the
>>>> skb and return NETDEV_TX_OK in m_can_tx_handler() for peripheral devices
>>>> (like can_dropped_invalid_skb() does).
>>>>
>>>
>>> OK.
>>>
>>> So would this also be a bug in the hi3110 and mcp251x drivers (line 521) as well because besides checking tx_length
>>> this is how these drivers are written.
>>
>> This is different. When entering the "start_xmit" routine, the previous
>> TX is still in progress. It will (hopefully) complete soon. Therefore
>> returning NETDEV_TX_BUSY is OK. The "start_xmit" routine will be
>> recalled soon with the same "skb". That scenario should/could also not
>> happen.
> 
> In principle, this also applies to the m_can peripheral devices. If
> tx_skb is not NULL, the TX is still in progress and returning
> NETDEV_TX_BUSY is just fine.
> 
>>
>> In contrast, in "m_can_tx_handler()", the skb could not be handled
>> because the FIFO is full. The "start_xmit" routine for peripheral
>> devices for that skb already returned NETDEV_TX_OK. Therefore the only
>> meaningful action is to drop the skb. Also this error should not happen
>> and if, something is going really wrong. Therefore I think, a
>> WARN_ONCE() would be even more appropriate. But that should be a
>> separate patch.
> 
> But that's a different issue/error. The tx_skb cannot be processed in
> "m_can_tx_handler()". Either we drop it or we re-queue it (retry later).
> 

OK I am a bit confused on this.  Are you saying this is not an issue?
Or are you saying I need to check for tx_len like the other code?

Again if this code is an issue here I believe this is an issue in the hi3110 and mcp251x

Dan


>>>
>>> In addition in the peripheral context the work queue does not report up to the upper layer the status.
>>> Again the hi3110 and mcp251x drivers are written this way.
>>>
>>> The only issue I see here is that the dropped and invalid check needs to come after the tx_skb check.
>>
>> See above.
> 
> Wolfgang.
> 


-- 
------------------
Dan Murphy

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 1/4] can: m_can: Create a m_can platform framework
  2019-03-08 15:48         ` Dan Murphy
@ 2019-03-08 17:08           ` Wolfgang Grandegger
  2019-03-08 17:25             ` Dan Murphy
  0 siblings, 1 reply; 18+ messages in thread
From: Wolfgang Grandegger @ 2019-03-08 17:08 UTC (permalink / raw)
  To: Dan Murphy, mkl, davem; +Cc: linux-can, netdev, linux-kernel

Hello,

Am 08.03.19 um 16:48 schrieb Dan Murphy:
> Wolfgang
> 
> On 3/8/19 8:41 AM, Wolfgang Grandegger wrote:
>> Hello Dan,
>>
>> thinking more about it...
>>
>> Am 08.03.19 um 14:29 schrieb Wolfgang Grandegger:
>>> Hello Dan,
>>>
>>> Am 08.03.19 um 13:44 schrieb Dan Murphy:
>>>> Wolfgang
>>>>
>>>> On 3/8/19 4:10 AM, Wolfgang Grandegger wrote:
>>>>> Hallo Dan,
>>>>>
>>>>> Am 05.03.19 um 16:52 schrieb Dan Murphy:
>>>>>> Create a m_can platform framework that peripherial
>>>>>> devices can register to and use common code and register sets.
>>>>>> The peripherial devices may provide read/write and configuration
>>>>>> support of the IP.
>>>>>>
>>>>>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>>>>>> ---
>>>>>>
>>>>>>
>>>>>> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
>>>>>> start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/
>>>>>>
>>>>>> v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
>>>>>> issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
>>>>>> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
>>>>>> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
>>>>>> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/
>>>>>>
>>>>>>  drivers/net/can/m_can/Kconfig          |  13 +-
>>>>>>  drivers/net/can/m_can/Makefile         |   1 +
>>>>>>  drivers/net/can/m_can/m_can.c          | 700 +++++++++++++------------
>>>>>>  drivers/net/can/m_can/m_can.h          | 110 ++++
>>>>>>  drivers/net/can/m_can/m_can_platform.c | 202 +++++++
>>>>>>  5 files changed, 682 insertions(+), 344 deletions(-)
>>>>>>  create mode 100644 drivers/net/can/m_can/m_can.h
>>>>>>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
>>>>>>
>>>>>> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
>>>>>> index 04f20dd39007..f7119fd72df4 100644
>>>>>> --- a/drivers/net/can/m_can/Kconfig
>>>>>> +++ b/drivers/net/can/m_can/Kconfig
>>>>>> @@ -1,5 +1,14 @@
>>>>>>  config CAN_M_CAN
>>>>>> +	tristate "Bosch M_CAN support"
>>>>>> +	---help---
>>>>>> +	  Say Y here if you want support for Bosch M_CAN controller framework.
>>>>>> +	  This is common support for devices that embed the Bosch M_CAN IP.
>>>>>> +
>>>>>> +config CAN_M_CAN_PLATFORM
>>>>>> +	tristate "Bosch M_CAN support for io-mapped devices"
>>>>>>  	depends on HAS_IOMEM
>>>>>> -	tristate "Bosch M_CAN devices"
>>>>>> +	depends on CAN_M_CAN
>>>>>>  	---help---
>>>>>> -	  Say Y here if you want to support for Bosch M_CAN controller.
>>>>>> +	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>>>>>> +	  This support is for devices that have the Bosch M_CAN controller
>>>>>> +	  IP embedded into the device and the IP is IO Mapped to the processor.
>>>>>> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
>>>>>> index 8bbd7f24f5be..057bbcdb3c74 100644
>>>>>> --- a/drivers/net/can/m_can/Makefile
>>>>>> +++ b/drivers/net/can/m_can/Makefile
>>>>>> @@ -3,3 +3,4 @@
>>>>>>  #
>>>>>>  
>>>>>>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
>>>>>> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
>>>>>> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
>>>>>> index 9b449400376b..a60278d94126 100644
>>>>>> --- a/drivers/net/can/m_can/m_can.c
>>>>>> +++ b/drivers/net/can/m_can/m_can.c
>>>>>
>>>>> ... snip...
>>>>>
>>>>>> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>>>>>> +				    struct net_device *dev)
>>>>>> +{
>>>>>> +	struct m_can_priv *priv = netdev_priv(dev);
>>>>>> +
>>>>>> +	if (can_dropped_invalid_skb(dev, skb))
>>>>>> +		return NETDEV_TX_OK;
>>>>>> +
>>>>>> +	if (priv->is_peripherial) {
>>>>>> +		if (priv->tx_skb) {
>>>>>> +			netdev_err(dev, "hard_xmit called while tx busy\n");
>>>>>> +			return NETDEV_TX_BUSY;
>>>>>> +		}
>>>>>
>>>>> The problem with that approach is, that the upper layer will try to
>>>>> resubmit the current "skb" but not the previous "tx_skb". And the
>>>>> previous "tx_skb" has not been freed yet. I would just drop and free the
>>>>> skb and return NETDEV_TX_OK in m_can_tx_handler() for peripheral devices
>>>>> (like can_dropped_invalid_skb() does).
>>>>>
>>>>
>>>> OK.
>>>>
>>>> So would this also be a bug in the hi3110 and mcp251x drivers (line 521) as well because besides checking tx_length
>>>> this is how these drivers are written.
>>>
>>> This is different. When entering the "start_xmit" routine, the previous
>>> TX is still in progress. It will (hopefully) complete soon. Therefore
>>> returning NETDEV_TX_BUSY is OK. The "start_xmit" routine will be
>>> recalled soon with the same "skb". That scenario should/could also not
>>> happen.
>>
>> In principle, this also applies to the m_can peripheral devices. If
>> tx_skb is not NULL, the TX is still in progress and returning
>> NETDEV_TX_BUSY is just fine.
>>
>>>
>>> In contrast, in "m_can_tx_handler()", the skb could not be handled
>>> because the FIFO is full. The "start_xmit" routine for peripheral
>>> devices for that skb already returned NETDEV_TX_OK. Therefore the only
>>> meaningful action is to drop the skb. Also this error should not happen
>>> and if, something is going really wrong. Therefore I think, a
>>> WARN_ONCE() would be even more appropriate. But that should be a
>>> separate patch.
>>
>> But that's a different issue/error. The tx_skb cannot be processed in
>> "m_can_tx_handler()". Either we drop it or we re-queue it (retry later).
>>
> 
> OK I am a bit confused on this.  Are you saying this is not an issue?
> Or are you saying I need to check for tx_len like the other code?

If you check for tx_skb in the "start_xmit" routine like the hi3110 and
mcp251x, it will work the same way. But only, if the "tx_handler()" has
fully processed the message. It simple means, the TX is still in
progress and will complete soon. But in "m_can_tx_handler()" we return
without handling the message! It will never be sent and freed. Or will
the "m_can_tx_handler()" retry?

> Again if this code is an issue here I believe this is an issue in the hi3110 and mcp251x

I don't think so.

Sorry for confusion.

Wolfgang.


