* [PATCH v8 0/3] i2c: npcm: add NPCM i2c controller driver
@ 2020-03-01 22:31 Tali Perry
2020-03-01 22:31 ` [PATCH v8 1/3] dt-bindings: i2c: npcm7xx: add NPCM I2C controller Tali Perry
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Tali Perry @ 2020-03-01 22:31 UTC (permalink / raw)
To: brendanhiggins, avifishman70, tmaimon77, kfting, venture, yuenn,
benjaminfair, robh+dt, wsa, andriy.shevchenko
Cc: linux-arm-kernel, linux-i2c, openbmc, devicetree, linux-kernel,
Tali Perry, Rob Herring, kbuild test robot
This patch set adds i2c controller support
for the Nuvoton NPCM Baseboard Management Controller (BMC).
NPCM7xx includes 16 I2C controllers. This driver operates the controller.
This module also includes a slave mode.
---
v8 -> v7:
- Split to two commits, one for master, one for slave.
- Rename smb to i2c.
- Remove global vars.
v7 -> v6:
- Rebased on Linux 5.4-rc8 (was Linux 5.4-rc7).
- Fix issue found by kbuild test robot (redundant include).
- Note: left a warning related to fall through. This fall through is
intentional.
v6 -> v5:
- Update documentation
v5 -> v4:
- support recovery
- master-slave switch support needed for IPMB
v4 -> v3:
- typo on cover letter.
v3 -> v2:
- fix dt binding: compatible name: omit "bus"
v2 -> v1:
- run check patch in strict mode.
- use linux crc.
- define regs in constant offset without base.
- remove debug prints.
- no declarations for local functions.
v1: initial version
Signed-off-by: Tali Perry <tali.perry1@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reported-by: kbuild test robot <lkp@intel.com>
---
Tali Perry (3):
dt-bindings: i2c: npcm7xx: add NPCM I2C controller documentation
i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver
i2c: npcm7xx: Add support for slave mode for Nuvoton NPCM BMC I2C
controller driver.
.../devicetree/bindings/i2c/i2c-npcm7xx.txt | 29 +
drivers/i2c/busses/Kconfig | 9 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-npcm7xx.c | 2490 +++++++++++++++++
4 files changed, 2529 insertions(+)
create mode 100644 Documentation/devicetree/bindings/i2c/i2c-npcm7xx.txt
create mode 100644 drivers/i2c/busses/i2c-npcm7xx.c
base-commit: af42d3466bdc8f39806b26f593604fdc54140bcb
--
2.22.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH v8 1/3] dt-bindings: i2c: npcm7xx: add NPCM I2C controller
2020-03-01 22:31 [PATCH v8 0/3] i2c: npcm: add NPCM i2c controller driver Tali Perry
@ 2020-03-01 22:31 ` Tali Perry
2020-03-01 22:32 ` [PATCH v8 2/3] i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver Tali Perry
2020-03-01 22:32 ` [PATCH v8 3/3] i2c: npcm7xx: Add support for slave mode for Nuvoton Tali Perry
2 siblings, 0 replies; 5+ messages in thread
From: Tali Perry @ 2020-03-01 22:31 UTC (permalink / raw)
To: brendanhiggins, avifishman70, tmaimon77, kfting, venture, yuenn,
benjaminfair, robh+dt, wsa, andriy.shevchenko
Cc: linux-arm-kernel, linux-i2c, openbmc, devicetree, linux-kernel,
Tali Perry, Rob Herring
Added device tree binding documentation for Nuvoton BMC
NPCM I2C controller.
Signed-off-by: Tali Perry <tali.perry1@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
.../devicetree/bindings/i2c/i2c-npcm7xx.txt | 29 +++++++++++++++++++
1 file changed, 29 insertions(+)
create mode 100644 Documentation/devicetree/bindings/i2c/i2c-npcm7xx.txt
diff --git a/Documentation/devicetree/bindings/i2c/i2c-npcm7xx.txt b/Documentation/devicetree/bindings/i2c/i2c-npcm7xx.txt
new file mode 100644
index 000000000000..0ecae950748b
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-npcm7xx.txt
@@ -0,0 +1,29 @@
+Nuvoton NPCM7XX I2C bus
+
+The NPCM750x includes sixteen I2C bus controllers. All Controllers support
+both master and slave mode. Each controller has two 16 byte HW FIFO for TX and
+RX.
+
+Required properties:
+- compatible : must be "nuvoton,npcm750-i2c"
+- reg : Offset and length of the register set for the device.
+- interrupts : Contain the I2C interrupt with flags for falling edge.
+- clocks : phandle of I2C reference clock.
+
+Optional:
+- bus-frequency : Contain the I2C bus frequency,
+ the default I2C bus frequency is 100000.
+- pinctrl-0 : for example <&smbX_pins>, X is module number
+ (on NPCM7XX it's 0 to 15)
+- pinctrl-names : should be set to "default"
+Example:
+
+ i2c0: i2c@80000 {
+ compatible = "nuvoton,npcm750-i2c";
+ reg = <0x80000 0x1000>;
+ clocks = <&clk NPCM7XX_CLK_APB2>;
+ bus-frequency = <100000>;
+ interrupts = <GIC_SPI 64 IRQ_TYPE_LEVEL_HIGH>;
+ pinctrl-names = "default";
+ pinctrl-0 = <&smb0_pins>;
+ };
--
2.22.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v8 2/3] i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver
2020-03-01 22:31 [PATCH v8 0/3] i2c: npcm: add NPCM i2c controller driver Tali Perry
2020-03-01 22:31 ` [PATCH v8 1/3] dt-bindings: i2c: npcm7xx: add NPCM I2C controller Tali Perry
@ 2020-03-01 22:32 ` Tali Perry
2020-03-02 10:50 ` Andy Shevchenko
2020-03-01 22:32 ` [PATCH v8 3/3] i2c: npcm7xx: Add support for slave mode for Nuvoton Tali Perry
2 siblings, 1 reply; 5+ messages in thread
From: Tali Perry @ 2020-03-01 22:32 UTC (permalink / raw)
To: brendanhiggins, avifishman70, tmaimon77, kfting, venture, yuenn,
benjaminfair, robh+dt, wsa, andriy.shevchenko
Cc: linux-arm-kernel, linux-i2c, openbmc, devicetree, linux-kernel,
Tali Perry
Add Nuvoton NPCM BMC I2C controller driver.
Signed-off-by: Tali Perry <tali.perry1@gmail.com>
---
drivers/i2c/busses/Kconfig | 9 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-npcm7xx.c | 1888 ++++++++++++++++++++++++++++++
3 files changed, 1898 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-npcm7xx.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 146ce40d8e0a..833349971260 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -786,6 +786,15 @@ config I2C_NOMADIK
I2C interface from ST-Ericsson's Nomadik and Ux500 architectures,
as well as the STA2X11 PCIe I/O HUB.
+config I2C_NPCM7XX
+ tristate "Nuvoton I2C Controller"
+ depends on ARCH_NPCM7XX || COMPILE_TEST
+ help
+ If you say yes to this option, support will be included for the
+ Nuvoton I2C controller, which is available on the NPCM7xx BMC
+ controller.
+ Driver can also support slave mode (select I2C_SLAVE).
+
config I2C_OCORES
tristate "OpenCores I2C Controller"
help
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 3ab8aebc39c9..4af59a806f3c 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -81,6 +81,7 @@ obj-$(CONFIG_I2C_MT7621) += i2c-mt7621.o
obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o
obj-$(CONFIG_I2C_MXS) += i2c-mxs.o
obj-$(CONFIG_I2C_NOMADIK) += i2c-nomadik.o
+obj-$(CONFIG_I2C_NPCM7XX) += i2c-npcm7xx.o
obj-$(CONFIG_I2C_OCORES) += i2c-ocores.o
obj-$(CONFIG_I2C_OMAP) += i2c-omap.o
obj-$(CONFIG_I2C_OWL) += i2c-owl.o
diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
new file mode 100644
index 000000000000..cef5288f0394
--- /dev/null
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -0,0 +1,1888 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NPCM7xx I2C Controller driver
+ *
+ * Copyright (C) 2020 Nuvoton Technologies tali.perry@nuvoton.com
+ */
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/jiffies.h>
+
+enum i2c_mode {
+ I2C_MASTER,
+ I2C_SLAVE
+};
+
+/*
+ * External I2C Interface driver xfer indication values, which indicate status
+ * of the bus.
+ */
+enum i2c_state_ind {
+ I2C_NO_STATUS_IND = 0,
+ I2C_SLAVE_RCV_IND = 1,
+ I2C_SLAVE_XMIT_IND = 2,
+ I2C_SLAVE_XMIT_MISSING_DATA_IND = 3,
+ I2C_SLAVE_RESTART_IND = 4,
+ I2C_SLAVE_DONE_IND = 5,
+ I2C_MASTER_DONE_IND = 6,
+ I2C_NACK_IND = 8,
+ I2C_BUS_ERR_IND = 9,
+ I2C_WAKE_UP_IND = 10,
+ I2C_BLOCK_BYTES_ERR_IND = 12,
+ I2C_SLAVE_RCV_MISSING_DATA_IND = 14,
+};
+
+// I2Cus Operation type values
+enum i2c_oper {
+ I2C_NO_OPER = 0,
+ I2C_WRITE_OPER = 1,
+ I2C_READ_OPER = 2
+};
+
+// I2Cus Bank (FIFO mode)
+enum i2c_bank {
+ I2C_BANK_0 = 0,
+ I2C_BANK_1 = 1
+};
+
+// Internal I2C states values (for the I2C module state machine).
+enum i2c_state {
+ I2C_DISABLE = 0,
+ I2C_IDLE,
+ I2C_MASTER_START,
+ I2C_SLAVE_MATCH,
+ I2C_OPER_STARTED,
+ I2C_STOP_PENDING
+};
+
+// init register and default value required to enable module
+#define NPCM_I2CSEGCTL 0xE4
+#define I2CSEGCTL_VAL 0x0333F000
+
+// Common regs
+#define NPCM_I2CSDA 0x00
+#define NPCM_I2CST 0x02
+#define NPCM_I2CCST 0x04
+#define NPCM_I2CCTL1 0x06
+#define NPCM_I2CADDR1 0x08
+#define NPCM_I2CCTL2 0x0A
+#define NPCM_I2CADDR2 0x0C
+#define NPCM_I2CCTL3 0x0E
+#define NPCM_I2CCST2 0x18
+#define NPCM_I2CCST3 0x19
+#define I2C_VER 0x1F
+
+// BANK 0 regs
+#define NPCM_I2CADDR3 0x10
+#define NPCM_I2CADDR7 0x11
+#define NPCM_I2CADDR4 0x12
+#define NPCM_I2CADDR8 0x13
+#define NPCM_I2CADDR5 0x14
+#define NPCM_I2CADDR9 0x15
+#define NPCM_I2CADDR6 0x16
+#define NPCM_I2CADDR10 0x17
+
+#define NPCM_I2CCTL4 0x1A
+#define NPCM_I2CCTL5 0x1B
+#define NPCM_I2CSCLLT 0x1C // SCL Low Time
+#define NPCM_I2CFIF_CTL 0x1D // FIFO Control
+#define NPCM_I2CSCLHT 0x1E // SCL High Time
+
+// BANK 1 regs
+#define NPCM_I2CFIF_CTS 0x10 // Both FIFOs Control and status
+#define NPCM_I2CTXF_CTL 0x12 // Tx-FIFO Control
+#define NPCM_I2CT_OUT 0x14 // Bus T.O.
