[PATCH 5/5] can: flexcan: add mcf5441x support

[Angelo Dureghello <angelo@kernel-space.org>]

Add flexcan support for NXP ColdFire mcf5441x family.

This flexcan module is quite similar to imx6 flexcan module, but
with some exceptions:

- 3 separate interrupt sources, MB, BOFF and ERR,
- implements 16 mb only,
- m68k architecture is not supporting devicetrees, so a
  platform data check/case has been added,
- ColdFire is m68k, so big-endian cpu, with a little-endian flexcan
  module.

Signed-off-by: Angelo Dureghello <angelo@kernel-space.org>
---
 drivers/net/can/flexcan.c | 80 +++++++++++++++++++++++++++++++--------
 1 file changed, 65 insertions(+), 15 deletions(-)

diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 57f3635ad8d7..af95273327cd 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -28,6 +28,7 @@
 #include <linux/of_device.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
+#include <linux/platform_data/flexcan-mcf.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
@@ -205,6 +206,10 @@
 
 #define FLEXCAN_TIMEOUT_US		(250)
 
+#define FLEXCAN_OFFS_INT_BOFF		1
+#define FLEXCAN_OFFS_INT_ERR		3
+#define FLEXCAN_MB_CNT_MCF		16
+
 /* FLEXCAN hardware feature flags
  *
  * Below is some version info we got:
@@ -246,6 +251,8 @@
 #define FLEXCAN_QUIRK_SUPPORT_ECC BIT(10)
 /* Setup stop mode with SCU firmware to support wakeup */
 #define FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW BIT(11)
+/* Setup for flexcan module as in mcf, 16 mb, 3 separate interrupts  */
+#define FLEXCAN_QUIRK_SETUP_MCF BIT(12)
 
 /* Structure of the message buffer */
 struct flexcan_mb {
@@ -371,6 +378,12 @@ struct flexcan_priv {
 	void (*write)(u32 val, void __iomem *addr);
 };
 
+static const struct flexcan_devtype_data fsl_mcf_devtype_data = {
+	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
+		FLEXCAN_QUIRK_BROKEN_PERR_STATE |
+		FLEXCAN_QUIRK_SETUP_MCF,
+};
+
 static const struct flexcan_devtype_data fsl_p1010_devtype_data = {
 	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
 		FLEXCAN_QUIRK_BROKEN_PERR_STATE |
@@ -637,13 +650,17 @@ static int flexcan_clks_enable(const struct flexcan_priv *priv)
 {
 	int err;
 
-	err = clk_prepare_enable(priv->clk_ipg);
-	if (err)
-		return err;
+	if (priv->clk_ipg) {
+		err = clk_prepare_enable(priv->clk_ipg);
+		if (err)
+			return err;
+	}
 
-	err = clk_prepare_enable(priv->clk_per);
-	if (err)
-		clk_disable_unprepare(priv->clk_ipg);
+	if (priv->clk_per) {
+		err = clk_prepare_enable(priv->clk_per);
+		if (err)
+			clk_disable_unprepare(priv->clk_ipg);
+	}
 
 	return err;
 }
@@ -1401,8 +1418,13 @@ static int flexcan_rx_offload_setup(struct net_device *dev)
 		priv->mb_size = sizeof(struct flexcan_mb) + CANFD_MAX_DLEN;
 	else
 		priv->mb_size = sizeof(struct flexcan_mb) + CAN_MAX_DLEN;
-	priv->mb_count = (sizeof(priv->regs->mb[0]) / priv->mb_size) +
-			 (sizeof(priv->regs->mb[1]) / priv->mb_size);
+
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_MCF) {
+		priv->mb_count = FLEXCAN_MB_CNT_MCF;
+	} else {
+		priv->mb_count = (sizeof(priv->regs->mb[0]) / priv->mb_size) +
+				 (sizeof(priv->regs->mb[1]) / priv->mb_size);
+	}
 
 	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
 		priv->tx_mb_reserved =
@@ -1774,6 +1796,18 @@ static int flexcan_open(struct net_device *dev)
 	if (err)
 		goto out_can_rx_offload_disable;
 
+	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_MCF) {
+		err = request_irq(dev->irq + FLEXCAN_OFFS_INT_BOFF,
+				  flexcan_irq, IRQF_SHARED, dev->name, dev);
+		if (err)
+			goto out_can_rx_offload_disable;
+
+		err = request_irq(dev->irq + FLEXCAN_OFFS_INT_ERR,
+				  flexcan_irq, IRQF_SHARED, dev->name, dev);
+		if (err)
+			goto out_can_rx_offload_disable;
+	}
+
 	flexcan_chip_interrupts_enable(dev);
 
 	can_led_event(dev, CAN_LED_EVENT_OPEN);
@@ -2047,7 +2081,9 @@ static int flexcan_probe(struct platform_device *pdev)
 	struct regulator *reg_xceiver;
 	struct clk *clk_ipg = NULL, *clk_per = NULL;
 	struct flexcan_regs __iomem *regs;
+	struct mcf_flexcan_platform_data *pdata;
 	int err, irq;
+	bool big_endian_module;
 	u8 clk_src = 1;
 	u32 clock_freq = 0;
 
@@ -2059,11 +2095,17 @@ static int flexcan_probe(struct platform_device *pdev)
 	else if (IS_ERR(reg_xceiver))
 		return PTR_ERR(reg_xceiver);
 
-	if (pdev->dev.of_node) {
-		of_property_read_u32(pdev->dev.of_node,
-				     "clock-frequency", &clock_freq);
-		of_property_read_u8(pdev->dev.of_node,
-				    "fsl,clk-source", &clk_src);
+	pdata = dev_get_platdata(&pdev->dev);
+	if (pdata) {
+		clock_freq = pdata->clock_frequency;
+		clk_src = pdata->clk_src;
+	} else {
+		if (pdev->dev.of_node) {
+			of_property_read_u32(pdev->dev.of_node,
+					     "clock-frequency", &clock_freq);
+			of_property_read_u8(pdev->dev.of_node,
+					    "fsl,clk-source", &clk_src);
+		}
 	}
 
 	if (!clock_freq) {
@@ -2091,6 +2133,11 @@ static int flexcan_probe(struct platform_device *pdev)
 
 	devtype_data = of_device_get_match_data(&pdev->dev);
 
+	if (pdata && !devtype_data) {
+		devtype_data =
+			(struct flexcan_devtype_data *)&fsl_mcf_devtype_data;
+	}
+
 	if ((devtype_data->quirks & FLEXCAN_QUIRK_SUPPORT_FD) &&
 	    !(devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)) {
 		dev_err(&pdev->dev, "CAN-FD mode doesn't work with FIFO mode!\n");
@@ -2110,8 +2157,11 @@ static int flexcan_probe(struct platform_device *pdev)
 
 	priv = netdev_priv(dev);
 
-	if (of_property_read_bool(pdev->dev.of_node, "big-endian") ||
-	    devtype_data->quirks & FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN) {
+	big_endian_module = pdata ? pdata->big_endian :
+		of_property_read_bool(pdev->dev.of_node, "big-endian");
+
+	if (big_endian_module ||
+		(devtype_data->quirks & FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN)) {
 		priv->read = flexcan_read_be;
 		priv->write = flexcan_write_be;
 	} else {
-- 
2.31.1