^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 1/4] can: m_can: Create a m_can platform framework
  2019-03-08 17:08           ` Wolfgang Grandegger
@ 2019-03-08 17:25             ` Dan Murphy
  2019-03-08 17:40               ` Wolfgang Grandegger
  0 siblings, 1 reply; 18+ messages in thread
From: Dan Murphy @ 2019-03-08 17:25 UTC (permalink / raw)
  To: Wolfgang Grandegger, mkl, davem; +Cc: linux-can, netdev, linux-kernel

On 3/8/19 11:08 AM, Wolfgang Grandegger wrote:
> Hello,
> 
> Am 08.03.19 um 16:48 schrieb Dan Murphy:
>> Wolfgang
>>
>> On 3/8/19 8:41 AM, Wolfgang Grandegger wrote:
>>> Hello Dan,
>>>
>>> thinking more about it...
>>>
>>> Am 08.03.19 um 14:29 schrieb Wolfgang Grandegger:
>>>> Hello Dan,
>>>>
>>>> Am 08.03.19 um 13:44 schrieb Dan Murphy:
>>>>> Wolfgang
>>>>>
>>>>> On 3/8/19 4:10 AM, Wolfgang Grandegger wrote:
>>>>>> Hallo Dan,
>>>>>>
>>>>>> Am 05.03.19 um 16:52 schrieb Dan Murphy:
>>>>>>> Create a m_can platform framework that peripherial
>>>>>>> devices can register to and use common code and register sets.
>>>>>>> The peripherial devices may provide read/write and configuration
>>>>>>> support of the IP.
>>>>>>>
>>>>>>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>>>>>>> ---
>>>>>>>
>>>>>>>
>>>>>>> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
>>>>>>> start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/
>>>>>>>
>>>>>>> v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
>>>>>>> issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
>>>>>>> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
>>>>>>> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
>>>>>>> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/
>>>>>>>
>>>>>>>  drivers/net/can/m_can/Kconfig          |  13 +-
>>>>>>>  drivers/net/can/m_can/Makefile         |   1 +
>>>>>>>  drivers/net/can/m_can/m_can.c          | 700 +++++++++++++------------
>>>>>>>  drivers/net/can/m_can/m_can.h          | 110 ++++
>>>>>>>  drivers/net/can/m_can/m_can_platform.c | 202 +++++++
>>>>>>>  5 files changed, 682 insertions(+), 344 deletions(-)
>>>>>>>  create mode 100644 drivers/net/can/m_can/m_can.h
>>>>>>>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
>>>>>>>
>>>>>>> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
>>>>>>> index 04f20dd39007..f7119fd72df4 100644
>>>>>>> --- a/drivers/net/can/m_can/Kconfig
>>>>>>> +++ b/drivers/net/can/m_can/Kconfig
>>>>>>> @@ -1,5 +1,14 @@
>>>>>>>  config CAN_M_CAN
>>>>>>> +	tristate "Bosch M_CAN support"
>>>>>>> +	---help---
>>>>>>> +	  Say Y here if you want support for Bosch M_CAN controller framework.
>>>>>>> +	  This is common support for devices that embed the Bosch M_CAN IP.
>>>>>>> +
>>>>>>> +config CAN_M_CAN_PLATFORM
>>>>>>> +	tristate "Bosch M_CAN support for io-mapped devices"
>>>>>>>  	depends on HAS_IOMEM
>>>>>>> -	tristate "Bosch M_CAN devices"
>>>>>>> +	depends on CAN_M_CAN
>>>>>>>  	---help---
>>>>>>> -	  Say Y here if you want to support for Bosch M_CAN controller.
>>>>>>> +	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>>>>>>> +	  This support is for devices that have the Bosch M_CAN controller
>>>>>>> +	  IP embedded into the device and the IP is IO Mapped to the processor.
>>>>>>> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
>>>>>>> index 8bbd7f24f5be..057bbcdb3c74 100644
>>>>>>> --- a/drivers/net/can/m_can/Makefile
>>>>>>> +++ b/drivers/net/can/m_can/Makefile
>>>>>>> @@ -3,3 +3,4 @@
>>>>>>>  #
>>>>>>>  
>>>>>>>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
>>>>>>> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
>>>>>>> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
>>>>>>> index 9b449400376b..a60278d94126 100644
>>>>>>> --- a/drivers/net/can/m_can/m_can.c
>>>>>>> +++ b/drivers/net/can/m_can/m_can.c
>>>>>>
>>>>>> ... snip...
>>>>>>
>>>>>>> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>>>>>>> +				    struct net_device *dev)
>>>>>>> +{
>>>>>>> +	struct m_can_priv *priv = netdev_priv(dev);
>>>>>>> +
>>>>>>> +	if (can_dropped_invalid_skb(dev, skb))
>>>>>>> +		return NETDEV_TX_OK;
>>>>>>> +
>>>>>>> +	if (priv->is_peripherial) {
>>>>>>> +		if (priv->tx_skb) {
>>>>>>> +			netdev_err(dev, "hard_xmit called while tx busy\n");
>>>>>>> +			return NETDEV_TX_BUSY;
>>>>>>> +		}
>>>>>>
>>>>>> The problem with that approach is, that the upper layer will try to
>>>>>> resubmit the current "skb" but not the previous "tx_skb". And the
>>>>>> previous "tx_skb" has not been freed yet. I would just drop and free the
>>>>>> skb and return NETDEV_TX_OK in m_can_tx_handler() for peripheral devices
>>>>>> (like can_dropped_invalid_skb() does).
>>>>>>
>>>>>
>>>>> OK.
>>>>>
>>>>> So would this also be a bug in the hi3110 and mcp251x drivers (line 521) as well because besides checking tx_length
>>>>> this is how these drivers are written.
>>>>
>>>> This is different. When entering the "start_xmit" routine, the previous
>>>> TX is still in progress. It will (hopefully) complete soon. Therefore
>>>> returning NETDEV_TX_BUSY is OK. The "start_xmit" routine will be
>>>> recalled soon with the same "skb". That scenario should/could also not
>>>> happen.
>>>
>>> In principle, this also applies to the m_can peripheral devices. If
>>> tx_skb is not NULL, the TX is still in progress and returning
>>> NETDEV_TX_BUSY is just fine.
>>>
>>>>
>>>> In contrast, in "m_can_tx_handler()", the skb could not be handled
>>>> because the FIFO is full. The "start_xmit" routine for peripheral
>>>> devices for that skb already returned NETDEV_TX_OK. Therefore the only
>>>> meaningful action is to drop the skb. Also this error should not happen
>>>> and if, something is going really wrong. Therefore I think, a
>>>> WARN_ONCE() would be even more appropriate. But that should be a
>>>> separate patch.
>>>
>>> But that's a different issue/error. The tx_skb cannot be processed in
>>> "m_can_tx_handler()". Either we drop it or we re-queue it (retry later).
>>>
>>
>> OK I am a bit confused on this.  Are you saying this is not an issue?
>> Or are you saying I need to check for tx_len like the other code?
> 
> If you check for tx_skb in the "start_xmit" routine like the hi3110 and
> mcp251x, it will work the same way. But only, if the "tx_handler()" has
> fully processed the message. It simple means, the TX is still in
> progress and will complete soon. But in "m_can_tx_handler()" we return
> without handling the message! It will never be sent and freed. Or will
> the "m_can_tx_handler()" retry?
> 

I am not seeing where we are not handling the message in the m_can_tx_handler()

In the peripheral code the work is queued up.  And the work thread is m_can_tx_work_queue.

This in turn calls the m_can_tx_handler and the worker is blocked until return which means the message
would have been processed.

If there is no issue and the handler returns OK then the skb is set to null.
Otherwise the only other time that the skb will not be null is if the FIFO was full.

Plus there can only be one work queue at a time so the processing is synchronous.
If the upper layer decides to send another packet before the prior one is complete then it will get
a TX busy return.

IOmapped calls are blocked on return so this is not an issue.  We cannot do it the same way with peripherals due to the
atomic context of the request.

Dan

>> Again if this code is an issue here I believe this is an issue in the hi3110 and mcp251x
> 
> I don't think so.
> 
> Sorry for confusion.
> 
> Wolfgang.
> 


-- 
------------------
Dan Murphy

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 1/4] can: m_can: Create a m_can platform framework
  2019-03-08 17:25             ` Dan Murphy
@ 2019-03-08 17:40               ` Wolfgang Grandegger
  2019-03-08 17:52                 ` Dan Murphy
  0 siblings, 1 reply; 18+ messages in thread
From: Wolfgang Grandegger @ 2019-03-08 17:40 UTC (permalink / raw)
  To: Dan Murphy, mkl, davem; +Cc: linux-can, netdev, linux-kernel