+#define NPCM_I2CPEC 0x16 // PEC Data
+#define NPCM_I2CTXF_STS 0x1A // Tx-FIFO Status
+#define NPCM_I2CRXF_STS 0x1C // Rx-FIFO Status
+#define NPCM_I2CRXF_CTL 0x1E // Rx-FIFO Control
+
+// NPCM_I2CST reg fields
+#define NPCM_I2CST_XMIT BIT(0)
+#define NPCM_I2CST_MASTER BIT(1)
+#define NPCM_I2CST_NMATCH BIT(2)
+#define NPCM_I2CST_STASTR BIT(3)
+#define NPCM_I2CST_NEGACK BIT(4)
+#define NPCM_I2CST_BER BIT(5)
+#define NPCM_I2CST_SDAST BIT(6)
+#define NPCM_I2CST_SLVSTP BIT(7)
+
+// NPCM_I2CCST reg fields
+#define NPCM_I2CCST_BUSY BIT(0)
+#define NPCM_I2CCST_BB BIT(1)
+#define NPCM_I2CCST_MATCH BIT(2)
+#define NPCM_I2CCST_GCMATCH BIT(3)
+#define NPCM_I2CCST_TSDA BIT(4)
+#define NPCM_I2CCST_TGSCL BIT(5)
+#define NPCM_I2CCST_MATCHAF BIT(6)
+#define NPCM_I2CCST_ARPMATCH BIT(7)
+
+// NPCM_I2CCTL1 reg fields
+#define NPCM_I2CCTL1_START BIT(0)
+#define NPCM_I2CCTL1_STOP BIT(1)
+#define NPCM_I2CCTL1_INTEN BIT(2)
+#define NPCM_I2CCTL1_EOBINTE BIT(3)
+#define NPCM_I2CCTL1_ACK BIT(4)
+#define NPCM_I2CCTL1_GCMEN BIT(5)
+#define NPCM_I2CCTL1_NMINTE BIT(6)
+#define NPCM_I2CCTL1_STASTRE BIT(7)
+
+// RW1S fields (inside a RW reg):
+#define NPCM_I2CCTL1_RWS_FIELDS (NPCM_I2CCTL1_START | NPCM_I2CCTL1_STOP | \
+ NPCM_I2CCTL1_ACK)
+
+// npcm_i2caddr reg fields
+#define NPCM_I2CADDR_A GENMASK(6, 0)
+#define NPCM_I2CADDR_SAEN BIT(7)
+
+// NPCM_I2CCTL2 reg fields
+#define I2CCTL2_ENABLE BIT(0)
+#define I2CCTL2_SCLFRQ6_0 GENMASK(7, 1)
+
+// NPCM_I2CCTL3 reg fields
+#define I2CCTL3_SCLFRQ8_7 GENMASK(1, 0)
+#define I2CCTL3_ARPMEN BIT(2)
+#define I2CCTL3_IDL_START BIT(3)
+#define I2CCTL3_400K_MODE BIT(4)
+#define I2CCTL3_BNK_SEL BIT(5)
+#define I2CCTL3_SDA_LVL BIT(6)
+#define I2CCTL3_SCL_LVL BIT(7)
+
+// NPCM_I2CCST2 reg fields
+#define NPCM_I2CCST2_MATCHA1F BIT(0)
+#define NPCM_I2CCST2_MATCHA2F BIT(1)
+#define NPCM_I2CCST2_MATCHA3F BIT(2)
+#define NPCM_I2CCST2_MATCHA4F BIT(3)
+#define NPCM_I2CCST2_MATCHA5F BIT(4)
+#define NPCM_I2CCST2_MATCHA6F BIT(5)
+#define NPCM_I2CCST2_MATCHA7F BIT(5)
+#define NPCM_I2CCST2_INTSTS BIT(7)
+
+// NPCM_I2CCST3 reg fields
+#define NPCM_I2CCST3_MATCHA8F BIT(0)
+#define NPCM_I2CCST3_MATCHA9F BIT(1)
+#define NPCM_I2CCST3_MATCHA10F BIT(2)
+#define NPCM_I2CCST3_EO_BUSY BIT(7)
+
+// NPCM_I2CCTL4 reg fields
+#define I2CCTL4_HLDT GENMASK(5, 0)
+#define I2CCTL4_LVL_WE BIT(7)
+
+// NPCM_I2CCTL5 reg fields
+#define I2CCTL5_DBNCT GENMASK(3, 0)
+
+// NPCM_I2CFIF_CTS reg fields
+#define NPCM_I2CFIF_CTS_RXF_TXE BIT(1)
+#define NPCM_I2CFIF_CTS_RFTE_IE BIT(3)
+#define NPCM_I2CFIF_CTS_CLR_FIFO BIT(6)
+#define NPCM_I2CFIF_CTS_SLVRSTR BIT(7)
+
+// NPCM_I2CTXF_CTL reg fields
+#define NPCM_I2CTXF_CTL_TX_THR GENMASK(4, 0)
+#define NPCM_I2CTXF_CTL_THR_TXIE BIT(6)
+
+// NPCM_I2CT_OUT reg fields
+#define NPCM_I2CT_OUT_TO_CKDIV GENMASK(5, 0)
+#define NPCM_I2CT_OUT_T_OUTIE BIT(6)
+#define NPCM_I2CT_OUT_T_OUTST BIT(7)
+
+// NPCM_I2CTXF_STS reg fields
+#define NPCM_I2CTXF_STS_TX_BYTES GENMASK(4, 0)
+#define NPCM_I2CTXF_STS_TX_THST BIT(6)
+
+// NPCM_I2CRXF_STS reg fields
+#define NPCM_I2CRXF_STS_RX_BYTES GENMASK(4, 0)
+#define NPCM_I2CRXF_STS_RX_THST BIT(6)
+
+// NPCM_I2CFIF_CTL reg fields
+#define NPCM_I2CFIF_CTL_FIFO_EN BIT(4)
+
+// NPCM_I2CRXF_CTL reg fields
+#define NPCM_I2CRXF_CTL_RX_THR GENMASK(4, 0)
+#define NPCM_I2CRXF_CTL_LAST_PEC BIT(5)
+#define NPCM_I2CRXF_CTL_THR_RXIE BIT(6)
+
+#define I2C_HW_FIFO_SIZE 16
+
+// I2C_VER reg fields
+#define I2C_VER_VERSION GENMASK(6, 0)
+#define I2C_VER_FIFO_EN BIT(7)
+
+// stall/stuck timeout
+const unsigned int DEFAULT_STALL_COUNT = 25;
+
+// retries in a loop for master abort
+const unsigned int RETRIES_NUM = 10000;
+
+// clk settings. values in KHZ.
+// The HW has different configuration modes per range
+// each range handled separetly
+const unsigned int I2C_FREQ_MIN = 10;
+const unsigned int I2C_FREQ_MAX = 1000;
+const unsigned int I2C_FREQ_100KHZ = 100;
+const unsigned int I2C_FREQ_400KHZ = 400;
+const unsigned int I2C_FREQ_1MHZ = 1000;
+
+// SCLFRQ min/max field values
+const unsigned int SCLFRQ_MIN = 10;
+const unsigned int SCLFRQ_MAX = 511;
+
+// SCLFRQ field position
+#define SCLFRQ_0_TO_6 GENMASK(6, 0)
+#define SCLFRQ_7_TO_8 GENMASK(8, 7)
+
+const unsigned int I2C_NUM_OF_ADDR = 10;
+
+#define NPCM_I2C_EVENT_START BIT(0)
+#define NPCM_I2C_EVENT_STOP BIT(1)
+#define NPCM_I2C_EVENT_ABORT BIT(2)
+#define NPCM_I2C_EVENT_WRITE BIT(3)
+
+#define NPCM_I2C_EVENT_READ BIT(4)
+#define NPCM_I2C_EVENT_BER BIT(5)
+#define NPCM_I2C_EVENT_NACK BIT(6)
+#define NPCM_I2C_EVENT_TO BIT(7)
+
+#define NPCM_I2C_EVENT_EOB BIT(8)
+#define NPCM_I2C_EVENT_STALL BIT(9)
+#define NPCM_I2C_EVENT_CB BIT(10)
+#define NPCM_I2C_EVENT_DONE BIT(11)
+
+#define NPCM_I2C_EVENT_READ1 BIT(12)
+#define NPCM_I2C_EVENT_READ2 BIT(13)
+#define NPCM_I2C_EVENT_READ3 BIT(14)
+#define NPCM_I2C_EVENT_READ4 BIT(15)
+
+#define NPCM_I2C_EVENT_NMATCH_SLV BIT(16)
+#define NPCM_I2C_EVENT_NMATCH_MSTR BIT(17)
+#define NPCM_I2C_EVENT_BER_SLV BIT(18)
+
+#define NPCM_I2C_EVENT_LOG(event) (bus->event_log |= event)
+
+// Status of one I2C module
+struct npcm_i2c {
+ struct i2c_adapter adap;
+ struct device *dev;
+ unsigned char __iomem *reg;
+ spinlock_t lock; /* IRQ synchronization */
+ struct completion cmd_complete;
+ int irq;
+ int cmd_err;
+ struct i2c_msg *msgs;
+ int msgs_num;
+ int num;
+ u32 apb_clk;
+ struct i2c_bus_recovery_info rinfo;
+ enum i2c_state state;
+ enum i2c_oper operation;
+ enum i2c_mode master_or_slave;
+ enum i2c_state_ind stop_ind;
+ u8 dest_addr;
+ u8 *rd_buf;
+ u16 rd_size;
+ u16 rd_ind;
+ u8 *wr_buf;
+ u16 wr_size;
+ u16 wr_ind;
+ bool fifo_use;
+
+ // PEC bit mask per slave address.
+ // 1: use PEC for this address,
+ // 0: do not use PEC for this address
+ u16 PEC_mask;
+ bool PEC_use;
+ bool read_block_use;
+ u8 int_cnt;
+ u32 event_log;
+ u32 event_log_prev;
+ u32 clk_period_us;
+ unsigned long int_time_stamp;
+ unsigned long bus_freq; // in kHz
+ u32 xmits;
+
+};
+
+static inline void npcm_i2c_select_bank(struct npcm_i2c *bus,
+ enum i2c_bank bank)
+{
+ if (bank == I2C_BANK_0)
+ iowrite8(ioread8(bus->reg + NPCM_I2CCTL3) & ~I2CCTL3_BNK_SEL,
+ bus->reg + NPCM_I2CCTL3);
+ else
+ iowrite8(ioread8(bus->reg + NPCM_I2CCTL3) | I2CCTL3_BNK_SEL,
+ bus->reg + NPCM_I2CCTL3);
+}
+
+static void npcm_i2c_init_params(struct npcm_i2c *bus)
+{
+ bus->stop_ind = I2C_NO_STATUS_IND;
+ bus->rd_size = 0;
+ bus->wr_size = 0;
+ bus->rd_ind = 0;
+ bus->wr_ind = 0;
+ bus->int_cnt = 0;
+ bus->event_log_prev = bus->event_log;
+ bus->event_log = 0;
+ bus->read_block_use = false;
+ bus->int_time_stamp = 0;
+ bus->PEC_use = false;
+ bus->PEC_mask = 0;
+ if (bus->slave)
+ bus->master_or_slave = I2C_SLAVE;
+}
+
+static inline void npcm_i2c_wr_byte(struct npcm_i2c *bus, u8 data)
+{
+ iowrite8(data, bus->reg + NPCM_I2CSDA);
+}
+
+static inline void npcm_i2c_rd_byte(struct npcm_i2c *bus, u8 *data)
+{
+ *data = ioread8(bus->reg + NPCM_I2CSDA);
+}
+
+static inline u16 npcm_i2c_get_index(struct npcm_i2c *bus)
+{
+ u16 index = 0;
+
+ if (bus->operation == I2C_READ_OPER)
+ index = bus->rd_ind;
+ else if (bus->operation == I2C_WRITE_OPER)
+ index = bus->wr_ind;
+
+ return index;
+}
+
+// quick protocol (just address):
+static inline bool npcm_i2c_is_quick(struct npcm_i2c *bus)
+{
+ if (bus->wr_size == 0 && bus->rd_size == 0)
+ return true;
+ return false;
+}
+
+static void npcm_i2c_disable(struct npcm_i2c *bus)
+{
+ int i;
+
+ // select bank 0 for I2C addresses
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+
+ // Slave addresses removal
+ for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OF_ADDR; i++)
+ iowrite8(0, bus->reg + npcm_i2caddr[i]);
+
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ // Disable module.
+ iowrite8(ioread8(bus->reg + NPCM_I2CCTL2) & ~I2CCTL2_ENABLE,
+ bus->reg + NPCM_I2CCTL2);
+
+ bus->state = I2C_DISABLE;
+}
+
+static void npcm_i2c_enable(struct npcm_i2c *bus)
+{
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL2) | I2CCTL2_ENABLE),
+ bus->reg + NPCM_I2CCTL2);
+
+ bus->state = I2C_IDLE;
+}
+
+static bool npcm_i2c_wait_for_bus_free(struct npcm_i2c *bus, bool may_sleep)
+{
+ int cnt = 0;
+ int max_count = 2; /* wait for 2 ms */
+
+ if (may_sleep)
+ might_sleep();
+ else
+ max_count = max_count * 100; /* since each delay is 10 us */
+
+ while (ioread8(bus->reg + NPCM_I2CCST) & NPCM_I2CCST_BUSY) {
+ if (cnt < max_count) {
+ if (may_sleep)
+ msleep_interruptible(1);
+ else
+ udelay(10);
+ cnt++;
+
+ } else {
+ bus->cmd_err = -EAGAIN;
+ return false;
+ }
+ }
+ return true;
+}
+
+// enable\disable end of busy (EOB) interrupt
+static inline void npcm_i2c_eob_int(struct npcm_i2c *bus, bool enable)
+{
+ // Clear EO_BUSY pending bit:
+ iowrite8(ioread8(bus->reg + NPCM_I2CCST3) | NPCM_I2CCST3_EO_BUSY,
+ bus->reg + NPCM_I2CCST3);
+
+ if (enable) {
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) |
+ NPCM_I2CCTL1_EOBINTE) & ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+ } else {
+ iowrite8(ioread8(bus->reg + NPCM_I2CCTL1) &
+ ~NPCM_I2CCTL1_EOBINTE & ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+ }
+}
+
+static inline bool npcm_i2c_tx_fifo_empty(struct npcm_i2c *bus)
+{
+ u8 tx_fifo_sts = ioread8(bus->reg + NPCM_I2CTXF_STS);
+
+ // check if TX FIFO is not empty
+ if ((tx_fifo_sts & NPCM_I2CTXF_STS_TX_BYTES) == 0)
+ return false;
+
+ // check if TX FIFO status bit is set:
+ return (bool)FIELD_GET(NPCM_I2CTXF_STS_TX_THST, tx_fifo_sts);
+}
+
+static inline bool npcm_i2c_rx_fifo_full(struct npcm_i2c *bus)
+{
+ u8 rx_fifo_sts = ioread8(bus->reg + NPCM_I2CRXF_STS);
+
+ // check if RX FIFO is not empty:
+ if ((rx_fifo_sts & NPCM_I2CRXF_STS_RX_BYTES) == 0)
+ return false;
+
+ // check if rx fifo full status is set:
+ return (bool)FIELD_GET(NPCM_I2CRXF_STS_RX_THST, rx_fifo_sts);
+}
+
+static inline void npcm_i2c_clear_fifo_int(struct npcm_i2c *bus)
+{
+ iowrite8((ioread8(bus->reg + NPCM_I2CFIF_CTS) &
+ NPCM_I2CFIF_CTS_SLVRSTR) |
+ NPCM_I2CFIF_CTS_RXF_TXE,
+ bus->reg + NPCM_I2CFIF_CTS);
+}
+
+static inline void npcm_i2c_clear_tx_fifo(struct npcm_i2c *bus)
+{
+ iowrite8(ioread8(bus->reg + NPCM_I2CTXF_STS) | NPCM_I2CTXF_STS_TX_THST,
+ bus->reg + NPCM_I2CTXF_STS);
+}
+
+static inline void npcm_i2c_clear_rx_fifo(struct npcm_i2c *bus)
+{
+ iowrite8(ioread8(bus->reg + NPCM_I2CRXF_STS) | NPCM_I2CRXF_STS_RX_THST,
+ bus->reg + NPCM_I2CRXF_STS);
+}
+
+static void npcm_i2c_int_enable(struct npcm_i2c *bus, bool enable)
+{
+ if (enable)
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) |
+ NPCM_I2CCTL1_INTEN) & ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+ else
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) &
+ ~NPCM_I2CCTL1_INTEN) & ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+}
+
+static inline void npcm_i2c_master_start(struct npcm_i2c *bus)
+{
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_START);
+
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) | NPCM_I2CCTL1_START) &
+ ~(NPCM_I2CCTL1_STOP | NPCM_I2CCTL1_ACK),
+ bus->reg + NPCM_I2CCTL1);
+}
+
+static inline void npcm_i2c_master_stop(struct npcm_i2c *bus)
+{
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_STOP);
+
+ // override HW issue: I2Cus may fail to supply stop condition in Master
+ // Write operation.
+ // Need to delay at least 5 us from the last int, before issueing a stop
+ udelay(10);
+
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) | NPCM_I2CCTL1_STOP) &
+ ~(NPCM_I2CCTL1_START | NPCM_I2CCTL1_ACK),
+ bus->reg + NPCM_I2CCTL1);
+
+ if (bus->fifo_use) {
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ if (bus->operation == I2C_READ_OPER)
+ npcm_i2c_clear_rx_fifo(bus);
+ else
+ npcm_i2c_clear_tx_fifo(bus);
+
+ npcm_i2c_clear_fifo_int(bus);
+
+ iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
+ }
+}
+
+static inline void npcm_i2c_stall_after_start(struct npcm_i2c *bus, bool stall)
+{
+ if (stall)
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) |
+ NPCM_I2CCTL1_STASTRE) & ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+ else
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) &
+ ~NPCM_I2CCTL1_STASTRE) & ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+}
+
+static inline void npcm_i2c_nack(struct npcm_i2c *bus)
+{
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) | NPCM_I2CCTL1_ACK) &
+ ~(NPCM_I2CCTL1_STOP | NPCM_I2CCTL1_START),
+ bus->reg + NPCM_I2CCTL1);
+}
+
+static int npcm_i2c_slave_enable_l(struct npcm_i2c *bus,
+ enum i2c_addr addr_type, u8 addr,
+ bool enable);
+
+static void npcm_i2c_reset(struct npcm_i2c *bus)
+{
+ // Save NPCM_I2CCTL1 relevant bits. It is being cleared when the
+ // module is disabled
+ u8 i2cctl1;
+
+ i2cctl1 = ioread8(bus->reg + NPCM_I2CCTL1);
+
+ // Disable the I2C module
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL2) & ~I2CCTL2_ENABLE),
+ bus->reg + NPCM_I2CCTL2);
+
+ // Enable the I2C module
+ npcm_i2c_enable(bus);
+
+ // Restore NPCM_I2CCTL1 status
+ iowrite8(i2cctl1 & ~NPCM_I2CCTL1_RWS_FIELDS, bus->reg + NPCM_I2CCTL1);
+
+ // Clear BB (BUS BUSY) bit
+ iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
+
+ iowrite8(0xFF, bus->reg + NPCM_I2CST);
+
+ // Clear EOB bit
+ iowrite8(NPCM_I2CCST3_EO_BUSY, bus->reg + NPCM_I2CCST3);
+
+ // Clear all fifo bits:
+ iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS);
+
+ bus->state = I2C_IDLE;
+}
+
+static inline bool npcm_i2c_is_master(struct npcm_i2c *bus)
+{
+ return (bool)FIELD_GET(NPCM_I2CST_MASTER,
+ ioread8(bus->reg + NPCM_I2CST));
+}
+
+static void npcm_i2c_callback(struct npcm_i2c *bus,
+ enum i2c_state_ind op_status, u16 info)
+{
+ struct i2c_msg *msgs = bus->msgs;
+ int msgs_num = bus->msgs_num;
+
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_CB);
+
+ if (!msgs)
+ return;
+
+ if (completion_done(&bus->cmd_complete) == true)
+ return;
+
+ switch (op_status) {
+ case I2C_MASTER_DONE_IND:
+ bus->cmd_err = bus->msgs_num;
+ // fall through:
+ case I2C_BLOCK_BYTES_ERR_IND:
+ // Master transaction finished and all transmit bytes were sent
+ if (bus->msgs) {
+ if (msgs[0].flags & I2C_M_RD)
+ msgs[0].len = info;
+ else if (msgs_num == 2 &&
+ msgs[1].flags & I2C_M_RD)
+ msgs[1].len = info;
+ }
+
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_DONE);
+
+ if (completion_done(&bus->cmd_complete) == false)
+ complete(&bus->cmd_complete);
+ break;
+
+ case I2C_NACK_IND:
+ // MASTER transmit got a NACK before tx all bytes
+ // info: number of transmitted bytes
+ bus->cmd_err = -ENXIO;
+ if (bus->master_or_slave == I2C_MASTER)
+ complete(&bus->cmd_complete);
+
+ break;
+ case I2C_BUS_ERR_IND:
+ // Bus error
+ bus->cmd_err = -EAGAIN;
+ if (bus->master_or_slave == I2C_MASTER)
+ complete(&bus->cmd_complete);
+
+ break;
+ case I2C_WAKE_UP_IND:
+ // I2Cus wake up
+ break;
+ default:
+ break;
+ }
+
+ bus->operation = I2C_NO_OPER;
+ if (bus->slave)
+ bus->master_or_slave = I2C_SLAVE;
+}
+
+static u32 npcm_i2c_get_fifo_fullness(struct npcm_i2c *bus)
+{
+ if (bus->operation == I2C_WRITE_OPER)
+ return FIELD_GET(NPCM_I2CTXF_STS_TX_BYTES,
+ ioread8(bus->reg + NPCM_I2CTXF_STS));
+ else if (bus->operation == I2C_READ_OPER)
+ return FIELD_GET(NPCM_I2CRXF_STS_RX_BYTES,
+ ioread8(bus->reg + NPCM_I2CRXF_STS));
+ return 0;
+}
+
+static void npcm_i2c_write_to_fifo_master(struct npcm_i2c *bus,
+ u16 max_bytes_to_send)
+{
+ // Fill the FIFO, while the FIFO is not full and there are more bytes to
+ // write
+ if (max_bytes_to_send == 0)
+ return;
+ while ((max_bytes_to_send--) && (I2C_HW_FIFO_SIZE -
+ npcm_i2c_get_fifo_fullness(bus))) {
+ if (bus->wr_ind < bus->wr_size)
+ npcm_i2c_wr_byte(bus, bus->wr_buf[bus->wr_ind++]);
+ else
+ npcm_i2c_wr_byte(bus, 0xFF);
+ }
+}
+
+// configure the FIFO before using it. If nread is -1 RX FIFO will not be
+// configured. same for nwrite
+static void npcm_i2c_set_fifo(struct npcm_i2c *bus, int nread, int nwrite)
+{
+ u8 rxf_ctl = 0;
+
+ if (!bus->fifo_use)
+ return;
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+ npcm_i2c_clear_tx_fifo(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+
+ // configure RX FIFO
+ if (nread > 0) {
+ rxf_ctl = min_t(u16, (u16)nread, (u16)I2C_HW_FIFO_SIZE);
+
+ // set LAST bit. if LAST is set enxt FIFO packet is nacked
+ // regular read of less then buffer size:
+ if (nread <= I2C_HW_FIFO_SIZE)
+ rxf_ctl |= NPCM_I2CRXF_CTL_LAST_PEC;
+ // if we are about to read the first byte in blk rd mode,
+ // don't NACK it. BTW, if slave return zero size HW can't NACK
+ // it immidiattly, it will read extra byte and then NACK.
+ if (bus->rd_ind == 0 && bus->read_block_use) {
+ // set fifo to read one byte, no last:
+ rxf_ctl = 1;
+ }
+
+ // set fifo size:
+ iowrite8(rxf_ctl, bus->reg + NPCM_I2CRXF_CTL);
+ }
+
+ // configure TX FIFO
+ if (nwrite > 0) {
+ if (nwrite > I2C_HW_FIFO_SIZE)
+ // data to send is more then FIFO size.
+ // Configure the FIFO int to be after of FIFO is cleared
+ iowrite8(I2C_HW_FIFO_SIZE, bus->reg + NPCM_I2CTXF_CTL);
+ else
+ iowrite8(nwrite, bus->reg + NPCM_I2CTXF_CTL);
+
+ npcm_i2c_clear_tx_fifo(bus);
+ }
+}
+
+static void npcm_i2c_read_from_fifo(struct npcm_i2c *bus, u8 bytes_in_fifo)
+{
+ u8 data;
+
+ while (bytes_in_fifo--) {
+ npcm_i2c_rd_byte(bus, &data);
+
+ if (bus->master_or_slave == I2C_MASTER) {
+ if (bus->rd_ind < bus->rd_size)
+ bus->rd_buf[bus->rd_ind++] = data;
+ } else { // I2C_SLAVE:
+ }
+ }
+}
+
+static int npcm_i2c_master_abort(struct npcm_i2c *bus)
+{
+ int ret = 0;
+
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_ABORT);
+
+ // Only current master is allowed to issue Stop Condition
+ if (npcm_i2c_is_master(bus)) {
+ npcm_i2c_eob_int(bus, true);
+ npcm_i2c_master_stop(bus);
+
+ // Clear NEGACK, STASTR and BER bits
+ iowrite8(NPCM_I2CST_BER | NPCM_I2CST_NEGACK | NPCM_I2CST_STASTR,
+ bus->reg + NPCM_I2CST);
+ }
+
+ return ret;
+}
+
+static void npcm_i2c_master_fifo_read(struct npcm_i2c *bus)
+{
+ int rcount;
+ int fifo_bytes;
+ enum i2c_state_ind ind = I2C_MASTER_DONE_IND;
+
+ fifo_bytes = npcm_i2c_get_fifo_fullness(bus);
+
+ rcount = bus->rd_size - bus->rd_ind;
+
+ // In order not to change the RX_TRH during transaction (we found that
+ // this might be problematic if it takes too much time to read the FIFO)
+ // we read the data in the following way. If the number of bytes to
+ // read == FIFO Size + C (where C < FIFO Size)then first read C bytes
+ // and in the next int we read rest of the data.
+ if (rcount < (2 * I2C_HW_FIFO_SIZE) && rcount > I2C_HW_FIFO_SIZE)
+ fifo_bytes = (u8)(rcount - I2C_HW_FIFO_SIZE);
+
+ if ((rcount - fifo_bytes) <= 0) {
+ // last bytes are about to be read - end of transaction.
+ // Stop should be set before reading last byte.
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ4);
+
+ bus->state = I2C_STOP_PENDING;
+ bus->stop_ind = ind;
+
+ npcm_i2c_eob_int(bus, true);
+ npcm_i2c_master_stop(bus);
+ npcm_i2c_read_from_fifo(bus, fifo_bytes);
+ } else {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ3);
+ npcm_i2c_read_from_fifo(bus, fifo_bytes);
+ rcount = bus->rd_size - bus->rd_ind;
+ npcm_i2c_set_fifo(bus, rcount, -1);
+ }
+}
+
+static void npcm_i2c_int_master_handler_write(struct npcm_i2c *bus)
+{
+ u16 wcount;
+
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_WRITE);
+ if (bus->fifo_use)
+ npcm_i2c_clear_tx_fifo(bus); // clear the TX fifo status bit
+
+ // Master write operation - last byte handling
+ if (bus->wr_ind == bus->wr_size) {
+ if (bus->fifo_use && npcm_i2c_get_fifo_fullness(bus) > 0)
+ // No more bytes to send (to add to the FIFO),
+ // however the FIFO is not empty yet. It is
+ // still in the middle of tx. Currently there's nothing
+ // to do except for waiting to the end of the tx.
+ // We will get an int when the FIFO will get empty.
+ return;
+
+ if (bus->rd_size == 0) {
+ // all bytes have been written, in a pure wr operation
+ npcm_i2c_eob_int(bus, true);
+
+ bus->state = I2C_STOP_PENDING;
+ bus->stop_ind = I2C_MASTER_DONE_IND;
+
+ npcm_i2c_master_stop(bus);
+ // Clear SDA Status bit (by writing dummy byte)
+ npcm_i2c_wr_byte(bus, 0xFF);
+
+ } else {
+ // last write-byte written on previous int - need to
+ // restart & send slave address
+ npcm_i2c_set_fifo(bus, bus->rd_size, -1);
+
+ // Generate repeated start upon next write to SDA
+ npcm_i2c_master_start(bus);
+
+ if (bus->rd_size == 1)
+ // Receiving one byte only - stall after
+ // successful completion of send
+ // address byte. If we NACK here,
+ // and slave doesn't ACK the address, we
+ // might unintentionally NACK the next
+ // multi-byte read
+ npcm_i2c_stall_after_start(bus, true);
+
+ // Next int will occur on read
+ bus->operation = I2C_READ_OPER;
+
+ // send the slave address in read direction
+ npcm_i2c_wr_byte(bus, bus->dest_addr | 0x1);
+ }
+ } else {
+ // write next byte not last byte and not slave address
+ if (!bus->fifo_use || bus->wr_size == 1) {
+ npcm_i2c_wr_byte(bus, bus->wr_buf[bus->wr_ind++]);
+ } else {
+ wcount = bus->wr_size - bus->wr_ind;
+ npcm_i2c_set_fifo(bus, -1, wcount);
+ npcm_i2c_write_to_fifo_master(bus, wcount);
+ }
+ }
+}
+
+static void npcm_i2c_int_master_handler_read(struct npcm_i2c *bus)
+{
+ u16 block_extra_bytes_size;
+ u8 data;
+
+ // Master read operation (pure read or following a write operation).
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ);
+
+ // added bytes to the packet:
+ block_extra_bytes_size = (u8)bus->read_block_use + (u8)bus->PEC_use;
+
+ // Perform master read, distinguishing between last byte and the rest of
+ // the bytes. The last byte should be read when the clock is stopped
+ if (bus->rd_ind == 0) { //first byte handling:
+ // in block protocol first byte is the size
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ1);
+ if (bus->read_block_use) {
+ // first byte in block protocol is the size:
+ npcm_i2c_rd_byte(bus, &data);
+
+ // if slave returned illegal size. read up to 32 bytes.