Hello Dan,

Am 08.03.19 um 18:25 schrieb Dan Murphy:
> On 3/8/19 11:08 AM, Wolfgang Grandegger wrote:
>> Hello,
>>
>> Am 08.03.19 um 16:48 schrieb Dan Murphy:
>>> Wolfgang
>>>
>>> On 3/8/19 8:41 AM, Wolfgang Grandegger wrote:
>>>> Hello Dan,
>>>>
>>>> thinking more about it...
>>>>
>>>> Am 08.03.19 um 14:29 schrieb Wolfgang Grandegger:
>>>>> Hello Dan,
>>>>>
>>>>> Am 08.03.19 um 13:44 schrieb Dan Murphy:
>>>>>> Wolfgang
>>>>>>
>>>>>> On 3/8/19 4:10 AM, Wolfgang Grandegger wrote:
>>>>>>> Hallo Dan,
>>>>>>>
>>>>>>> Am 05.03.19 um 16:52 schrieb Dan Murphy:
>>>>>>>> Create a m_can platform framework that peripherial
>>>>>>>> devices can register to and use common code and register sets.
>>>>>>>> The peripherial devices may provide read/write and configuration
>>>>>>>> support of the IP.
>>>>>>>>
>>>>>>>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>>>>>>>> ---
>>>>>>>>
>>>>>>>>
>>>>>>>> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
>>>>>>>> start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/
>>>>>>>>
>>>>>>>> v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
>>>>>>>> issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
>>>>>>>> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
>>>>>>>> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
>>>>>>>> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/
>>>>>>>>
>>>>>>>>  drivers/net/can/m_can/Kconfig          |  13 +-
>>>>>>>>  drivers/net/can/m_can/Makefile         |   1 +
>>>>>>>>  drivers/net/can/m_can/m_can.c          | 700 +++++++++++++------------
>>>>>>>>  drivers/net/can/m_can/m_can.h          | 110 ++++
>>>>>>>>  drivers/net/can/m_can/m_can_platform.c | 202 +++++++
>>>>>>>>  5 files changed, 682 insertions(+), 344 deletions(-)
>>>>>>>>  create mode 100644 drivers/net/can/m_can/m_can.h
>>>>>>>>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
>>>>>>>>
>>>>>>>> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
>>>>>>>> index 04f20dd39007..f7119fd72df4 100644
>>>>>>>> --- a/drivers/net/can/m_can/Kconfig
>>>>>>>> +++ b/drivers/net/can/m_can/Kconfig
>>>>>>>> @@ -1,5 +1,14 @@
>>>>>>>>  config CAN_M_CAN
>>>>>>>> +	tristate "Bosch M_CAN support"
>>>>>>>> +	---help---
>>>>>>>> +	  Say Y here if you want support for Bosch M_CAN controller framework.
>>>>>>>> +	  This is common support for devices that embed the Bosch M_CAN IP.
>>>>>>>> +
>>>>>>>> +config CAN_M_CAN_PLATFORM
>>>>>>>> +	tristate "Bosch M_CAN support for io-mapped devices"
>>>>>>>>  	depends on HAS_IOMEM
>>>>>>>> -	tristate "Bosch M_CAN devices"
>>>>>>>> +	depends on CAN_M_CAN
>>>>>>>>  	---help---
>>>>>>>> -	  Say Y here if you want to support for Bosch M_CAN controller.
>>>>>>>> +	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>>>>>>>> +	  This support is for devices that have the Bosch M_CAN controller
>>>>>>>> +	  IP embedded into the device and the IP is IO Mapped to the processor.
>>>>>>>> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
>>>>>>>> index 8bbd7f24f5be..057bbcdb3c74 100644
>>>>>>>> --- a/drivers/net/can/m_can/Makefile
>>>>>>>> +++ b/drivers/net/can/m_can/Makefile
>>>>>>>> @@ -3,3 +3,4 @@
>>>>>>>>  #
>>>>>>>>  
>>>>>>>>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
>>>>>>>> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
>>>>>>>> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
>>>>>>>> index 9b449400376b..a60278d94126 100644
>>>>>>>> --- a/drivers/net/can/m_can/m_can.c
>>>>>>>> +++ b/drivers/net/can/m_can/m_can.c
>>>>>>>
>>>>>>> ... snip...
>>>>>>>
>>>>>>>> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>>>>>>>> +				    struct net_device *dev)
>>>>>>>> +{
>>>>>>>> +	struct m_can_priv *priv = netdev_priv(dev);
>>>>>>>> +
>>>>>>>> +	if (can_dropped_invalid_skb(dev, skb))
>>>>>>>> +		return NETDEV_TX_OK;
>>>>>>>> +
>>>>>>>> +	if (priv->is_peripherial) {
>>>>>>>> +		if (priv->tx_skb) {
>>>>>>>> +			netdev_err(dev, "hard_xmit called while tx busy\n");
>>>>>>>> +			return NETDEV_TX_BUSY;
>>>>>>>> +		}
>>>>>>>
>>>>>>> The problem with that approach is, that the upper layer will try to
>>>>>>> resubmit the current "skb" but not the previous "tx_skb". And the
>>>>>>> previous "tx_skb" has not been freed yet. I would just drop and free the
>>>>>>> skb and return NETDEV_TX_OK in m_can_tx_handler() for peripheral devices
>>>>>>> (like can_dropped_invalid_skb() does).
>>>>>>>
>>>>>>
>>>>>> OK.
>>>>>>
>>>>>> So would this also be a bug in the hi3110 and mcp251x drivers (line 521) as well because besides checking tx_length
>>>>>> this is how these drivers are written.
>>>>>
>>>>> This is different. When entering the "start_xmit" routine, the previous
>>>>> TX is still in progress. It will (hopefully) complete soon. Therefore
>>>>> returning NETDEV_TX_BUSY is OK. The "start_xmit" routine will be
>>>>> recalled soon with the same "skb". That scenario should/could also not
>>>>> happen.
>>>>
>>>> In principle, this also applies to the m_can peripheral devices. If
>>>> tx_skb is not NULL, the TX is still in progress and returning
>>>> NETDEV_TX_BUSY is just fine.
>>>>
>>>>>
>>>>> In contrast, in "m_can_tx_handler()", the skb could not be handled
>>>>> because the FIFO is full. The "start_xmit" routine for peripheral
>>>>> devices for that skb already returned NETDEV_TX_OK. Therefore the only
>>>>> meaningful action is to drop the skb. Also this error should not happen
>>>>> and if, something is going really wrong. Therefore I think, a
>>>>> WARN_ONCE() would be even more appropriate. But that should be a
>>>>> separate patch.
>>>>
>>>> But that's a different issue/error. The tx_skb cannot be processed in
>>>> "m_can_tx_handler()". Either we drop it or we re-queue it (retry later).
>>>>
>>>
>>> OK I am a bit confused on this.  Are you saying this is not an issue?
>>> Or are you saying I need to check for tx_len like the other code?
>>
>> If you check for tx_skb in the "start_xmit" routine like the hi3110 and
>> mcp251x, it will work the same way. But only, if the "tx_handler()" has
>> fully processed the message. It simple means, the TX is still in
>> progress and will complete soon. But in "m_can_tx_handler()" we return
>> without handling the message! It will never be sent and freed. Or will
>> the "m_can_tx_handler()" retry?
>>
> 
> I am not seeing where we are not handling the message in the m_can_tx_handler()

static void m_can_tx_handler(struct m_can_classdev *priv)
{
		...
		/* Check if FIFO full */
		if (m_can_tx_fifo_full(priv)) {
			/* This shouldn't happen */
			netif_stop_queue(dev);
			netdev_warn(dev,
				    "TX queue active although FIFO is full.");
			return;
		}

We simply return here. When is the message (tx_skb) processed (sent or freed)?
What happens with tx_skb?


For the hi3110, we have:

static void hi3110_tx_work_handler(struct work_struct *ws)
{
        struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
                                                tx_work);
        struct spi_device *spi = priv->spi;
        struct net_device *net = priv->net;
        struct can_frame *frame;

        mutex_lock(&priv->hi3110_lock);
        if (priv->tx_skb) {
                if (priv->can.state == CAN_STATE_BUS_OFF) {
                        hi3110_clean(net);
                } else {
                        frame = (struct can_frame *)priv->tx_skb->data;
                        hi3110_hw_tx(spi, frame);
                        priv->tx_len = 1 + frame->can_dlc;
                        can_put_echo_skb(priv->tx_skb, net, 0);
                        priv->tx_skb = NULL;
                }
        }
        mutex_unlock(&priv->hi3110_lock);
}

Either the tx_skb is sent or cleanup (dropped and freed) in case of bus-off.
Also "hi3110_clean" sets "priv->tx_skb = NULL"! The "tx_len" handles a pending 
"echo_skb".

> 
> In the peripheral code the work is queued up.  And the work thread is m_can_tx_work_queue.
> 
> This in turn calls the m_can_tx_handler and the worker is blocked until return which means the message
> would have been processed.
> 
> If there is no issue and the handler returns OK then the skb is set to null.
> Otherwise the only other time that the skb will not be null is if the FIFO was full.
> 
> Plus there can only be one work queue at a time so the processing is synchronous.
> If the upper layer decides to send another packet before the prior one is complete then it will get
> a TX busy return.
> 
> IOmapped calls are blocked on return so this is not an issue.  We cannot do it the same way with peripherals due to the
> atomic context of the request.
Wolfgang.