+ if (data >= I2C_SMBUS_BLOCK_MAX)
+ data = I2C_SMBUS_BLOCK_MAX;
+
+ // is data is 0 -> not supported. read at least one byte
+ if (data == 0)
+ data = 1;
+
+ bus->rd_size = data + block_extra_bytes_size;
+
+ bus->rd_buf[bus->rd_ind++] = data;
+
+ // clear RX FIFO interrupt status:
+ if (bus->fifo_use) {
+ iowrite8(NPCM_I2CFIF_CTS_RXF_TXE |
+ ioread8(bus->reg + NPCM_I2CFIF_CTS),
+ bus->reg + NPCM_I2CFIF_CTS);
+ }
+
+ npcm_i2c_set_fifo(bus, (bus->rd_size - 1), -1);
+ npcm_i2c_stall_after_start(bus, false);
+ } else {
+ npcm_i2c_clear_tx_fifo(bus);
+ npcm_i2c_master_fifo_read(bus);
+ }
+ } else {
+ if (bus->rd_size == block_extra_bytes_size &&
+ bus->read_block_use) {
+ bus->state = I2C_STOP_PENDING;
+ bus->stop_ind = I2C_BLOCK_BYTES_ERR_IND;
+ bus->cmd_err = -EIO;
+ npcm_i2c_eob_int(bus, true);
+ npcm_i2c_master_stop(bus);
+ npcm_i2c_read_from_fifo(bus,
+ npcm_i2c_get_fifo_fullness(bus)
+ );
+ } else {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ2);
+ npcm_i2c_master_fifo_read(bus);
+ }
+ }
+}
+
+static irqreturn_t npcm_i2c_int_master_handler(struct npcm_i2c *bus)
+{
+ irqreturn_t ret = IRQ_NONE;
+ u8 fif_cts;
+
+ if (FIELD_GET(NPCM_I2CST_NMATCH, ioread8(bus->reg + NPCM_I2CST))) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NMATCH_MSTR);
+ iowrite8(NPCM_I2CST_NMATCH, bus->reg + NPCM_I2CST);
+ npcm_i2c_nack(bus);
+ bus->stop_ind = I2C_BUS_ERR_IND;
+ npcm_i2c_callback(bus, bus->stop_ind, npcm_i2c_get_index(bus));
+
+ return IRQ_HANDLED;
+ }
+ // A NACK has occurred
+ if (FIELD_GET(NPCM_I2CST_NEGACK, ioread8(bus->reg + NPCM_I2CST))) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NACK);
+ if (bus->fifo_use) {
+ // if there are still untransmitted bytes in TX FIFO
+ // reduce them from wr_ind
+ if (bus->operation == I2C_WRITE_OPER)
+ bus->wr_ind -= npcm_i2c_get_fifo_fullness(bus);
+
+ // clear the FIFO
+ iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_I2CFIF_CTS);
+ }
+
+ // In master write operation, NACK is a problem
+ // number of bytes sent to master less than required
+ bus->stop_ind = I2C_NACK_IND;
+ // Only current master is allowed to issue Stop Condition
+ if (npcm_i2c_is_master(bus)) {
+ // stopping in the middle, not waiting for ints anymore
+ npcm_i2c_eob_int(bus, false);
+
+ npcm_i2c_master_stop(bus);
+
+ // Clear NEGACK, STASTR and BER bits
+ // In Master mode, NEGACK should be cleared only after
+ // generating STOP.
+ // In such case, the bus is released from stall only
+ // after the software clears NEGACK bit.
+ // Then a Stop condition is sent.
+ iowrite8(NPCM_I2CST_BER | NPCM_I2CST_NEGACK |
+ NPCM_I2CST_STASTR, bus->reg + NPCM_I2CST);
+
+ npcm_i2c_wait_for_bus_free(bus, false);
+ }
+ bus->state = I2C_IDLE;
+
+ // In Master mode, NACK should be cleared only after
+ // generating STOP.
+ // In such case, the bus is released from stall only after the
+ // software clears NACK bit.
+ // Then a Stop condition is sent.
+ npcm_i2c_callback(bus, bus->stop_ind, bus->wr_ind);
+ return IRQ_HANDLED;
+ }
+
+ // Master mode: a Bus Error has been identified
+ if (FIELD_GET(NPCM_I2CST_BER, ioread8(bus->reg + NPCM_I2CST))) {
+ // Check whether bus arbitration or Start or Stop during data
+ // xfer bus arbitration problem should not result in recovery
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_BER);
+ bus->stop_ind = I2C_BUS_ERR_IND;
+ if (npcm_i2c_is_master(bus)) {
+ npcm_i2c_master_abort(bus);
+ } else {
+ // Clear NEGACK, STASTR and BER bits
+ iowrite8(NPCM_I2CST_BER | NPCM_I2CST_NEGACK |
+ NPCM_I2CST_STASTR, bus->reg + NPCM_I2CST);
+
+ // Clear BB (BUS BUSY) bit
+ iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
+
+ bus->cmd_err = -EAGAIN;
+ npcm_i2c_callback(bus, bus->stop_ind,
+ npcm_i2c_get_index(bus));
+ }
+ bus->state = I2C_IDLE;
+ ret = IRQ_HANDLED;
+ return ret;
+ }
+
+ // A Master End of Busy (meaning Stop Condition happened)
+ // End of Busy int is on and End of Busy is set
+ if ((FIELD_GET(NPCM_I2CCTL1_EOBINTE,
+ ioread8(bus->reg + NPCM_I2CCTL1)) == 1) &&
+ (FIELD_GET(NPCM_I2CCST3_EO_BUSY,
+ ioread8(bus->reg + NPCM_I2CCST3)))) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_EOB);
+ npcm_i2c_eob_int(bus, false);
+ bus->state = I2C_IDLE;
+ npcm_i2c_callback(bus, bus->stop_ind, bus->rd_ind);
+ return IRQ_HANDLED;
+ }
+
+ // Address sent and requested stall occurred (Master mode)
+ if (FIELD_GET(NPCM_I2CST_STASTR, ioread8(bus->reg + NPCM_I2CST))) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_STALL);
+
+ if (npcm_i2c_is_quick(bus)) {
+ bus->state = I2C_STOP_PENDING;
+ bus->stop_ind = I2C_MASTER_DONE_IND;
+ npcm_i2c_eob_int(bus, true);
+ npcm_i2c_master_stop(bus);
+
+ } else if ((bus->rd_size == 1) && !bus->read_block_use) {
+ // Receiving one byte only - set NACK after ensuring
+ // slave ACKed the address byte
+ npcm_i2c_nack(bus);
+ }
+
+ // Reset stall-after-address-byte
+ npcm_i2c_stall_after_start(bus, false);
+
+ // Clear stall only after setting STOP
+ iowrite8(NPCM_I2CST_STASTR, bus->reg + NPCM_I2CST);
+
+ ret = IRQ_HANDLED;
+ }
+
+ // SDA status is set - TX or RX, master
+ if (FIELD_GET(NPCM_I2CST_SDAST, ioread8(bus->reg + NPCM_I2CST)) ||
+ (bus->fifo_use &&
+ (npcm_i2c_tx_fifo_empty(bus) || npcm_i2c_rx_fifo_full(bus)))) {
+ // Status Bit is cleared by writing to or reading from SDA
+ // (depending on current direction)
+
+ // Send address:
+ if (bus->state == I2C_IDLE) {
+ if (npcm_i2c_is_master(bus)) {
+ bus->stop_ind = I2C_WAKE_UP_IND;
+
+ // test stall on start
+ if (npcm_i2c_is_quick(bus) ||
+ bus->read_block_use)
+ // Need to stall after successful
+ // completion of sending address byte
+ npcm_i2c_stall_after_start(bus, true);
+ else
+ npcm_i2c_stall_after_start(bus, false);
+
+ // Receiving one byte only - stall after
+ // successful completion of sending address byte
+ // If we NACK here, and slave doesn't ACK the
+ // address, we might unintentionally NACK
+ // the next multi-byte read
+ if (bus->wr_size == 0 && bus->rd_size == 1)
+ npcm_i2c_stall_after_start(bus, true);
+
+ // Initiate I2Cus master transaction
+ // Generate a Start condition on the I2Cus
+
+ // select bank 1 for FIFO regs
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ fif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS);
+
+ // clear FIFO and relevant status bits.
+ iowrite8((fif_cts & ~NPCM_I2CFIF_CTS_SLVRSTR)
+ | NPCM_I2CFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_I2CFIF_CTS);
+
+ // and enable it
+ iowrite8((fif_cts & ~NPCM_I2CFIF_CTS_SLVRSTR)
+ | NPCM_I2CFIF_CTS_RXF_TXE,
+ bus->reg + NPCM_I2CFIF_CTS);
+
+ // Configure the FIFO threshold
+ // according to the needed # of bytes to read.
+ // Note: due to HW limitation can't config the
+ // rx fifo before
+ // got and ACK on the restart. LAST bit will not
+ // be reset unless RX completed.
+ // It will stay set on the next tx.
+ if (bus->wr_size)
+ npcm_i2c_set_fifo(bus, -1,
+ bus->wr_size);
+ else
+ npcm_i2c_set_fifo(bus, bus->rd_size,
+ -1);
+
+ bus->state = I2C_OPER_STARTED;
+
+ if (npcm_i2c_is_quick(bus) || bus->wr_size)
+ npcm_i2c_wr_byte(bus, bus->dest_addr);
+ else
+ npcm_i2c_wr_byte(bus, bus->dest_addr |
+ 0x01);
+ }
+
+ return IRQ_HANDLED;
+ // SDA status is set - transmit or receive: Handle master mode
+ } else {
+ if ((NPCM_I2CST_XMIT &
+ ioread8(bus->reg + NPCM_I2CST)) == 0) {
+ bus->operation = I2C_READ_OPER;
+ npcm_i2c_int_master_handler_read(bus);
+ } else {
+ bus->operation = I2C_WRITE_OPER;
+ npcm_i2c_int_master_handler_write(bus);
+ }
+ }
+ ret = IRQ_HANDLED;
+ }
+
+ return ret;
+}
+
+static int npcm_i2c_get_SCL(struct i2c_adapter *_adap)
+{
+ unsigned int ret = 0;
+ struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
+ u32 offset = 0;
+
+ offset = 0;
+ ret = FIELD_GET(I2CCTL3_SCL_LVL, ioread32(bus->reg + NPCM_I2CCTL3));
+
+ pr_debug("i2c%d get SCL 0x%08X\n", bus->num, ret);
+
+ return (ret >> (offset)) & 0x01;
+}
+
+static int npcm_i2c_get_SDA(struct i2c_adapter *_adap)
+{
+ unsigned int ret = 0;
+ struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
+ u32 offset = 0;
+
+ offset = 0;
+ ret = FIELD_GET(I2CCTL3_SDA_LVL, ioread32(bus->reg + NPCM_I2CCTL3));
+
+ pr_debug("i2c%d get SDA 0x%08X\n", bus->num, ret);
+
+ return (ret >> (offset)) & 0x01;
+}
+
+// recovery using TGCLK functionality of the module
+static int npcm_i2c_recovery_tgclk(struct i2c_adapter *_adap)
+{
+ int iter = 27; // Allow 3 bytes to be sent by the Slave
+ int retries = 0;
+ bool done = false;
+ int status = -(ENOTRECOVERABLE);
+ u8 fif_cts;
+ struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
+
+ if ((npcm_i2c_get_SDA(_adap) == 1) && (npcm_i2c_get_SCL(_adap) == 1)) {
+ dev_dbg(bus->dev, "TGCLK recovery bus%d: skipped bus not stuck",
+ bus->num);
+ npcm_i2c_reset(bus);
+ return status;
+ }
+
+ // Disable int
+ npcm_i2c_int_enable(bus, false);
+
+ npcm_i2c_disable(bus);
+ npcm_i2c_enable(bus);
+ iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
+ npcm_i2c_clear_tx_fifo(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+ iowrite8(0, bus->reg + NPCM_I2CRXF_CTL);
+ iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
+ npcm_i2c_stall_after_start(bus, false);
+
+ // select bank 1 for FIFO regs
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ fif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS);
+
+ // clear FIFO and relevant status bits.
+ iowrite8((fif_cts & ~NPCM_I2CFIF_CTS_SLVRSTR) |
+ NPCM_I2CFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_I2CFIF_CTS);
+
+ npcm_i2c_set_fifo(bus, -1, 0);
+
+ // Check If the SDA line is active (low)
+ if (npcm_i2c_get_SDA(_adap) == 0) {
+ // Repeat the following sequence until SDA is released
+ do {
+ // Issue a single SCL cycle
+ iowrite8(NPCM_I2CCST_TGSCL, bus->reg + NPCM_I2CCST);
+ retries = 10;
+ while (retries != 0 &&
+ FIELD_GET(NPCM_I2CCST_TGSCL,
+ ioread8(bus->reg + NPCM_I2CCST))) {
+ udelay(20);
+ retries--;
+ }
+
+ // tgclk failed to toggle
+ if (retries == 0)
+ dev_err(bus->dev, "recovery toggle timeout");
+ // If SDA line is inactive (high), stop
+ if (npcm_i2c_get_SDA(_adap))
+ done = true;
+ } while ((!done) && (--iter != 0));
+
+ // If SDA line is released: send start-addr-stop, to re-sync.
+ if (done) {
+ npcm_i2c_master_start(bus);
+
+ // Wait until START condition is sent, or RETRIES_NUM
+ retries = RETRIES_NUM;
+ while (retries && !npcm_i2c_is_master(bus)) {
+ udelay(20);
+ retries--;
+ }
+
+ // If START condition was sent
+ if (retries > 0) {
+ // Send an address byte in write direction:
+ npcm_i2c_wr_byte(bus, bus->dest_addr);
+ udelay(200);
+ npcm_i2c_master_stop(bus);
+ udelay(200);
+ status = 0;
+ }
+ }
+ }
+
+ // if bus is still stuck: total reset: set SCL low for 35ms:
+ if (unlikely(npcm_i2c_get_SDA(_adap) == 0)) {
+ // Generate a START, to synchronize Master and Slave
+ npcm_i2c_master_start(bus);
+
+ // Wait until START condition is sent, or RETRIES_NUM
+ retries = RETRIES_NUM;
+ while (retries && !npcm_i2c_is_master(bus))
+ retries--;
+
+ // set SCL low for a long time (note: this is unlikely)
+ usleep_range(25000, 35000);
+ npcm_i2c_master_stop(bus);
+ udelay(200);
+ status = 0;
+ }
+
+ dev_dbg(bus->dev, "recovery done, iter = %d, done = %d, retries = %d\n",
+ 27 - iter, done, retries);
+ // Enable I2C int and New Address Match int source
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) | NPCM_I2CCTL1_NMINTE) &
+ ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+ npcm_i2c_reset(bus);
+ npcm_i2c_int_enable(bus, true);
+ return status;
+}
+
+// recovery using bit banging functionality of the module
+static int npcm_i2c_recovery_init(struct i2c_adapter *_adap)
+{
+ struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
+ struct i2c_bus_recovery_info *rinfo = &bus->rinfo;
+
+ rinfo->recover_bus = npcm_i2c_recovery_tgclk;
+ rinfo->prepare_recovery = NULL;
+ rinfo->unprepare_recovery = NULL;
+ rinfo->set_scl = NULL;
+ rinfo->set_sda = NULL;
+
+ dev_dbg(bus->dev, "init i2c recovery using TGCLK\n");
+
+ rinfo->get_scl = npcm_i2c_get_SCL;
+ rinfo->get_sda = npcm_i2c_get_SDA;
+
+ _adap->bus_recovery_info = rinfo;
+
+ return 0;
+}
+
+static bool npcm_i2c_init_clk(struct npcm_i2c *bus, u32 bus_freq)
+{
+ u32 k1 = 0;
+ u32 k2 = 0;
+ u8 dbnct = 0;
+ u32 sclfrq = 0;
+ u8 hldt = 7;
+ bool fast_mode = false;
+ u32 src_clk_freq; // in KHz
+
+ src_clk_freq = bus->apb_clk / 1000;
+ bus->bus_freq = bus_freq;
+
+ if (bus_freq <= I2C_FREQ_100KHZ) {
+ sclfrq = src_clk_freq / (bus_freq * 4);
+
+ if (sclfrq < SCLFRQ_MIN || sclfrq > SCLFRQ_MAX)
+ return false;
+
+ if (src_clk_freq >= 40000)
+ hldt = 17;
+ else if (src_clk_freq >= 12500)
+ hldt = 15;
+ else
+ hldt = 7;
+ }
+
+ else if (bus_freq == I2C_FREQ_400KHZ) {
+ sclfrq = 0;
+ fast_mode = true;
+
+ if (src_clk_freq < 7500)
+ // 400KHZ cannot be supported for core clock < 7.5 MHZ
+ return false;
+
+ else if (src_clk_freq >= 50000) {
+ k1 = 80;
+ k2 = 48;
+ hldt = 12;
+ dbnct = 7;
+ }
+
+ // Master or Slave with frequency > 25 MHZ
+ else if (src_clk_freq > 25000) {
+ hldt = (u8)__KERNEL_DIV_ROUND_UP(src_clk_freq * 300,
+ 1000000) + 7;
+
+ k1 = __KERNEL_DIV_ROUND_UP(src_clk_freq * 1600,
+ 1000000);
+ k2 = __KERNEL_DIV_ROUND_UP(src_clk_freq * 900,
+ 1000000);
+ k1 = round_up(k1, 2);
+ k2 = round_up(k2 + 1, 2);
+ if (k1 < SCLFRQ_MIN || k1 > SCLFRQ_MAX ||
+ k2 < SCLFRQ_MIN || k2 > SCLFRQ_MAX)
+ return false;
+ }
+ }
+
+ else if (bus_freq == I2C_FREQ_1MHZ) {
+ sclfrq = 0;
+ fast_mode = true;
+
+ if (src_clk_freq < 24000)
+ // 1MHZ cannot be supported for master core clock < 15 MHZ
+ // or slave core clock < 24 MHZ
+ return false;
+
+ k1 = round_up((__KERNEL_DIV_ROUND_UP(src_clk_freq * 620,
+ 1000000)), 2);
+ k2 = round_up((__KERNEL_DIV_ROUND_UP(src_clk_freq * 380,
+ 1000000) + 1), 2);
+ if (k1 < SCLFRQ_MIN || k1 > SCLFRQ_MAX ||
+ k2 < SCLFRQ_MIN || k2 > SCLFRQ_MAX)
+ return false;
+
+ // Master or Slave with frequency > 40 MHZ
+ if (src_clk_freq > 40000) {
+ // Set HLDT:
+ // SDA hold time: (HLDT-7) * T(CLK) >= 120
+ // HLDT = 120/T(CLK) + 7 = 120 * FREQ(CLK) + 7
+ hldt = (u8)__KERNEL_DIV_ROUND_UP(src_clk_freq * 120,
+ 1000000) + 7;
+ } else {
+ hldt = 7;
+ dbnct = 2;
+ }
+ }
+
+ // Frequency larger than 1 MHZ
+ else
+ return false;
+
+ // After clock parameters calculation update reg (ENABLE should be 0):
+ iowrite8(FIELD_PREP(I2CCTL2_SCLFRQ6_0, sclfrq & 0x7F),
+ bus->reg + NPCM_I2CCTL2);
+
+ // force to bank 0, set SCL and fast mode
+ iowrite8(FIELD_PREP(I2CCTL3_400K_MODE, fast_mode) |
+ FIELD_PREP(I2CCTL3_SCLFRQ8_7, (sclfrq >> 7) & 0x3),
+ bus->reg + NPCM_I2CCTL3);
+
+ // Select Bank 0 to access NPCM_I2CCTL4/NPCM_I2CCTL5
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+
+ if (bus_freq >= I2C_FREQ_400KHZ) {
+ // Set SCL Low/High Time:
+ // k1 = 2 * SCLLT7-0 -> Low Time = k1 / 2
+ // k2 = 2 * SCLLT7-0 -> High Time = k2 / 2
+ iowrite8((u8)k1 / 2, bus->reg + NPCM_I2CSCLLT);
+ iowrite8((u8)k2 / 2, bus->reg + NPCM_I2CSCLHT);
+
+ iowrite8(dbnct, bus->reg + NPCM_I2CCTL5);
+ }
+
+ iowrite8(hldt, bus->reg + NPCM_I2CCTL4);
+
+ // Return to Bank 1, and stay there by default:
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ return true;
+}
+
+static bool npcm_i2c_init_module(struct npcm_i2c *bus, enum i2c_mode mode,
+ u32 bus_freq)
+{
+ // Check whether module already enabled or frequency is out of bounds
+ if ((bus->state != I2C_DISABLE && bus->state != I2C_IDLE) ||
+ bus_freq < I2C_FREQ_MIN || bus_freq > I2C_FREQ_MAX)
+ return false;
+
+ npcm_i2c_disable(bus);
+
+ // Configure FIFO mode :
+ if (FIELD_GET(I2C_VER_FIFO_EN, ioread8(bus->reg + I2C_VER))) {
+ bus->fifo_use = true;
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+ iowrite8(ioread8(bus->reg + NPCM_I2CFIF_CTL) |
+ NPCM_I2CFIF_CTL_FIFO_EN, bus->reg + NPCM_I2CFIF_CTL);
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+ } else {
+ bus->fifo_use = false;
+ }
+
+ // Configure I2C module clock frequency
+ if (!npcm_i2c_init_clk(bus, bus_freq)) {
+ dev_err(bus->dev, "npcm_i2c_init_clk failed\n");
+ return false;
+ }
+
+ // Enable module (before configuring CTL1)
+ npcm_i2c_enable(bus);
+ bus->state = I2C_IDLE;
+
+ // Enable I2C int and New Address Match int source
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) | NPCM_I2CCTL1_NMINTE) &
+ ~NPCM_I2CCTL1_RWS_FIELDS,
+ bus->reg + NPCM_I2CCTL1);
+
+ npcm_i2c_int_enable(bus, true);
+
+ npcm_i2c_reset(bus);
+
+ return true;
+}
+
+static int __npcm_i2c_init(struct npcm_i2c *bus, struct platform_device *pdev)
+{
+ u32 clk_freq;
+ int ret;
+
+ // Initialize the internal data structures
+ bus->state = I2C_DISABLE;
+ bus->master_or_slave = I2C_SLAVE;
+ bus->int_time_stamp = 0;
+ bus->slave = NULL;
+ bus->xmits = 0;
+
+ ret = of_property_read_u32(pdev->dev.of_node,
+ "bus-frequency", &clk_freq);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Could not read bus-frequency property\n");
+ clk_freq = 100000;
+ }
+
+ ret = npcm_i2c_init_module(bus, I2C_MASTER, clk_freq / 1000);
+ if (!ret) {
+ dev_err(&pdev->dev, "npcm_i2c_init_module() failed\n");
+ return -1;
+ }
+
+ return 0;
+}
+
+static irqreturn_t npcm_i2c_bus_irq(int irq, void *dev_id)
+{
+ irqreturn_t ret;
+ struct npcm_i2c *bus = dev_id;
+
+ bus->int_cnt++;
+
+ if (npcm_i2c_is_master(bus))
+ bus->master_or_slave = I2C_MASTER;
+
+ if (bus->master_or_slave == I2C_MASTER) {
+ bus->int_time_stamp = jiffies;
+ ret = npcm_i2c_int_master_handler(bus);
+ if (ret == IRQ_HANDLED)
+ return ret;
+ }
+ return IRQ_HANDLED;
+}
+
+static bool npcm_i2c_master_start_xmit(struct npcm_i2c *bus,
+ u8 slave_addr, u16 nwrite, u16 nread,
+ u8 *write_data, u8 *read_data,
+ bool use_PEC, bool use_read_block)
+{
+ if (bus->state != I2C_IDLE) {
+ bus->cmd_err = -(EBUSY);
+ return false;
+ }
+
+ bus->xmits++;
+
+ bus->dest_addr = (u8)(slave_addr << 1);// Translate 7bit to 8bit format
+ bus->wr_buf = write_data;
+ bus->wr_size = nwrite;
+ bus->wr_ind = 0;
+ bus->rd_buf = read_data;
+ bus->rd_size = nread;
+ bus->rd_ind = 0;
+ bus->PEC_use = 0;
+
+ // for write, PEC is appended to buffer from i2c IF. PEC flag is ignored
+ if (nread)
+ bus->PEC_use = use_PEC;
+ bus->read_block_use = use_read_block;
+ if (nread && !nwrite)
+ bus->operation = I2C_READ_OPER;
+ else
+ bus->operation = I2C_WRITE_OPER;
+
+ bus->int_cnt = 0;
+ bus->event_log = 0;
+
+ if (bus->fifo_use) {
+ u8 i2cfif_cts;
+ // select bank 1 for FIFO regs
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ i2cfif_cts = ioread8(bus->reg + NPCM_I2CFIF_CTS);
+
+ // clear FIFO and relevant status bits.
+ iowrite8((i2cfif_cts & (~NPCM_I2CFIF_CTS_SLVRSTR)) |
+ NPCM_I2CFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_I2CFIF_CTS);
+ }
+
+ bus->state = I2C_IDLE;
+
+ npcm_i2c_stall_after_start(bus, true);
+ npcm_i2c_master_start(bus);
+
+ return true;
+}
+
+static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ struct npcm_i2c *bus = container_of(adap, struct npcm_i2c, adap);
+ struct i2c_msg *msg0, *msg1;
+ unsigned long time_left, flags;
+ u16 nwrite, nread;
+ u8 *write_data, *read_data;
+ u8 slave_addr;
+ int timeout;
+ int ret = 0;
+ bool read_block = false;
+ bool read_PEC = false;
+ u8 bus_busy;
+ unsigned long timeout_usec;
+
+ if (unlikely(bus->state == I2C_DISABLE)) {
+ dev_err(bus->dev, "I2C%d module is disabled", bus->num);
+ return -EINVAL;
+ }
+
+ if (num > 2 || num < 1) {
+ dev_err(bus->dev, "I2C cmd not supported num of msgs=%d", num);
+ return -EINVAL;
+ }
+
+ msg0 = &msgs[0];
+ slave_addr = msg0->addr;
+ if (msg0->flags & I2C_M_RD) { // read
+ if (num == 2) {
+ dev_err(bus->dev, "num=2 but 1st msg rd instead of wr");
+ return -EINVAL;
+ }
+ nwrite = 0;
+ write_data = NULL;
+ read_data = msg0->buf;
+ if (msg0->flags & I2C_M_RECV_LEN) {
+ nread = 1;
+ read_block = true;
+ if (msg0->flags & I2C_CLIENT_PEC)
+ read_PEC = true;
+ } else {
+ nread = msg0->len;
+ }
+ } else { // write
+ nwrite = msg0->len;
+ write_data = msg0->buf;
+ nread = 0;
+ read_data = NULL;
+ if (num == 2) {
+ msg1 = &msgs[1];
+ read_data = msg1->buf;
+ if (slave_addr != msg1->addr) {
+ dev_err(bus->dev,
+ "SA==%02x but msg1->addr==%02x\n",
+ slave_addr, msg1->addr);
+ return -EINVAL;
+ }
+ if ((msg1->flags & I2C_M_RD) == 0) {
+ dev_err(bus->dev,
+ "num = 2 but both msg are write.\n");
+ return -EINVAL;
+ }
+ if (msg1->flags & I2C_M_RECV_LEN) {
+ nread = 1;
+ read_block = true;
+ if (msg1->flags & I2C_CLIENT_PEC)
+ read_PEC = true;
+ } else {
+ nread = msg1->len;
+ read_block = false;
+ }
+ }
+ }
+
+ /* Adaptive TimeOut: astimated time in usec + 100% margin */
+ timeout_usec = (2 * 10000 / bus->bus_freq) * (2 + nread + nwrite);
+ timeout = max(msecs_to_jiffies(35), usecs_to_jiffies(timeout_usec));
+ if (nwrite >= 32 * 1024 || nread >= 32 * 1024) {
+ dev_err(bus->dev, "i2c%d buffer too big\n", bus->num);
+ return -EINVAL;
+ }
+
+ time_left = jiffies +
+ msecs_to_jiffies(DEFAULT_STALL_COUNT) + 1;
+ do {
+ /* we must clear slave address immediately when the bus is not
+ * busy, so we spinlock it, but we don't keep the lock for the
+ * entire while since it is too long.