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 1/4] can: m_can: Create a m_can platform framework
  2019-03-08 17:40               ` Wolfgang Grandegger
@ 2019-03-08 17:52                 ` Dan Murphy
  2019-03-08 18:06                   ` Wolfgang Grandegger
  0 siblings, 1 reply; 18+ messages in thread
From: Dan Murphy @ 2019-03-08 17:52 UTC (permalink / raw)
  To: Wolfgang Grandegger, mkl, davem; +Cc: linux-can, netdev, linux-kernel

On 3/8/19 11:40 AM, Wolfgang Grandegger wrote:
> Hello Dan,
> 
> Am 08.03.19 um 18:25 schrieb Dan Murphy:
>> On 3/8/19 11:08 AM, Wolfgang Grandegger wrote:
>>> Hello,
>>>
>>> Am 08.03.19 um 16:48 schrieb Dan Murphy:
>>>> Wolfgang
>>>>
>>>> On 3/8/19 8:41 AM, Wolfgang Grandegger wrote:
>>>>> Hello Dan,
>>>>>
>>>>> thinking more about it...
>>>>>
>>>>> Am 08.03.19 um 14:29 schrieb Wolfgang Grandegger:
>>>>>> Hello Dan,
>>>>>>
>>>>>> Am 08.03.19 um 13:44 schrieb Dan Murphy:
>>>>>>> Wolfgang
>>>>>>>
>>>>>>> On 3/8/19 4:10 AM, Wolfgang Grandegger wrote:
>>>>>>>> Hallo Dan,
>>>>>>>>
>>>>>>>> Am 05.03.19 um 16:52 schrieb Dan Murphy:
>>>>>>>>> Create a m_can platform framework that peripherial
>>>>>>>>> devices can register to and use common code and register sets.
>>>>>>>>> The peripherial devices may provide read/write and configuration
>>>>>>>>> support of the IP.
>>>>>>>>>
>>>>>>>>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>>>>>>>>> ---
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
>>>>>>>>> start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/
>>>>>>>>>
>>>>>>>>> v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
>>>>>>>>> issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
>>>>>>>>> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
>>>>>>>>> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
>>>>>>>>> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/
>>>>>>>>>
>>>>>>>>>  drivers/net/can/m_can/Kconfig          |  13 +-
>>>>>>>>>  drivers/net/can/m_can/Makefile         |   1 +
>>>>>>>>>  drivers/net/can/m_can/m_can.c          | 700 +++++++++++++------------
>>>>>>>>>  drivers/net/can/m_can/m_can.h          | 110 ++++
>>>>>>>>>  drivers/net/can/m_can/m_can_platform.c | 202 +++++++
>>>>>>>>>  5 files changed, 682 insertions(+), 344 deletions(-)
>>>>>>>>>  create mode 100644 drivers/net/can/m_can/m_can.h
>>>>>>>>>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
>>>>>>>>>
>>>>>>>>> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
>>>>>>>>> index 04f20dd39007..f7119fd72df4 100644
>>>>>>>>> --- a/drivers/net/can/m_can/Kconfig
>>>>>>>>> +++ b/drivers/net/can/m_can/Kconfig
>>>>>>>>> @@ -1,5 +1,14 @@
>>>>>>>>>  config CAN_M_CAN
>>>>>>>>> +	tristate "Bosch M_CAN support"
>>>>>>>>> +	---help---
>>>>>>>>> +	  Say Y here if you want support for Bosch M_CAN controller framework.
>>>>>>>>> +	  This is common support for devices that embed the Bosch M_CAN IP.
>>>>>>>>> +
>>>>>>>>> +config CAN_M_CAN_PLATFORM
>>>>>>>>> +	tristate "Bosch M_CAN support for io-mapped devices"
>>>>>>>>>  	depends on HAS_IOMEM
>>>>>>>>> -	tristate "Bosch M_CAN devices"
>>>>>>>>> +	depends on CAN_M_CAN
>>>>>>>>>  	---help---
>>>>>>>>> -	  Say Y here if you want to support for Bosch M_CAN controller.
>>>>>>>>> +	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>>>>>>>>> +	  This support is for devices that have the Bosch M_CAN controller
>>>>>>>>> +	  IP embedded into the device and the IP is IO Mapped to the processor.
>>>>>>>>> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
>>>>>>>>> index 8bbd7f24f5be..057bbcdb3c74 100644
>>>>>>>>> --- a/drivers/net/can/m_can/Makefile
>>>>>>>>> +++ b/drivers/net/can/m_can/Makefile
>>>>>>>>> @@ -3,3 +3,4 @@
>>>>>>>>>  #
>>>>>>>>>  
>>>>>>>>>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
>>>>>>>>> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
>>>>>>>>> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
>>>>>>>>> index 9b449400376b..a60278d94126 100644
>>>>>>>>> --- a/drivers/net/can/m_can/m_can.c
>>>>>>>>> +++ b/drivers/net/can/m_can/m_can.c
>>>>>>>>
>>>>>>>> ... snip...
>>>>>>>>
>>>>>>>>> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>>>>>>>>> +				    struct net_device *dev)
>>>>>>>>> +{
>>>>>>>>> +	struct m_can_priv *priv = netdev_priv(dev);
>>>>>>>>> +
>>>>>>>>> +	if (can_dropped_invalid_skb(dev, skb))
>>>>>>>>> +		return NETDEV_TX_OK;
>>>>>>>>> +
>>>>>>>>> +	if (priv->is_peripherial) {
>>>>>>>>> +		if (priv->tx_skb) {
>>>>>>>>> +			netdev_err(dev, "hard_xmit called while tx busy\n");
>>>>>>>>> +			return NETDEV_TX_BUSY;
>>>>>>>>> +		}
>>>>>>>>
>>>>>>>> The problem with that approach is, that the upper layer will try to
>>>>>>>> resubmit the current "skb" but not the previous "tx_skb". And the
>>>>>>>> previous "tx_skb" has not been freed yet. I would just drop and free the
>>>>>>>> skb and return NETDEV_TX_OK in m_can_tx_handler() for peripheral devices
>>>>>>>> (like can_dropped_invalid_skb() does).
>>>>>>>>
>>>>>>>
>>>>>>> OK.
>>>>>>>
>>>>>>> So would this also be a bug in the hi3110 and mcp251x drivers (line 521) as well because besides checking tx_length
>>>>>>> this is how these drivers are written.
>>>>>>
>>>>>> This is different. When entering the "start_xmit" routine, the previous
>>>>>> TX is still in progress. It will (hopefully) complete soon. Therefore
>>>>>> returning NETDEV_TX_BUSY is OK. The "start_xmit" routine will be
>>>>>> recalled soon with the same "skb". That scenario should/could also not
>>>>>> happen.
>>>>>
>>>>> In principle, this also applies to the m_can peripheral devices. If
>>>>> tx_skb is not NULL, the TX is still in progress and returning
>>>>> NETDEV_TX_BUSY is just fine.
>>>>>
>>>>>>
>>>>>> In contrast, in "m_can_tx_handler()", the skb could not be handled
>>>>>> because the FIFO is full. The "start_xmit" routine for peripheral
>>>>>> devices for that skb already returned NETDEV_TX_OK. Therefore the only
>>>>>> meaningful action is to drop the skb. Also this error should not happen
>>>>>> and if, something is going really wrong. Therefore I think, a
>>>>>> WARN_ONCE() would be even more appropriate. But that should be a
>>>>>> separate patch.
>>>>>
>>>>> But that's a different issue/error. The tx_skb cannot be processed in
>>>>> "m_can_tx_handler()". Either we drop it or we re-queue it (retry later).
>>>>>
>>>>
>>>> OK I am a bit confused on this.  Are you saying this is not an issue?
>>>> Or are you saying I need to check for tx_len like the other code?
>>>
>>> If you check for tx_skb in the "start_xmit" routine like the hi3110 and
>>> mcp251x, it will work the same way. But only, if the "tx_handler()" has
>>> fully processed the message. It simple means, the TX is still in
>>> progress and will complete soon. But in "m_can_tx_handler()" we return
>>> without handling the message! It will never be sent and freed. Or will
>>> the "m_can_tx_handler()" retry?
>>>
>>
>> I am not seeing where we are not handling the message in the m_can_tx_handler()
> 
> static void m_can_tx_handler(struct m_can_classdev *priv)
> {
> 		...
> 		/* Check if FIFO full */
> 		if (m_can_tx_fifo_full(priv)) {
> 			/* This shouldn't happen */
> 			netif_stop_queue(dev);
> 			netdev_warn(dev,
> 				    "TX queue active although FIFO is full.");
> 			return;
> 		}
> 
> We simply return here. When is the message (tx_skb) processed (sent or freed)?
> What happens with tx_skb?
> 

Are you sure you are looking at the right code?

For patch version v7 I have the following

		/* Check if FIFO full */
		if (m_can_tx_fifo_full(cdev)) {
			/* This shouldn't happen */
			netif_stop_queue(dev);
			netdev_warn(dev,
				    "TX queue active although FIFO is full.");
			return NETDEV_TX_BUSY;
		}

Which is no change from the original source code.