+ */
+ spin_lock_irqsave(&bus->lock, flags);
+ bus_busy = ioread8(bus->reg + NPCM_I2CCST) & NPCM_I2CCST_BB;
+ if (!bus_busy && bus->slave)
+ iowrite8((bus->slave->addr & 0x7F),
+ bus->reg + NPCM_I2CADDR1);
+ spin_unlock_irqrestore(&bus->lock, flags);
+
+ if (!bus_busy)
+ break;
+ } while (time_is_after_jiffies(time_left));
+
+ if (bus_busy) {
+ iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
+ npcm_i2c_reset(bus);
+ i2c_recover_bus(adap);
+ return -EAGAIN;
+ }
+
+ npcm_i2c_init_params(bus);
+ bus->dest_addr = slave_addr;
+ bus->msgs = msgs;
+ bus->msgs_num = num;
+ bus->read_block_use = read_block;
+
+ reinit_completion(&bus->cmd_complete);
+
+ if (!npcm_i2c_master_start_xmit(bus, slave_addr, nwrite, nread,
+ write_data, read_data, read_PEC,
+ read_block))
+ ret = -(EBUSY);
+
+ if (ret != -(EBUSY)) {
+ time_left = wait_for_completion_timeout(&bus->cmd_complete,
+ timeout);
+
+ if (time_left == 0) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_TO);
+ if (bus->master_or_slave == I2C_MASTER) {
+ dev_dbg(bus->dev,
+ "i2c%d TO = %d\n", bus->num, timeout);
+ i2c_recover_bus(adap);
+ bus->cmd_err = -EIO;
+ bus->state = I2C_IDLE;
+ }
+ }
+ }
+ ret = bus->cmd_err;
+
+ // if there was BER, check if need to recover the bus:
+ if (bus->cmd_err == -EAGAIN)
+ i2c_recover_bus(adap);
+
+ // If nothing went wrong, return number of messages x-ferred.
+ if (ret >= 0)
+ return num;
+
+ return ret;
+}
+
+static u32 npcm_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C |
+ I2C_FUNC_SMBUS_EMUL |
+ I2C_FUNC_SMBUS_BLOCK_DATA |
+ I2C_FUNC_SMBUS_PEC
+ ;
+}
+
+static const struct i2c_adapter_quirks npcm_i2c_quirks = {
+ .max_read_len = 32768,
+ .max_write_len = 32768,
+ .max_num_msgs = 2,
+ .flags = I2C_AQ_COMB_WRITE_THEN_READ
+};
+
+static const struct i2c_algorithm npcm_i2c_algo = {
+ .master_xfer = npcm_i2c_master_xfer,
+ .functionality = npcm_i2c_functionality,
+};
+
+static int npcm_i2c_probe_bus(struct platform_device *pdev)
+{
+ struct npcm_i2c *bus;
+ struct i2c_adapter *adap;
+ struct resource *res;
+ struct clk *i2c_clk;
+ static struct regmap *gcr_regmap;
+ static struct regmap *clk_regmap;
+ int ret;
+ int num;
+
+ bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
+ if (!bus)
+ return -ENOMEM;
+
+ bus->dev = &pdev->dev;
+
+#ifdef CONFIG_OF
+ num = of_alias_get_id(pdev->dev.of_node, "i2c");
+ bus->num = num;
+ i2c_clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(i2c_clk)) {
+ dev_err(bus->dev, " I2C probe failed: can't read clk\n");
+ return -EPROBE_DEFER;
+ }
+ bus->apb_clk = clk_get_rate(i2c_clk);
+ dev_dbg(bus->dev, "I2C APB clock is %d\n", bus->apb_clk);
+#endif // CONFIG_OF
+
+ gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
+ if (IS_ERR(gcr_regmap)) {
+ dev_err(bus->dev, "%s: failed to find nuvoton,npcm750-gcr\n",
+ __func__);
+ return IS_ERR(gcr_regmap);
+ }
+ regmap_write(gcr_regmap, NPCM_I2CSEGCTL, I2CSEGCTL_VAL);
+ dev_dbg(bus->dev, "I2C%d: gcr mapped\n", bus->num);
+
+ clk_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-clk");
+ if (IS_ERR(clk_regmap)) {
+ dev_err(bus->dev, "%s: failed to find nuvoton,npcm750-clk\n",
+ __func__);
+ return IS_ERR(clk_regmap);
+ }
+ dev_dbg(bus->dev, "I2C%d: clk mapped\n", bus->num);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ dev_dbg(bus->dev, "resource: %pR\n", res);
+ bus->reg = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR((bus)->reg))
+ return PTR_ERR((bus)->reg);
+
+ // Initialize the I2C adapter
+ spin_lock_init(&bus->lock);
+ init_completion(&bus->cmd_complete);
+
+ adap = &bus->adap;
+ adap->owner = THIS_MODULE;
+ adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD | I2C_CLIENT_SLAVE;
+ adap->retries = 3;
+ adap->timeout = HZ;
+ adap->algo = &npcm_i2c_algo;
+ adap->quirks = &npcm_i2c_quirks;
+ adap->algo_data = bus;
+ adap->dev.parent = &pdev->dev;
+ adap->dev.of_node = pdev->dev.of_node;
+ adap->nr = pdev->id;
+
+ bus->slave = NULL;
+
+ bus->irq = platform_get_irq(pdev, 0);
+ if (bus->irq < 0) {
+ dev_err(bus->dev, "I2C platform_get_irq error\n");
+ return -ENODEV;
+ }
+ dev_dbg(bus->dev, "irq = %d\n", bus->irq);
+
+ ret = devm_request_irq(&pdev->dev, bus->irq, npcm_i2c_bus_irq, 0,
+ dev_name(&pdev->dev), (void *)bus);
+
+ if (ret) {
+ dev_err(&pdev->dev, "I2C%d: request_irq fail\n", bus->num);
+ return ret;
+ }
+
+ ret = __npcm_i2c_init(bus, pdev);
+ if (ret < 0)
+ return ret;
+
+ ret = npcm_i2c_recovery_init(adap);
+ if (ret)
+ return ret;
+
+ i2c_set_adapdata(adap, bus);
+
+ snprintf(bus->adap.name, sizeof(bus->adap.name), "Nuvoton i2c");
+
+ ret = i2c_add_numbered_adapter(&bus->adap);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "I2C%d: i2c_add_numbered_adapter fail\n",
+ bus->num);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, bus);
+
+ pr_info("npcm7xx I2C bus %d is registered\n", bus->adap.nr);
+
+ return 0;
+}
+
+static int npcm_i2c_remove_bus(struct platform_device *pdev)
+{
+ unsigned long lock_flags;
+ struct npcm_i2c *bus = platform_get_drvdata(pdev);
+
+ spin_lock_irqsave(&bus->lock, lock_flags);
+ npcm_i2c_disable(bus);
+ spin_unlock_irqrestore(&bus->lock, lock_flags);
+ i2c_del_adapter(&bus->adap);
+
+ return 0;
+}
+
+static const struct of_device_id npcm_i2c_bus_of_table[] = {
+ { .compatible = "nuvoton,npcm750-i2c", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, npcm_i2c_bus_of_table);
+
+static struct platform_driver npcm_i2c_bus_driver = {
+ .probe = npcm_i2c_probe_bus,
+ .remove = npcm_i2c_remove_bus,
+ .driver = {
+ .name = "nuvoton-i2c",
+ .of_match_table = npcm_i2c_bus_of_table,
+ }
+};
+module_platform_driver(npcm_i2c_bus_driver);
+
+MODULE_AUTHOR("Avi Fishman <avi.fishman@gmail.com>");
+MODULE_AUTHOR("Tali Perry <tali.perry@nuvoton.com>");
+MODULE_AUTHOR("Tyrone Ting <kfting@nuvoton.com>");
+MODULE_DESCRIPTION("Nuvoton I2C Bus Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION("0.1.1");
+
--
2.22.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v8 3/3] i2c: npcm7xx: Add support for slave mode for Nuvoton
2020-03-01 22:31 [PATCH v8 0/3] i2c: npcm: add NPCM i2c controller driver Tali Perry
2020-03-01 22:31 ` [PATCH v8 1/3] dt-bindings: i2c: npcm7xx: add NPCM I2C controller Tali Perry
2020-03-01 22:32 ` [PATCH v8 2/3] i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver Tali Perry
@ 2020-03-01 22:32 ` Tali Perry
2 siblings, 0 replies; 5+ messages in thread
From: Tali Perry @ 2020-03-01 22:32 UTC (permalink / raw)
To: brendanhiggins, avifishman70, tmaimon77, kfting, venture, yuenn,
benjaminfair, robh+dt, wsa, andriy.shevchenko
Cc: linux-arm-kernel, linux-i2c, openbmc, devicetree, linux-kernel,
Tali Perry
Add support for slave mode for Nuvoton
NPCM BMC I2C controller driver.
Signed-off-by: Tali Perry <tali.perry1@gmail.com>
---
drivers/i2c/busses/i2c-npcm7xx.c | 602 +++++++++++++++++++++++++++++++
1 file changed, 602 insertions(+)
diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index cef5288f0394..06de2454215d 100644
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -65,6 +65,24 @@ enum i2c_state {
I2C_STOP_PENDING
};
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+// Module supports setting multiple own slave addresses
+enum i2c_addr {
+ I2C_SLAVE_ADDR1 = 0,
+ I2C_SLAVE_ADDR2,
+ I2C_SLAVE_ADDR3,
+ I2C_SLAVE_ADDR4,
+ I2C_SLAVE_ADDR5,
+ I2C_SLAVE_ADDR6,
+ I2C_SLAVE_ADDR7,
+ I2C_SLAVE_ADDR8,
+ I2C_SLAVE_ADDR9,
+ I2C_SLAVE_ADDR10,
+ I2C_GC_ADDR,
+ I2C_ARP_ADDR
+};
+#endif
+
// init register and default value required to enable module
#define NPCM_I2CSEGCTL 0xE4
#define I2CSEGCTL_VAL 0x0333F000
@@ -92,6 +110,14 @@ enum i2c_state {
#define NPCM_I2CADDR6 0x16
#define NPCM_I2CADDR10 0x17
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+// I2CADDR array: because the addr regs are sprinkled all over the address space
+const int npcm_i2caddr[10] = {NPCM_I2CADDR1, NPCM_I2CADDR2, NPCM_I2CADDR3,
+ NPCM_I2CADDR4, NPCM_I2CADDR5, NPCM_I2CADDR6,
+ NPCM_I2CADDR7, NPCM_I2CADDR8, NPCM_I2CADDR9,
+ NPCM_I2CADDR10};
+#endif
+
#define NPCM_I2CCTL4 0x1A
#define NPCM_I2CCTL5 0x1B
#define NPCM_I2CSCLLT 0x1C // SCL Low Time
@@ -310,6 +336,26 @@ struct npcm_i2c {
unsigned long bus_freq; // in kHz
u32 xmits;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ u8 own_slave_addr;
+ struct i2c_client *slave;
+
+ // currently I2C slave IF only supports single byte operations.
+ // in order to utilyze the npcm HW FIFO, the driver will ask for 16bytes
+ // at a time, pack them in buffer, and then transmit them all together
+ // to the FIFO and onward to the bus .
+ // NACK on read will be once reached to bus->adap->quirks->max_read_len
+ // sending a NACK whever the backend requests for it is not supported.
+
+ // This module can be master and slave at the same time. separate ptrs
+ // and counters:
+ int slv_rd_size;
+ int slv_rd_ind;
+ int slv_wr_size;
+ int slv_wr_ind;
+ u8 slv_rd_buf[I2C_HW_FIFO_SIZE];
+ u8 slv_wr_buf[I2C_HW_FIFO_SIZE];
+#endif
};
static inline void npcm_i2c_select_bank(struct npcm_i2c *bus,
@@ -587,6 +633,13 @@ static void npcm_i2c_reset(struct npcm_i2c *bus)
// Clear all fifo bits:
iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (bus->slave) {
+ npcm_i2c_slave_enable_l(bus, I2C_SLAVE_ADDR1, bus->slave->addr,
+ true);
+ }
+#endif
+
bus->state = I2C_IDLE;
}
@@ -684,6 +737,36 @@ static void npcm_i2c_write_to_fifo_master(struct npcm_i2c *bus,
}
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static void npcm_i2c_write_to_fifo_slave(struct npcm_i2c *bus,
+ u16 max_bytes_to_send)
+{
+ // Fill the FIFO, while the FIFO is not full and there are more bytes to
+ // write
+ npcm_i2c_clear_fifo_int(bus);
+ npcm_i2c_clear_tx_fifo(bus);
+ iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
+
+ if (max_bytes_to_send == 0)
+ return;
+
+ while ((max_bytes_to_send--) && (I2C_HW_FIFO_SIZE -
+ npcm_i2c_get_fifo_fullness(bus))) {
+ if (bus->slv_wr_size > 0) {
+ npcm_i2c_wr_byte(bus,
+ bus->slv_wr_buf[bus->slv_wr_ind %
+ I2C_HW_FIFO_SIZE]);
+ bus->slv_wr_ind = (bus->slv_wr_ind + 1) %
+ I2C_HW_FIFO_SIZE;
+ bus->slv_wr_size--; // size indicates the # of bytes in
+ // the SW FIFO, not HW.
+ } else {
+ break;
+ }
+ }
+}
+#endif
+
// configure the FIFO before using it. If nread is -1 RX FIFO will not be
// configured. same for nwrite
static void npcm_i2c_set_fifo(struct npcm_i2c *bus, int nread, int nwrite)
@@ -740,6 +823,18 @@ static void npcm_i2c_read_from_fifo(struct npcm_i2c *bus, u8 bytes_in_fifo)
if (bus->rd_ind < bus->rd_size)
bus->rd_buf[bus->rd_ind++] = data;
} else { // I2C_SLAVE:
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (bus->slave) {
+ bus->slv_rd_buf[bus->slv_rd_ind %
+ I2C_HW_FIFO_SIZE] = data;
+ bus->slv_rd_ind++;
+ if (bus->slv_rd_ind == 1 && bus->read_block_use)
+ // 1st byte is length in block protocol
+ bus->slv_rd_size = data +
+ (u8)bus->PEC_use +
+ (u8)bus->read_block_use;
+ }
+#endif
}
}
}
@@ -763,6 +858,491 @@ static int npcm_i2c_master_abort(struct npcm_i2c *bus)
return ret;
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static irqreturn_t npcm_i2c_bus_irq(int irq, void *dev_id);
+
+static int npcm_i2c_slave_enable_l(struct npcm_i2c *bus,
+ enum i2c_addr addr_type, u8 addr,
+ bool enable)
+{
+ u8 slave_addr_reg = FIELD_PREP(NPCM_I2CADDR_A, addr) |
+ FIELD_PREP(NPCM_I2CADDR_SAEN, enable);
+
+ if (addr_type == I2C_GC_ADDR) {
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) &
+ ~NPCM_I2CCTL1_GCMEN) |
+ FIELD_PREP(NPCM_I2CCTL1_GCMEN, enable),
+ bus->reg + NPCM_I2CCTL1);
+ return 0;
+ }
+ if (addr_type == I2C_ARP_ADDR) {
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL3) &
+ ~I2CCTL3_ARPMEN) |
+ FIELD_PREP(I2CCTL3_ARPMEN, enable),
+ bus->reg + NPCM_I2CCTL3);
+ return 0;
+ }
+ if (addr_type >= I2C_ARP_ADDR)
+ return -EFAULT;
+
+ // select bank 0 for address 3 to 10
+ if (addr_type > I2C_SLAVE_ADDR2)
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+
+ // Set and enable the address
+ iowrite8(slave_addr_reg, bus->reg + npcm_i2caddr[(int)addr_type]);
+
+ // enable interrupt on slave match:
+ iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) | NPCM_I2CCTL1_NMINTE) &
+ ~NPCM_I2CCTL1_RWS_FIELDS, bus->reg + NPCM_I2CCTL1);
+
+ if (addr_type > I2C_SLAVE_ADDR2)
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+ return 0;
+}
+
+static u8 npcm_i2c_get_slave_addr(struct npcm_i2c *bus,
+ enum i2c_addr addr_type)
+{
+ u8 slave_add;
+
+ // select bank 0 for address 3 to 10
+ if (addr_type > I2C_SLAVE_ADDR2)
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+
+ slave_add = ioread8(bus->reg + npcm_i2caddr[(int)addr_type]);
+
+ if (addr_type > I2C_SLAVE_ADDR2)
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ return slave_add;
+}
+
+static int npcm_i2c_remove_slave_addr(struct npcm_i2c *bus, u8 slave_add)
+{
+ int i;
+
+ slave_add |= 0x80; //Set the enable bit
+
+ npcm_i2c_select_bank(bus, I2C_BANK_0);
+
+ for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OF_ADDR; i++) {
+ if (ioread8(bus->reg + npcm_i2caddr[i]) == slave_add)
+ iowrite8(0, bus->reg + npcm_i2caddr[i]);
+ }
+
+ npcm_i2c_select_bank(bus, I2C_BANK_1);
+
+ return 0;
+}
+
+static int npcm_i2c_slave_get_wr_buf(struct npcm_i2c *bus)
+{
+ u8 value = 0;
+ int ret = bus->slv_wr_ind;
+ int i;
+
+ // fill a cyclic buffer
+ for (i = 0; i < I2C_HW_FIFO_SIZE; i++) {
+ if (bus->slv_wr_size >= I2C_HW_FIFO_SIZE)
+ break;
+ i2c_slave_event(bus->slave, I2C_SLAVE_READ_REQUESTED, &value);
+ bus->slv_wr_buf[(bus->slv_wr_ind + bus->slv_wr_size) %
+ I2C_HW_FIFO_SIZE] = value;
+ bus->slv_wr_size++;
+ i2c_slave_event(bus->slave, I2C_SLAVE_READ_PROCESSED, &value);
+ }
+ return I2C_HW_FIFO_SIZE - ret;
+}
+
+static void npcm_i2c_slave_send_rd_buf(struct npcm_i2c *bus)
+{
+ int i;
+
+ for (i = 0; i < bus->slv_rd_ind; i++)
+ i2c_slave_event(bus->slave, I2C_SLAVE_WRITE_RECEIVED,
+ &bus->slv_rd_buf[i]);
+
+ // once we send bytes up, need to reset the counter of the wr buf
+ // got data from master (new offset in device), ignore wr fifo:
+ if (bus->slv_rd_ind) {
+ bus->slv_wr_size = 0;
+ bus->slv_wr_ind = 0;
+ }
+
+ bus->slv_rd_ind = 0;
+ bus->slv_rd_size = bus->adap.quirks->max_read_len;
+
+ npcm_i2c_clear_fifo_int(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+}
+
+static bool npcm_i2c_slave_receive(struct npcm_i2c *bus, u16 nread,
+ u8 *read_data)
+{
+ bus->state = I2C_OPER_STARTED;
+ bus->operation = I2C_READ_OPER;
+ bus->slv_rd_size = nread;
+ bus->slv_rd_ind = 0;
+
+ iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
+ iowrite8(I2C_HW_FIFO_SIZE, bus->reg + NPCM_I2CRXF_CTL);
+
+ npcm_i2c_clear_tx_fifo(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+
+ return true;
+}
+
+static bool npcm_i2c_slave_xmit(struct npcm_i2c *bus, u16 nwrite,
+ u8 *write_data)
+{
+ if (nwrite == 0)
+ return false;
+
+ bus->state = I2C_OPER_STARTED;
+ bus->operation = I2C_WRITE_OPER;
+
+ // get the next buffer
+ npcm_i2c_slave_get_wr_buf(bus);
+
+ if (nwrite > 0)
+ npcm_i2c_write_to_fifo_slave(bus, nwrite);
+
+ return true;
+}
+
+// currently slave IF only supports single byte operations.
+// in order to utilyze the npcm HW FIFO, the driver will ask for 16 bytes
+// at a time, pack them in buffer, and then transmit them all together
+// to the FIFO and onward to the bus.
+// NACK on read will be once reached to bus->adap->quirks->max_read_len.
+// sending a NACK wherever the backend requests for it is not supported.
+// the next two functions allow reading to local buffer before writing it all
+// to the HW FIFO.
+// ret val: number of bytes read form the IF:
+
+static int npcm_i2c_slave_wr_buf_sync(struct npcm_i2c *bus)
+{
+ int left_in_fifo = FIELD_GET(NPCM_I2CTXF_STS_TX_BYTES,
+ ioread8(bus->reg + NPCM_I2CTXF_STS));
+
+ if (left_in_fifo >= I2C_HW_FIFO_SIZE)
+ return left_in_fifo;
+
+ if (bus->slv_wr_size >= I2C_HW_FIFO_SIZE)
+ return left_in_fifo; // fifo already full
+
+ // update the wr fifo ind, back to the untransmitted bytes:
+ bus->slv_wr_ind = bus->slv_wr_ind - left_in_fifo;
+ bus->slv_wr_size = bus->slv_wr_size + left_in_fifo;
+
+ if (bus->slv_wr_ind < 0)
+ bus->slv_wr_ind += I2C_HW_FIFO_SIZE;
+
+ return left_in_fifo;
+}
+
+static void npcm_i2c_slave_rd_wr(struct npcm_i2c *bus)
+{
+ if (FIELD_GET(NPCM_I2CST_XMIT, ioread8(bus->reg + NPCM_I2CST))) {
+ // Slave got an address match with direction bit 1 so
+ // it should transmit data
+ // Write till the master will NACK
+ bus->operation = I2C_WRITE_OPER;
+ npcm_i2c_slave_xmit(bus,
+ bus->adap.quirks->max_write_len,
+ bus->slv_wr_buf);
+ } else {
+ // Slave got an address match with direction bit 0
+ // so it should receive data.
+ // this module does not support saying no to bytes.
+ // it will always ACK.
+ bus->operation = I2C_READ_OPER;
+ npcm_i2c_read_from_fifo(bus, npcm_i2c_get_fifo_fullness(bus));
+ bus->stop_ind = I2C_SLAVE_RCV_IND;
+ npcm_i2c_slave_send_rd_buf(bus);
+ npcm_i2c_slave_receive(bus,
+ bus->adap.quirks->max_read_len,
+ bus->slv_rd_buf);
+ }
+}
+
+static irqreturn_t npcm_i2c_int_slave_handler(struct npcm_i2c *bus)
+{
+ irqreturn_t ret = IRQ_NONE;
+ u8 i2cst = ioread8(bus->reg + NPCM_I2CST);
+ // Slave: A NACK has occurred
+ if (FIELD_GET(NPCM_I2CST_NEGACK, i2cst)) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NACK);
+ bus->stop_ind = I2C_NACK_IND;
+ npcm_i2c_slave_wr_buf_sync(bus);
+ if (bus->fifo_use)
+ // clear the FIFO
+ iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_I2CFIF_CTS);
+
+ // In slave write, NACK is OK, otherwise it is a problem
+ bus->stop_ind = I2C_NO_STATUS_IND;
+ bus->operation = I2C_NO_OPER;
+ bus->own_slave_addr = 0xFF;
+
+ // Slave has to wait for I2C_STOP to decide this is the end
+ // of the transaction.
+ // Therefore transaction is not yet considered as done
+ iowrite8(NPCM_I2CST_NEGACK, bus->reg + NPCM_I2CST);
+
+ ret = IRQ_HANDLED;
+ }
+
+ // Slave mode: a Bus Error (BER) has been identified
+ if (FIELD_GET(NPCM_I2CST_BER, i2cst)) {
+ // Check whether bus arbitration or Start or Stop during data
+ // xfer bus arbitration problem should not result in recovery
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_BER_SLV);
+ bus->stop_ind = I2C_BUS_ERR_IND;
+
+ // wait for bus busy before clear fifo
+ iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO, bus->reg + NPCM_I2CFIF_CTS);
+
+ bus->state = I2C_IDLE;
+
+ // in BER case we might get 2 interrupts: one for slave one for
+ // master ( for a channel which is master\slave switching)
+ if (completion_done(&bus->cmd_complete) == false) {
+ bus->cmd_err = -EIO;
+ complete(&bus->cmd_complete);
+ }
+ bus->own_slave_addr = 0xFF;
+ iowrite8(NPCM_I2CST_BER, bus->reg + NPCM_I2CST);
+ ret = IRQ_HANDLED;
+ }
+
+ // A Slave Stop Condition has been identified
+ if (FIELD_GET(NPCM_I2CST_SLVSTP, i2cst)) {
+ int bytes_in_fifo = npcm_i2c_get_fifo_fullness(bus);
+
+ bus->stop_ind = I2C_SLAVE_DONE_IND;
+
+ if (bus->operation == I2C_READ_OPER) {
+ npcm_i2c_read_from_fifo(bus, bytes_in_fifo);
+
+ // Slave done transmitting or receiving
+ // if the buffer is empty nothing will be sent
+ }
+
+ // Slave done transmitting or receiving
+ // if the buffer is empty nothing will be sent
+ npcm_i2c_slave_send_rd_buf(bus);
+
+ bus->stop_ind = I2C_NO_STATUS_IND;
+
+ // Note, just because we got here, it doesn't mean we through
+ // away the wr buffer.
+ // we keep it until the next received offset.
+ bus->operation = I2C_NO_OPER;
+ bus->int_cnt = 0;
+ bus->event_log_prev = bus->event_log;
+ bus->event_log = 0;
+ bus->own_slave_addr = 0xFF;
+
+ i2c_slave_event(bus->slave, I2C_SLAVE_STOP, 0);
+
+ iowrite8(NPCM_I2CST_SLVSTP, bus->reg + NPCM_I2CST);
+
+ if (bus->fifo_use) {
+ npcm_i2c_clear_fifo_int(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+ npcm_i2c_clear_tx_fifo(bus);
+
+ iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_I2CFIF_CTS);
+ }
+
+ bus->state = I2C_IDLE;
+ ret = IRQ_HANDLED;
+ }
+
+ // restart condition occurred and Rx-FIFO was not empty
+ if (bus->fifo_use && FIELD_GET(NPCM_I2CFIF_CTS_SLVRSTR,
+ ioread8(bus->reg + NPCM_I2CFIF_CTS))) {
+ bus->stop_ind = I2C_SLAVE_RESTART_IND;
+
+ bus->master_or_slave = I2C_SLAVE;
+
+ if (bus->operation == I2C_READ_OPER)
+ npcm_i2c_read_from_fifo(bus,
+ npcm_i2c_get_fifo_fullness(bus)
+ );
+
+ bus->operation = I2C_WRITE_OPER;
+
+ iowrite8(0, bus->reg + NPCM_I2CRXF_CTL);
+
+ iowrite8(NPCM_I2CFIF_CTS_CLR_FIFO | NPCM_I2CFIF_CTS_SLVRSTR |
+ NPCM_I2CFIF_CTS_RXF_TXE, bus->reg + NPCM_I2CFIF_CTS);
+
+ npcm_i2c_slave_rd_wr(bus);
+
+ ret = IRQ_HANDLED;
+ }
+
+ // A Slave Address Match has been identified
+ if (FIELD_GET(NPCM_I2CST_NMATCH, i2cst)) {
+ u8 info = 0;
+
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NMATCH_SLV);
+ // Address match automatically implies slave mode
+ bus->master_or_slave = I2C_SLAVE;
+
+ npcm_i2c_clear_fifo_int(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+ npcm_i2c_clear_tx_fifo(bus);
+ iowrite8(0, bus->reg + NPCM_I2CTXF_CTL);
+ iowrite8(I2C_HW_FIFO_SIZE, bus->reg + NPCM_I2CRXF_CTL);
+
+ if (FIELD_GET(NPCM_I2CST_XMIT, i2cst)) {
+ bus->operation = I2C_WRITE_OPER;
+ } else {
+ i2c_slave_event(bus->slave, I2C_SLAVE_WRITE_REQUESTED,
+ &info);
+ bus->operation = I2C_READ_OPER;
+ }
+
+ if (bus->own_slave_addr == 0xFF) { // unknown address
+ // Check which type of address match
+ if (FIELD_GET(NPCM_I2CCST_MATCH,
+ ioread8(bus->reg + NPCM_I2CCST))) {
+ u16 addr;
+ enum i2c_addr eaddr;
+
+ addr = ((ioread8(bus->reg + NPCM_I2CCST3) &
+ 0x7) << 7) |
+ (ioread8(bus->reg + NPCM_I2CCST2) &
+ 0x7F);
+
+ info = ffs(addr);
+ eaddr = (enum i2c_addr)info;
+
+ addr = FIELD_GET(NPCM_I2CADDR_A,
+ npcm_i2c_get_slave_addr(bus,
+ eaddr)
+ );
+ bus->own_slave_addr = addr;
+
+ if (bus->PEC_mask & BIT(info))
+ bus->PEC_use = true;
+ else
+ bus->PEC_use = false;
+ } else {
+ if (FIELD_GET(NPCM_I2CCST_GCMATCH,
+ ioread8(bus->reg + NPCM_I2CCST)))
+ bus->own_slave_addr = 0;
+ if (FIELD_GET(NPCM_I2CCST_ARPMATCH,
+ ioread8(bus->reg + NPCM_I2CCST)))
+ bus->own_slave_addr = 0x61;
+ }
+ } else {
+ // Slave match can happen in two options:
+ // 1. Start, SA, read (slave read without further ado)
+ // 2. Start, SA, read, data, restart, SA, read, ...