> 
> For the hi3110, we have:
> 
> static void hi3110_tx_work_handler(struct work_struct *ws)
> {
>         struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
>                                                 tx_work);
>         struct spi_device *spi = priv->spi;
>         struct net_device *net = priv->net;
>         struct can_frame *frame;
> 
>         mutex_lock(&priv->hi3110_lock);
>         if (priv->tx_skb) {
>                 if (priv->can.state == CAN_STATE_BUS_OFF) {
>                         hi3110_clean(net);
>                 } else {
>                         frame = (struct can_frame *)priv->tx_skb->data;
>                         hi3110_hw_tx(spi, frame);
>                         priv->tx_len = 1 + frame->can_dlc;
>                         can_put_echo_skb(priv->tx_skb, net, 0);
>                         priv->tx_skb = NULL;
>                 }
>         }
>         mutex_unlock(&priv->hi3110_lock);
> }
> 
> Either the tx_skb is sent or cleanup (dropped and freed) in case of bus-off.
> Also "hi3110_clean" sets "priv->tx_skb = NULL"! The "tx_len" handles a pending 
> "echo_skb".
> 
>>
>> In the peripheral code the work is queued up.  And the work thread is m_can_tx_work_queue.
>>
>> This in turn calls the m_can_tx_handler and the worker is blocked until return which means the message
>> would have been processed.
>>
>> If there is no issue and the handler returns OK then the skb is set to null.
>> Otherwise the only other time that the skb will not be null is if the FIFO was full.
>>
>> Plus there can only be one work queue at a time so the processing is synchronous.
>> If the upper layer decides to send another packet before the prior one is complete then it will get
>> a TX busy return.
>>
>> IOmapped calls are blocked on return so this is not an issue.  We cannot do it the same way with peripherals due to the
>> atomic context of the request.
> Wolfgang.
> 


-- 
------------------
Dan Murphy

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 1/4] can: m_can: Create a m_can platform framework
  2019-03-08 17:52                 ` Dan Murphy
@ 2019-03-08 18:06                   ` Wolfgang Grandegger
  2019-03-08 20:36                     ` Dan Murphy
  0 siblings, 1 reply; 18+ messages in thread
From: Wolfgang Grandegger @ 2019-03-08 18:06 UTC (permalink / raw)
  To: Dan Murphy, mkl, davem; +Cc: linux-can, netdev, linux-kernel



Am 08.03.19 um 18:52 schrieb Dan Murphy:
> On 3/8/19 11:40 AM, Wolfgang Grandegger wrote:
>> Hello Dan,
>>
>> Am 08.03.19 um 18:25 schrieb Dan Murphy:
>>> On 3/8/19 11:08 AM, Wolfgang Grandegger wrote:
>>>> Hello,
>>>>
>>>> Am 08.03.19 um 16:48 schrieb Dan Murphy:
>>>>> Wolfgang
>>>>>
>>>>> On 3/8/19 8:41 AM, Wolfgang Grandegger wrote:
>>>>>> Hello Dan,
>>>>>>
>>>>>> thinking more about it...
>>>>>>
>>>>>> Am 08.03.19 um 14:29 schrieb Wolfgang Grandegger:
>>>>>>> Hello Dan,
>>>>>>>
>>>>>>> Am 08.03.19 um 13:44 schrieb Dan Murphy:
>>>>>>>> Wolfgang
>>>>>>>>
>>>>>>>> On 3/8/19 4:10 AM, Wolfgang Grandegger wrote:
>>>>>>>>> Hallo Dan,
>>>>>>>>>
>>>>>>>>> Am 05.03.19 um 16:52 schrieb Dan Murphy:
>>>>>>>>>> Create a m_can platform framework that peripherial
>>>>>>>>>> devices can register to and use common code and register sets.
>>>>>>>>>> The peripherial devices may provide read/write and configuration
>>>>>>>>>> support of the IP.
>>>>>>>>>>
>>>>>>>>>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>>>>>>>>>> ---
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
>>>>>>>>>> start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/
>>>>>>>>>>
>>>>>>>>>> v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
>>>>>>>>>> issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
>>>>>>>>>> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
>>>>>>>>>> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
>>>>>>>>>> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/
>>>>>>>>>>
>>>>>>>>>>  drivers/net/can/m_can/Kconfig          |  13 +-
>>>>>>>>>>  drivers/net/can/m_can/Makefile         |   1 +
>>>>>>>>>>  drivers/net/can/m_can/m_can.c          | 700 +++++++++++++------------
>>>>>>>>>>  drivers/net/can/m_can/m_can.h          | 110 ++++
>>>>>>>>>>  drivers/net/can/m_can/m_can_platform.c | 202 +++++++
>>>>>>>>>>  5 files changed, 682 insertions(+), 344 deletions(-)
>>>>>>>>>>  create mode 100644 drivers/net/can/m_can/m_can.h
>>>>>>>>>>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
>>>>>>>>>>
>>>>>>>>>> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
>>>>>>>>>> index 04f20dd39007..f7119fd72df4 100644
>>>>>>>>>> --- a/drivers/net/can/m_can/Kconfig
>>>>>>>>>> +++ b/drivers/net/can/m_can/Kconfig
>>>>>>>>>> @@ -1,5 +1,14 @@
>>>>>>>>>>  config CAN_M_CAN
>>>>>>>>>> +	tristate "Bosch M_CAN support"
>>>>>>>>>> +	---help---
>>>>>>>>>> +	  Say Y here if you want support for Bosch M_CAN controller framework.
>>>>>>>>>> +	  This is common support for devices that embed the Bosch M_CAN IP.
>>>>>>>>>> +
>>>>>>>>>> +config CAN_M_CAN_PLATFORM
>>>>>>>>>> +	tristate "Bosch M_CAN support for io-mapped devices"
>>>>>>>>>>  	depends on HAS_IOMEM
>>>>>>>>>> -	tristate "Bosch M_CAN devices"
>>>>>>>>>> +	depends on CAN_M_CAN
>>>>>>>>>>  	---help---
>>>>>>>>>> -	  Say Y here if you want to support for Bosch M_CAN controller.
>>>>>>>>>> +	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>>>>>>>>>> +	  This support is for devices that have the Bosch M_CAN controller
>>>>>>>>>> +	  IP embedded into the device and the IP is IO Mapped to the processor.
>>>>>>>>>> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
>>>>>>>>>> index 8bbd7f24f5be..057bbcdb3c74 100644
>>>>>>>>>> --- a/drivers/net/can/m_can/Makefile
>>>>>>>>>> +++ b/drivers/net/can/m_can/Makefile
>>>>>>>>>> @@ -3,3 +3,4 @@
>>>>>>>>>>  #
>>>>>>>>>>  
>>>>>>>>>>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
>>>>>>>>>> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
>>>>>>>>>> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
>>>>>>>>>> index 9b449400376b..a60278d94126 100644
>>>>>>>>>> --- a/drivers/net/can/m_can/m_can.c
>>>>>>>>>> +++ b/drivers/net/can/m_can/m_can.c
>>>>>>>>>
>>>>>>>>> ... snip...
>>>>>>>>>
>>>>>>>>>> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>>>>>>>>>> +				    struct net_device *dev)
>>>>>>>>>> +{
>>>>>>>>>> +	struct m_can_priv *priv = netdev_priv(dev);
>>>>>>>>>> +
>>>>>>>>>> +	if (can_dropped_invalid_skb(dev, skb))
>>>>>>>>>> +		return NETDEV_TX_OK;
>>>>>>>>>> +
>>>>>>>>>> +	if (priv->is_peripherial) {
>>>>>>>>>> +		if (priv->tx_skb) {
>>>>>>>>>> +			netdev_err(dev, "hard_xmit called while tx busy\n");
>>>>>>>>>> +			return NETDEV_TX_BUSY;
>>>>>>>>>> +		}
>>>>>>>>>
>>>>>>>>> The problem with that approach is, that the upper layer will try to
>>>>>>>>> resubmit the current "skb" but not the previous "tx_skb". And the
>>>>>>>>> previous "tx_skb" has not been freed yet. I would just drop and free the
>>>>>>>>> skb and return NETDEV_TX_OK in m_can_tx_handler() for peripheral devices
>>>>>>>>> (like can_dropped_invalid_skb() does).
>>>>>>>>>
>>>>>>>>
>>>>>>>> OK.
>>>>>>>>
>>>>>>>> So would this also be a bug in the hi3110 and mcp251x drivers (line 521) as well because besides checking tx_length
>>>>>>>> this is how these drivers are written.
>>>>>>>
>>>>>>> This is different. When entering the "start_xmit" routine, the previous
>>>>>>> TX is still in progress. It will (hopefully) complete soon. Therefore
>>>>>>> returning NETDEV_TX_BUSY is OK. The "start_xmit" routine will be
>>>>>>> recalled soon with the same "skb". That scenario should/could also not
>>>>>>> happen.
>>>>>>
>>>>>> In principle, this also applies to the m_can peripheral devices. If
>>>>>> tx_skb is not NULL, the TX is still in progress and returning
>>>>>> NETDEV_TX_BUSY is just fine.
>>>>>>
>>>>>>>
>>>>>>> In contrast, in "m_can_tx_handler()", the skb could not be handled
>>>>>>> because the FIFO is full. The "start_xmit" routine for peripheral
>>>>>>> devices for that skb already returned NETDEV_TX_OK. Therefore the only
>>>>>>> meaningful action is to drop the skb. Also this error should not happen
>>>>>>> and if, something is going really wrong. Therefore I think, a
>>>>>>> WARN_ONCE() would be even more appropriate. But that should be a
>>>>>>> separate patch.
>>>>>>
>>>>>> But that's a different issue/error. The tx_skb cannot be processed in
>>>>>> "m_can_tx_handler()". Either we drop it or we re-queue it (retry later).
>>>>>>
>>>>>
>>>>> OK I am a bit confused on this.  Are you saying this is not an issue?
>>>>> Or are you saying I need to check for tx_len like the other code?
>>>>
>>>> If you check for tx_skb in the "start_xmit" routine like the hi3110 and
>>>> mcp251x, it will work the same way. But only, if the "tx_handler()" has
>>>> fully processed the message. It simple means, the TX is still in
>>>> progress and will complete soon. But in "m_can_tx_handler()" we return
>>>> without handling the message! It will never be sent and freed. Or will
>>>> the "m_can_tx_handler()" retry?
>>>>
>>>
>>> I am not seeing where we are not handling the message in the m_can_tx_handler()
>>
>> static void m_can_tx_handler(struct m_can_classdev *priv)
>> {
>> 		...
>> 		/* Check if FIFO full */
>> 		if (m_can_tx_fifo_full(priv)) {
>> 			/* This shouldn't happen */
>> 			netif_stop_queue(dev);
>> 			netdev_warn(dev,
>> 				    "TX queue active although FIFO is full.");
>> 			return;
>> 		}
>>
>> We simply return here. When is the message (tx_skb) processed (sent or freed)?
>> What happens with tx_skb?
>>
> 
> Are you sure you are looking at the right code?
> 
> For patch version v7 I have the following
> 
> 		/* Check if FIFO full */
> 		if (m_can_tx_fifo_full(cdev)) {
> 			/* This shouldn't happen */
> 			netif_stop_queue(dev);
> 			netdev_warn(dev,
> 				    "TX queue active although FIFO is full.");
> 			return NETDEV_TX_BUSY;
> 		}
> 
> Which is no change from the original source code.

I know,  but for the peripheral devices you have:

  static void m_can_tx_work_queue(struct work_struct *ws)
  {
	struct m_can_priv *priv = container_of(ws, struct m_can_priv,
						tx_work);
	netdev_tx_t ret;

	ret = m_can_tx_handler(priv);
	if (ret == NETDEV_TX_OK)
		priv->tx_skb = NULL;
  }

What will happen with tx_skb if NETDEV_TX_BUSY? It has not been
dropped/freed yet?

Wolfgang.

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 1/4] can: m_can: Create a m_can platform framework
  2019-03-08 18:06                   ` Wolfgang Grandegger
@ 2019-03-08 20:36                     ` Dan Murphy
  2019-03-11 11:19                       ` Wolfgang Grandegger
  0 siblings, 1 reply; 18+ messages in thread
From: Dan Murphy @ 2019-03-08 20:36 UTC (permalink / raw)
  To: Wolfgang Grandegger, mkl, davem; +Cc: linux-can, netdev, linux-kernel

On 3/8/19 12:06 PM, Wolfgang Grandegger wrote:
> 
> 
> Am 08.03.19 um 18:52 schrieb Dan Murphy:
>> On 3/8/19 11:40 AM, Wolfgang Grandegger wrote:
>>> Hello Dan,
>>>
>>> Am 08.03.19 um 18:25 schrieb Dan Murphy:
>>>> On 3/8/19 11:08 AM, Wolfgang Grandegger wrote:
>>>>> Hello,
>>>>>
>>>>> Am 08.03.19 um 16:48 schrieb Dan Murphy:
>>>>>> Wolfgang
>>>>>>
>>>>>> On 3/8/19 8:41 AM, Wolfgang Grandegger wrote:
>>>>>>> Hello Dan,
>>>>>>>
>>>>>>> thinking more about it...
>>>>>>>
>>>>>>> Am 08.03.19 um 14:29 schrieb Wolfgang Grandegger:
>>>>>>>> Hello Dan,
>>>>>>>>
>>>>>>>> Am 08.03.19 um 13:44 schrieb Dan Murphy:
>>>>>>>>> Wolfgang
>>>>>>>>>
>>>>>>>>> On 3/8/19 4:10 AM, Wolfgang Grandegger wrote:
>>>>>>>>>> Hallo Dan,
>>>>>>>>>>
>>>>>>>>>> Am 05.03.19 um 16:52 schrieb Dan Murphy:
>>>>>>>>>>> Create a m_can platform framework that peripherial
>>>>>>>>>>> devices can register to and use common code and register sets.
>>>>>>>>>>> The peripherial devices may provide read/write and configuration
>>>>>>>>>>> support of the IP.
>>>>>>>>>>>
>>>>>>>>>>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>>>>>>>>>>> ---
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
>>>>>>>>>>> start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/
>>>>>>>>>>>
>>>>>>>>>>> v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
>>>>>>>>>>> issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
>>>>>>>>>>> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
>>>>>>>>>>> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
>>>>>>>>>>> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/
>>>>>>>>>>>
>>>>>>>>>>>  drivers/net/can/m_can/Kconfig          |  13 +-
>>>>>>>>>>>  drivers/net/can/m_can/Makefile         |   1 +
>>>>>>>>>>>  drivers/net/can/m_can/m_can.c          | 700 +++++++++++++------------
>>>>>>>>>>>  drivers/net/can/m_can/m_can.h          | 110 ++++
>>>>>>>>>>>  drivers/net/can/m_can/m_can_platform.c | 202 +++++++
>>>>>>>>>>>  5 files changed, 682 insertions(+), 344 deletions(-)
>>>>>>>>>>>  create mode 100644 drivers/net/can/m_can/m_can.h
>>>>>>>>>>>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
>>>>>>>>>>>
>>>>>>>>>>> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
>>>>>>>>>>> index 04f20dd39007..f7119fd72df4 100644
>>>>>>>>>>> --- a/drivers/net/can/m_can/Kconfig
>>>>>>>>>>> +++ b/drivers/net/can/m_can/Kconfig
>>>>>>>>>>> @@ -1,5 +1,14 @@
>>>>>>>>>>>  config CAN_M_CAN
>>>>>>>>>>> +	tristate "Bosch M_CAN support"
>>>>>>>>>>> +	---help---
>>>>>>>>>>> +	  Say Y here if you want support for Bosch M_CAN controller framework.
>>>>>>>>>>> +	  This is common support for devices that embed the Bosch M_CAN IP.
>>>>>>>>>>> +
>>>>>>>>>>> +config CAN_M_CAN_PLATFORM
>>>>>>>>>>> +	tristate "Bosch M_CAN support for io-mapped devices"
>>>>>>>>>>>  	depends on HAS_IOMEM
>>>>>>>>>>> -	tristate "Bosch M_CAN devices"
>>>>>>>>>>> +	depends on CAN_M_CAN
>>>>>>>>>>>  	---help---
>>>>>>>>>>> -	  Say Y here if you want to support for Bosch M_CAN controller.
>>>>>>>>>>> +	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>>>>>>>>>>> +	  This support is for devices that have the Bosch M_CAN controller
>>>>>>>>>>> +	  IP embedded into the device and the IP is IO Mapped to the processor.
>>>>>>>>>>> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
>>>>>>>>>>> index 8bbd7f24f5be..057bbcdb3c74 100644
>>>>>>>>>>> --- a/drivers/net/can/m_can/Makefile
>>>>>>>>>>> +++ b/drivers/net/can/m_can/Makefile
>>>>>>>>>>> @@ -3,3 +3,4 @@
>>>>>>>>>>>  #
>>>>>>>>>>>  
>>>>>>>>>>>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
>>>>>>>>>>> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
>>>>>>>>>>> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
>>>>>>>>>>> index 9b449400376b..a60278d94126 100644
>>>>>>>>>>> --- a/drivers/net/can/m_can/m_can.c
>>>>>>>>>>> +++ b/drivers/net/can/m_can/m_can.c
>>>>>>>>>>
>>>>>>>>>> ... snip...
>>>>>>>>>>
>>>>>>>>>>> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>>>>>>>>>>> +				    struct net_device *dev)
>>>>>>>>>>> +{
>>>>>>>>>>> +	struct m_can_priv *priv = netdev_priv(dev);
>>>>>>>>>>> +
>>>>>>>>>>> +	if (can_dropped_invalid_skb(dev, skb))
>>>>>>>>>>> +		return NETDEV_TX_OK;
>>>>>>>>>>> +
>>>>>>>>>>> +	if (priv->is_peripherial) {
>>>>>>>>>>> +		if (priv->tx_skb) {
>>>>>>>>>>> +			netdev_err(dev, "hard_xmit called while tx busy\n");
>>>>>>>>>>> +			return NETDEV_TX_BUSY;
>>>>>>>>>>> +		}
>>>>>>>>>>
>>>>>>>>>> The problem with that approach is, that the upper layer will try to
>>>>>>>>>> resubmit the current "skb" but not the previous "tx_skb". And the
>>>>>>>>>> previous "tx_skb" has not been freed yet. I would just drop and free the
>>>>>>>>>> skb and return NETDEV_TX_OK in m_can_tx_handler() for peripheral devices
>>>>>>>>>> (like can_dropped_invalid_skb() does).
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> OK.
>>>>>>>>>
>>>>>>>>> So would this also be a bug in the hi3110 and mcp251x drivers (line 521) as well because besides checking tx_length
>>>>>>>>> this is how these drivers are written.
>>>>>>>>
>>>>>>>> This is different. When entering the "start_xmit" routine, the previous
>>>>>>>> TX is still in progress. It will (hopefully) complete soon. Therefore
>>>>>>>> returning NETDEV_TX_BUSY is OK. The "start_xmit" routine will be
>>>>>>>> recalled soon with the same "skb". That scenario should/could also not
>>>>>>>> happen.
>>>>>>>
>>>>>>> In principle, this also applies to the m_can peripheral devices. If
>>>>>>> tx_skb is not NULL, the TX is still in progress and returning
>>>>>>> NETDEV_TX_BUSY is just fine.
>>>>>>>
>>>>>>>>
>>>>>>>> In contrast, in "m_can_tx_handler()", the skb could not be handled
>>>>>>>> because the FIFO is full. The "start_xmit" routine for peripheral
>>>>>>>> devices for that skb already returned NETDEV_TX_OK. Therefore the only
>>>>>>>> meaningful action is to drop the skb. Also this error should not happen
>>>>>>>> and if, something is going really wrong. Therefore I think, a
>>>>>>>> WARN_ONCE() would be even more appropriate. But that should be a
>>>>>>>> separate patch.
>>>>>>>
>>>>>>> But that's a different issue/error. The tx_skb cannot be processed in
>>>>>>> "m_can_tx_handler()". Either we drop it or we re-queue it (retry later).
>>>>>>>
>>>>>>
>>>>>> OK I am a bit confused on this.  Are you saying this is not an issue?
>>>>>> Or are you saying I need to check for tx_len like the other code?
>>>>>
>>>>> If you check for tx_skb in the "start_xmit" routine like the hi3110 and
>>>>> mcp251x, it will work the same way. But only, if the "tx_handler()" has
>>>>> fully processed the message. It simple means, the TX is still in
>>>>> progress and will complete soon. But in "m_can_tx_handler()" we return
>>>>> without handling the message! It will never be sent and freed. Or will
>>>>> the "m_can_tx_handler()" retry?
>>>>>
>>>>
>>>> I am not seeing where we are not handling the message in the m_can_tx_handler()
>>>
>>> static void m_can_tx_handler(struct m_can_classdev *priv)
>>> {
>>> 		...
>>> 		/* Check if FIFO full */
>>> 		if (m_can_tx_fifo_full(priv)) {
>>> 			/* This shouldn't happen */
>>> 			netif_stop_queue(dev);
>>> 			netdev_warn(dev,
>>> 				    "TX queue active although FIFO is full.");
>>> 			return;
>>> 		}
>>>
>>> We simply return here. When is the message (tx_skb) processed (sent or freed)?
>>> What happens with tx_skb?
>>>
>>
>> Are you sure you are looking at the right code?
>>
>> For patch version v7 I have the following
>>
>> 		/* Check if FIFO full */
>> 		if (m_can_tx_fifo_full(cdev)) {
>> 			/* This shouldn't happen */
>> 			netif_stop_queue(dev);
>> 			netdev_warn(dev,
>> 				    "TX queue active although FIFO is full.");
>> 			return NETDEV_TX_BUSY;
>> 		}
>>
>> Which is no change from the original source code.
> 
> I know,  but for the peripheral devices you have:
> 
>   static void m_can_tx_work_queue(struct work_struct *ws)
>   {
> 	struct m_can_priv *priv = container_of(ws, struct m_can_priv,
> 						tx_work);
> 	netdev_tx_t ret;
> 
> 	ret = m_can_tx_handler(priv);
> 	if (ret == NETDEV_TX_OK)
> 		priv->tx_skb = NULL;
>   }
> 
> What will happen with tx_skb if NETDEV_TX_BUSY? It has not been
> dropped/freed yet?
> 

OK I think I see the issue there.

I should probably add can_put_echo_skb if NETDEV_TX_BUSY and always NULL out the SKB.

This appears to be the way the other perp drivers do it as they just put and null the skb
regardless of the return of the handlers.

And clean is called when the BUS is off or coming out of suspend.

Dan

> Wolfgang.
> 


-- 
------------------
Dan Murphy

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v7 1/4] can: m_can: Create a m_can platform framework
  2019-03-08 20:36                     ` Dan Murphy
@ 2019-03-11 11:19                       ` Wolfgang Grandegger
  0 siblings, 0 replies; 18+ messages in thread
From: Wolfgang Grandegger @ 2019-03-11 11:19 UTC (permalink / raw)
  To: Dan Murphy, mkl, davem; +Cc: linux-can, netdev, linux-kernel

Hello Dan,

Am 08.03.19 um 21:36 schrieb Dan Murphy:
> On 3/8/19 12:06 PM, Wolfgang Grandegger wrote:
>>
>>
>> Am 08.03.19 um 18:52 schrieb Dan Murphy:
>>> On 3/8/19 11:40 AM, Wolfgang Grandegger wrote:
>>>> Hello Dan,
>>>>
>>>> Am 08.03.19 um 18:25 schrieb Dan Murphy:
>>>>> On 3/8/19 11:08 AM, Wolfgang Grandegger wrote:
>>>>>> Hello,
>>>>>>
>>>>>> Am 08.03.19 um 16:48 schrieb Dan Murphy:
>>>>>>> Wolfgang
>>>>>>>
>>>>>>> On 3/8/19 8:41 AM, Wolfgang Grandegger wrote:
>>>>>>>> Hello Dan,
>>>>>>>>
>>>>>>>> thinking more about it...
>>>>>>>>
>>>>>>>> Am 08.03.19 um 14:29 schrieb Wolfgang Grandegger:
>>>>>>>>> Hello Dan,
>>>>>>>>>
>>>>>>>>> Am 08.03.19 um 13:44 schrieb Dan Murphy:
>>>>>>>>>> Wolfgang
>>>>>>>>>>
>>>>>>>>>> On 3/8/19 4:10 AM, Wolfgang Grandegger wrote:
>>>>>>>>>>> Hallo Dan,
>>>>>>>>>>>
>>>>>>>>>>> Am 05.03.19 um 16:52 schrieb Dan Murphy:
>>>>>>>>>>>> Create a m_can platform framework that peripherial
>>>>>>>>>>>> devices can register to and use common code and register sets.
>>>>>>>>>>>> The peripherial devices may provide read/write and configuration
>>>>>>>>>>>> support of the IP.
>>>>>>>>>>>>
>>>>>>>>>>>> Signed-off-by: Dan Murphy <dmurphy@ti.com>
>>>>>>>>>>>> ---
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> v7 - Fixed remaining new checkpatch issues, removed CSR setting, fixed tx hard
>>>>>>>>>>>> start function to return tx_busy, and renamed device callbacks - https://lore.kernel.org/patchwork/patch/1047220/
>>>>>>>>>>>>
>>>>>>>>>>>> v6 - Squashed platform patch to this patch for bissectablity, fixed coding style
>>>>>>>>>>>> issues, updated Kconfig help, placed mcan reg offsets back into c file, renamed
>>>>>>>>>>>> priv->skb to priv->tx_skb and cleared perp interrupts at ISR start -
>>>>>>>>>>>> Patch 1 comments - https://lore.kernel.org/patchwork/patch/1042446/
>>>>>>>>>>>> Patch 2 comments - https://lore.kernel.org/patchwork/patch/1042442/
>>>>>>>>>>>>
>>>>>>>>>>>>  drivers/net/can/m_can/Kconfig          |  13 +-
>>>>>>>>>>>>  drivers/net/can/m_can/Makefile         |   1 +
>>>>>>>>>>>>  drivers/net/can/m_can/m_can.c          | 700 +++++++++++++------------
>>>>>>>>>>>>  drivers/net/can/m_can/m_can.h          | 110 ++++
>>>>>>>>>>>>  drivers/net/can/m_can/m_can_platform.c | 202 +++++++
>>>>>>>>>>>>  5 files changed, 682 insertions(+), 344 deletions(-)
>>>>>>>>>>>>  create mode 100644 drivers/net/can/m_can/m_can.h
>>>>>>>>>>>>  create mode 100644 drivers/net/can/m_can/m_can_platform.c
>>>>>>>>>>>>
>>>>>>>>>>>> diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
>>>>>>>>>>>> index 04f20dd39007..f7119fd72df4 100644
>>>>>>>>>>>> --- a/drivers/net/can/m_can/Kconfig
>>>>>>>>>>>> +++ b/drivers/net/can/m_can/Kconfig
>>>>>>>>>>>> @@ -1,5 +1,14 @@
>>>>>>>>>>>>  config CAN_M_CAN
>>>>>>>>>>>> +	tristate "Bosch M_CAN support"
>>>>>>>>>>>> +	---help---
>>>>>>>>>>>> +	  Say Y here if you want support for Bosch M_CAN controller framework.
>>>>>>>>>>>> +	  This is common support for devices that embed the Bosch M_CAN IP.
>>>>>>>>>>>> +
>>>>>>>>>>>> +config CAN_M_CAN_PLATFORM
>>>>>>>>>>>> +	tristate "Bosch M_CAN support for io-mapped devices"
>>>>>>>>>>>>  	depends on HAS_IOMEM
>>>>>>>>>>>> -	tristate "Bosch M_CAN devices"
>>>>>>>>>>>> +	depends on CAN_M_CAN
>>>>>>>>>>>>  	---help---
>>>>>>>>>>>> -	  Say Y here if you want to support for Bosch M_CAN controller.
>>>>>>>>>>>> +	  Say Y here if you want support for IO Mapped Bosch M_CAN controller.
>>>>>>>>>>>> +	  This support is for devices that have the Bosch M_CAN controller
>>>>>>>>>>>> +	  IP embedded into the device and the IP is IO Mapped to the processor.
>>>>>>>>>>>> diff --git a/drivers/net/can/m_can/Makefile b/drivers/net/can/m_can/Makefile
>>>>>>>>>>>> index 8bbd7f24f5be..057bbcdb3c74 100644
>>>>>>>>>>>> --- a/drivers/net/can/m_can/Makefile
>>>>>>>>>>>> +++ b/drivers/net/can/m_can/Makefile
>>>>>>>>>>>> @@ -3,3 +3,4 @@
>>>>>>>>>>>>  #
>>>>>>>>>>>>  
>>>>>>>>>>>>  obj-$(CONFIG_CAN_M_CAN) += m_can.o
>>>>>>>>>>>> +obj-$(CONFIG_CAN_M_CAN_PLATFORM) += m_can_platform.o
>>>>>>>>>>>> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
>>>>>>>>>>>> index 9b449400376b..a60278d94126 100644
>>>>>>>>>>>> --- a/drivers/net/can/m_can/m_can.c
>>>>>>>>>>>> +++ b/drivers/net/can/m_can/m_can.c
>>>>>>>>>>>
>>>>>>>>>>> ... snip...
>>>>>>>>>>>
>>>>>>>>>>>> +static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
>>>>>>>>>>>> +				    struct net_device *dev)
>>>>>>>>>>>> +{
>>>>>>>>>>>> +	struct m_can_priv *priv = netdev_priv(dev);
>>>>>>>>>>>> +
>>>>>>>>>>>> +	if (can_dropped_invalid_skb(dev, skb))
>>>>>>>>>>>> +		return NETDEV_TX_OK;
>>>>>>>>>>>> +
>>>>>>>>>>>> +	if (priv->is_peripherial) {
>>>>>>>>>>>> +		if (priv->tx_skb) {
>>>>>>>>>>>> +			netdev_err(dev, "hard_xmit called while tx busy\n");
>>>>>>>>>>>> +			return NETDEV_TX_BUSY;
>>>>>>>>>>>> +		}
>>>>>>>>>>>
>>>>>>>>>>> The problem with that approach is, that the upper layer will try to
>>>>>>>>>>> resubmit the current "skb" but not the previous "tx_skb". And the
>>>>>>>>>>> previous "tx_skb" has not been freed yet. I would just drop and free the
>>>>>>>>>>> skb and return NETDEV_TX_OK in m_can_tx_handler() for peripheral devices
>>>>>>>>>>> (like can_dropped_invalid_skb() does).
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> OK.
>>>>>>>>>>
>>>>>>>>>> So would this also be a bug in the hi3110 and mcp251x drivers (line 521) as well because besides checking tx_length
>>>>>>>>>> this is how these drivers are written.
>>>>>>>>>
>>>>>>>>> This is different. When entering the "start_xmit" routine, the previous
>>>>>>>>> TX is still in progress. It will (hopefully) complete soon. Therefore
>>>>>>>>> returning NETDEV_TX_BUSY is OK. The "start_xmit" routine will be
>>>>>>>>> recalled soon with the same "skb". That scenario should/could also not
>>>>>>>>> happen.
>>>>>>>>
>>>>>>>> In principle, this also applies to the m_can peripheral devices. If
>>>>>>>> tx_skb is not NULL, the TX is still in progress and returning
>>>>>>>> NETDEV_TX_BUSY is just fine.
>>>>>>>>
>>>>>>>>>
>>>>>>>>> In contrast, in "m_can_tx_handler()", the skb could not be handled
>>>>>>>>> because the FIFO is full. The "start_xmit" routine for peripheral
>>>>>>>>> devices for that skb already returned NETDEV_TX_OK. Therefore the only
>>>>>>>>> meaningful action is to drop the skb. Also this error should not happen
>>>>>>>>> and if, something is going really wrong. Therefore I think, a
>>>>>>>>> WARN_ONCE() would be even more appropriate. But that should be a
>>>>>>>>> separate patch.
>>>>>>>>
>>>>>>>> But that's a different issue/error. The tx_skb cannot be processed in
>>>>>>>> "m_can_tx_handler()". Either we drop it or we re-queue it (retry later).
>>>>>>>>
>>>>>>>
>>>>>>> OK I am a bit confused on this.  Are you saying this is not an issue?
>>>>>>> Or are you saying I need to check for tx_len like the other code?
>>>>>>
>>>>>> If you check for tx_skb in the "start_xmit" routine like the hi3110 and
>>>>>> mcp251x, it will work the same way. But only, if the "tx_handler()" has
>>>>>> fully processed the message. It simple means, the TX is still in
>>>>>> progress and will complete soon. But in "m_can_tx_handler()" we return
>>>>>> without handling the message! It will never be sent and freed. Or will
>>>>>> the "m_can_tx_handler()" retry?
>>>>>>
>>>>>
>>>>> I am not seeing where we are not handling the message in the m_can_tx_handler()
>>>>
>>>> static void m_can_tx_handler(struct m_can_classdev *priv)
>>>> {
>>>> 		...
>>>> 		/* Check if FIFO full */
>>>> 		if (m_can_tx_fifo_full(priv)) {
>>>> 			/* This shouldn't happen */
>>>> 			netif_stop_queue(dev);
>>>> 			netdev_warn(dev,
>>>> 				    "TX queue active although FIFO is full.");
>>>> 			return;
>>>> 		}
>>>>
>>>> We simply return here. When is the message (tx_skb) processed (sent or freed)?
>>>> What happens with tx_skb?
>>>>
>>>
>>> Are you sure you are looking at the right code?
>>>
>>> For patch version v7 I have the following
>>>
>>> 		/* Check if FIFO full */
>>> 		if (m_can_tx_fifo_full(cdev)) {
>>> 			/* This shouldn't happen */
>>> 			netif_stop_queue(dev);
>>> 			netdev_warn(dev,
>>> 				    "TX queue active although FIFO is full.");
>>> 			return NETDEV_TX_BUSY;
>>> 		}
>>>
>>> Which is no change from the original source code.
>>
>> I know,  but for the peripheral devices you have:
>>
>>   static void m_can_tx_work_queue(struct work_struct *ws)
>>   {
>> 	struct m_can_priv *priv = container_of(ws, struct m_can_priv,
>> 						tx_work);
>> 	netdev_tx_t ret;
>>
>> 	ret = m_can_tx_handler(priv);
>> 	if (ret == NETDEV_TX_OK)
>> 		priv->tx_skb = NULL;
>>   }
>>
>> What will happen with tx_skb if NETDEV_TX_BUSY? It has not been
>> dropped/freed yet?
>>
> 
> OK I think I see the issue there.

The key point is that the "skb" entered by the "start_xmit" must be
released/free when it's processed (with NETDEV_TX_OK). This is more
tricky for perp devices because the "skb" is handled deferred.

> 
> I should probably add can_put_echo_skb if NETDEV_TX_BUSY and always NULL out the SKB.

can_put_echo_skb() should only be called after the TX has been
initiated. The normal flow for the skb is:

 start-xmit -> initiate tx -> can_put_echo_skb -> return NETDEV_TX_OK...
   tx done interrupt -> can_get_echo_skb -> free skb

I would just drop the message/skb:

		/* Check if FIFO full */
		if (m_can_tx_fifo_full(cdev)) {
			/* This shouldn't happen */
			netif_stop_queue(dev);
			netdev_warn(dev,
				    "TX queue active although FIFO is full.");
			if (cdev->is_peripherial) {
				kfree_skb(skb);
				dev->stats.tx_dropped++;
				return NETDEV_TX_OK;
			} else {
				return NETDEV_TX_BUSY;
			}
		}

> This appears to be the way the other perp drivers do it as they just put and null the skb
> regardless of the return of the handlers.

You can also use:

		if (cdev->tx_skb) {
			netdev_err(dev, "hard_xmit called while tx busy\n");
			return NETDEV_TX_BUSY;
		}

to check for "hard_xmit called while tx busy". But you still need to
handle the "m_can_tx_fifo_full(cdev)" case properly. See above.

> And clean is called when the BUS is off or coming out of suspend.

Probably we need that as well even if other drivers don't care if
the device goes bus-off while TX messages are pending.

Wolfgang

^ permalink raw reply	[flat|nested] 18+ messages in thread

end of thread, other threads:[~2019-03-11 11:20 UTC | newest]

Thread overview: 18+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-05 15:52 [PATCH v7 1/4] can: m_can: Create a m_can platform framework Dan Murphy
2019-03-05 15:52 ` [PATCH v7 2/4] can: m_can: Rename m_can_priv to m_can_classdev Dan Murphy
2019-03-08 10:25   ` Wolfgang Grandegger
2019-03-08 12:33     ` Dan Murphy
2019-03-05 15:52 ` [PATCH v7 3/4] dt-bindings: can: tcan4x5x: Add DT bindings for TCAN4x5X driver Dan Murphy
2019-03-05 15:52 ` [PATCH v7 4/4] can: tcan4x5x: Add tcan4x5x driver to the kernel Dan Murphy
2019-03-08 10:10 ` [PATCH v7 1/4] can: m_can: Create a m_can platform framework Wolfgang Grandegger
2019-03-08 12:44   ` Dan Murphy
2019-03-08 13:29     ` Wolfgang Grandegger
2019-03-08 14:41       ` Wolfgang Grandegger
2019-03-08 15:48         ` Dan Murphy
2019-03-08 17:08           ` Wolfgang Grandegger
2019-03-08 17:25             ` Dan Murphy
2019-03-08 17:40               ` Wolfgang Grandegger
2019-03-08 17:52                 ` Dan Murphy
2019-03-08 18:06                   ` Wolfgang Grandegger
2019-03-08 20:36                     ` Dan Murphy
2019-03-11 11:19                       ` Wolfgang Grandegger

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