+ // (slave read in fragmented mode)
+ // 3. Start, SA, write, data, restart, SA, read, ..
+ // (regular write-read mode)
+ if ((bus->state == I2C_OPER_STARTED &&
+ bus->operation == I2C_READ_OPER &&
+ bus->stop_ind == I2C_SLAVE_XMIT_IND) ||
+ bus->stop_ind == I2C_SLAVE_RCV_IND) {
+ // slave transmit after slave receive w/o Slave
+ // Stop implies repeated start
+ bus->stop_ind = I2C_SLAVE_RESTART_IND;
+ }
+ }
+
+ if (FIELD_GET(NPCM_I2CST_XMIT, i2cst))
+ bus->stop_ind = I2C_SLAVE_XMIT_IND;
+ else
+ bus->stop_ind = I2C_SLAVE_RCV_IND;
+
+ bus->state = I2C_SLAVE_MATCH;
+
+ npcm_i2c_slave_rd_wr(bus);
+
+ iowrite8(NPCM_I2CST_NMATCH, bus->reg + NPCM_I2CST);
+ ret = IRQ_HANDLED;
+ }
+
+ // Slave SDA status is set - transmit or receive, slave
+ if (FIELD_GET(NPCM_I2CST_SDAST, i2cst) ||
+ (bus->fifo_use &&
+ (npcm_i2c_tx_fifo_empty(bus) || npcm_i2c_rx_fifo_full(bus)))) {
+ npcm_i2c_slave_rd_wr(bus);
+
+ iowrite8(NPCM_I2CST_SDAST, bus->reg + NPCM_I2CST);
+
+ ret = IRQ_HANDLED;
+ } //SDAST
+
+ return ret;
+}
+
+static int npcm_i2c_reg_slave(struct i2c_client *client)
+{
+ unsigned long lock_flags;
+ struct npcm_i2c *bus = i2c_get_adapdata(client->adapter);
+
+ bus->slave = client;
+
+ if (!bus->slave)
+ return -EINVAL;
+
+ if (client->flags & I2C_CLIENT_TEN)
+ return -EAFNOSUPPORT;
+
+ spin_lock_irqsave(&bus->lock, lock_flags);
+
+ npcm_i2c_init_params(bus);
+ bus->slv_rd_size = 0;
+ bus->slv_wr_size = 0;
+ bus->slv_rd_ind = 0;
+ bus->slv_wr_ind = 0;
+ if (client->flags & I2C_CLIENT_PEC)
+ bus->PEC_use = true;
+
+ dev_info(bus->dev, "I2C%d register slave SA=0x%x, PEC=%d\n", bus->num,
+ client->addr, bus->PEC_use);
+
+ npcm_i2c_slave_enable_l(bus, I2C_SLAVE_ADDR1, client->addr, true);
+
+ npcm_i2c_clear_fifo_int(bus);
+ npcm_i2c_clear_rx_fifo(bus);
+ npcm_i2c_clear_tx_fifo(bus);
+
+ spin_unlock_irqrestore(&bus->lock, lock_flags);
+
+ return 0;
+}
+
+static int npcm_i2c_unreg_slave(struct i2c_client *client)
+{
+ struct npcm_i2c *bus = client->adapter->algo_data;
+ unsigned long lock_flags;
+
+ spin_lock_irqsave(&bus->lock, lock_flags);
+ if (!bus->slave) {
+ spin_unlock_irqrestore(&bus->lock, lock_flags);
+ return -EINVAL;
+ }
+
+ npcm_i2c_remove_slave_addr(bus, client->addr);
+
+ bus->slave = NULL;
+ spin_unlock_irqrestore(&bus->lock, lock_flags);
+
+ return 0;
+}
+#endif // CONFIG_I2C_SLAVE
+
static void npcm_i2c_master_fifo_read(struct npcm_i2c *bus)
{
int rcount;
@@ -1512,6 +2092,14 @@ static irqreturn_t npcm_i2c_bus_irq(int irq, void *dev_id)
if (ret == IRQ_HANDLED)
return ret;
}
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ if (bus->slave) {
+ bus->master_or_slave = I2C_SLAVE;
+ ret = npcm_i2c_int_slave_handler(bus);
+ if (ret == IRQ_HANDLED)
+ return ret;
+ }
+#endif
return IRQ_HANDLED;
}
@@ -1711,6 +2299,13 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
if (bus->cmd_err == -EAGAIN)
i2c_recover_bus(adap);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ // reenable slave if it was enabled
+ if (bus->slave)
+ iowrite8((bus->slave->addr & 0x7F) | NPCM_I2CADDR_SAEN,
+ bus->reg + NPCM_I2CADDR1);
+#endif
+
// If nothing went wrong, return number of messages x-ferred.
if (ret >= 0)
return num;
@@ -1724,6 +2319,9 @@ static u32 npcm_i2c_functionality(struct i2c_adapter *adap)
I2C_FUNC_SMBUS_EMUL |
I2C_FUNC_SMBUS_BLOCK_DATA |
I2C_FUNC_SMBUS_PEC
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ | I2C_FUNC_SLAVE
+#endif
;
}
@@ -1737,6 +2335,10 @@ static const struct i2c_adapter_quirks npcm_i2c_quirks = {
static const struct i2c_algorithm npcm_i2c_algo = {
.master_xfer = npcm_i2c_master_xfer,
.functionality = npcm_i2c_functionality,
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+ .reg_slave = npcm_i2c_reg_slave,
+ .unreg_slave = npcm_i2c_unreg_slave,
+#endif
};
static int npcm_i2c_probe_bus(struct platform_device *pdev)
--
2.22.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v8 2/3] i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver
2020-03-01 22:32 ` [PATCH v8 2/3] i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver Tali Perry
@ 2020-03-02 10:50 ` Andy Shevchenko
0 siblings, 0 replies; 5+ messages in thread
From: Andy Shevchenko @ 2020-03-02 10:50 UTC (permalink / raw)
To: Tali Perry
Cc: brendanhiggins, avifishman70, tmaimon77, kfting, venture, yuenn,
benjaminfair, robh+dt, wsa, linux-arm-kernel, linux-i2c, openbmc,
devicetree, linux-kernel
On Mon, Mar 02, 2020 at 12:32:00AM +0200, Tali Perry wrote:
> Add Nuvoton NPCM BMC I2C controller driver.
> +#include <linux/bitfield.h>
> +#include <linux/clk.h>
> +#include <linux/errno.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/irq.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/jiffies.h>
...
> +enum i2c_mode {
> + I2C_MASTER,
> + I2C_SLAVE
If it's not a terminator line (like MAX or something like that) it's better to
have comma at the end. This applies to all enum:s in your code.
> +};
...
> +// I2Cus Operation type values
It's funny style of comments when you have different for multi-line ones. I
don't know Wolfram's opinion on that, but at least for me looks like a bit of
consistency should be applied.
Also in some of them you missed English grammar / punctuation.
> +enum i2c_oper {
> + I2C_NO_OPER = 0,
> + I2C_WRITE_OPER = 1,
> + I2C_READ_OPER = 2
If it's not hardware related values, why we need to define them explicitly?
> +};
...
> +#define NPCM_I2CCTL1_RWS_FIELDS (NPCM_I2CCTL1_START | NPCM_I2CCTL1_STOP | \
> + NPCM_I2CCTL1_ACK)
Better do like
#define FOO \
(BAR | BAZ)
...
> +const unsigned int RETRIES_NUM = 10000;
> +const unsigned int I2C_FREQ_MIN = 10;
> +const unsigned int I2C_FREQ_MAX = 1000;
> +const unsigned int I2C_FREQ_100KHZ = 100;
> +const unsigned int I2C_FREQ_400KHZ = 400;
> +const unsigned int I2C_FREQ_1MHZ = 1000;
> +const unsigned int SCLFRQ_MIN = 10;
> +const unsigned int SCLFRQ_MAX = 511;
> +const unsigned int I2C_NUM_OF_ADDR = 10;
Hmm... Why they are not defines?
...
> +// Status of one I2C module
> +struct npcm_i2c {
> + struct i2c_adapter adap;
> + struct device *dev;
> + unsigned char __iomem *reg;
> + spinlock_t lock; /* IRQ synchronization */
Perhaps you describe all of the fields in kernel-doc format?
> + struct completion cmd_complete;
> + int irq;
> + int cmd_err;
> + struct i2c_msg *msgs;
> + int msgs_num;
> + int num;
> + u32 apb_clk;
> + struct i2c_bus_recovery_info rinfo;
> + enum i2c_state state;
> + enum i2c_oper operation;
> + enum i2c_mode master_or_slave;
> + enum i2c_state_ind stop_ind;
> + u8 dest_addr;
> + u8 *rd_buf;
> + u16 rd_size;
> + u16 rd_ind;
> + u8 *wr_buf;
> + u16 wr_size;
> + u16 wr_ind;
> + bool fifo_use;
> +
> + // PEC bit mask per slave address.
> + // 1: use PEC for this address,
> + // 0: do not use PEC for this address
Ditto.
> + u16 PEC_mask;
> + bool PEC_use;
> + bool read_block_use;
> + u8 int_cnt;
> + u32 event_log;
> + u32 event_log_prev;
> + u32 clk_period_us;
> + unsigned long int_time_stamp;
> + unsigned long bus_freq; // in kHz
> + u32 xmits;
> +
> +};
...
> +static inline void npcm_i2c_select_bank(struct npcm_i2c *bus,
> + enum i2c_bank bank)
> +{
> + if (bank == I2C_BANK_0)
> + iowrite8(ioread8(bus->reg + NPCM_I2CCTL3) & ~I2CCTL3_BNK_SEL,
> + bus->reg + NPCM_I2CCTL3);
> + else
> + iowrite8(ioread8(bus->reg + NPCM_I2CCTL3) | I2CCTL3_BNK_SEL,
> + bus->reg + NPCM_I2CCTL3);
Usual patter (better to read) is
u8 value;
value = ioread8(...);
if (a)
val ...;
else
val ...;
iowrite8(val, ...);
> +}
...
> +static inline void npcm_i2c_rd_byte(struct npcm_i2c *bus, u8 *data)
> +{
> + *data = ioread8(bus->reg + NPCM_I2CSDA);
> +}
Hmm... why not u8 as return type?
...
> +static inline u16 npcm_i2c_get_index(struct npcm_i2c *bus)
> +{
> + u16 index = 0;
> +
> + if (bus->operation == I2C_READ_OPER)
> + index = bus->rd_ind;
> + else if (bus->operation == I2C_WRITE_OPER)
> + index = bus->wr_ind;
> +
> + return index;
Why do you need temporary variable?
if (a)
return X;
if (b)
return Y;
return 0;
> +}
...
> +static inline bool npcm_i2c_is_quick(struct npcm_i2c *bus)
> +{
> + if (bus->wr_size == 0 && bus->rd_size == 0)
> + return true;
> + return false;
return bus->wr_size == 0 && bus->rd_size == 0;
> +}
...
> +static void npcm_i2c_disable(struct npcm_i2c *bus)
> +{
> + int i;
> +
> + // select bank 0 for I2C addresses
> + npcm_i2c_select_bank(bus, I2C_BANK_0);
> +
> + // Slave addresses removal
> + for (i = I2C_SLAVE_ADDR1; i < I2C_NUM_OF_ADDR; i++)
> + iowrite8(0, bus->reg + npcm_i2caddr[i]);
> +
> + npcm_i2c_select_bank(bus, I2C_BANK_1);
> +
> + // Disable module.
> + iowrite8(ioread8(bus->reg + NPCM_I2CCTL2) & ~I2CCTL2_ENABLE,
> + bus->reg + NPCM_I2CCTL2);
Usual pattern
value = ioread8(...);
value ...;
iowrite(value, ...);
> +
> + bus->state = I2C_DISABLE;
> +}
...
> +
> +static void npcm_i2c_enable(struct npcm_i2c *bus)
> +{
> + iowrite8((ioread8(bus->reg + NPCM_I2CCTL2) | I2CCTL2_ENABLE),
> + bus->reg + NPCM_I2CCTL2);
Ditto. Applies to all your code.
> +
> + bus->state = I2C_IDLE;
> +}
...
> +static bool npcm_i2c_wait_for_bus_free(struct npcm_i2c *bus, bool may_sleep)
> +{
> + int cnt = 0;
> + int max_count = 2; /* wait for 2 ms */
> +
> + if (may_sleep)
> + might_sleep();
> + else
> + max_count = max_count * 100; /* since each delay is 10 us */
> + while (ioread8(bus->reg + NPCM_I2CCST) & NPCM_I2CCST_BUSY) {
> + if (cnt < max_count) {
> + if (may_sleep)
> + msleep_interruptible(1);
> + else
> + udelay(10);
> + cnt++;
> +
> + } else {
> + bus->cmd_err = -EAGAIN;
> + return false;
> + }
> + }
NIH of readx_poll_timeout{_atomic}().
> + return true;
> +}
...
> +static inline void npcm_i2c_eob_int(struct npcm_i2c *bus, bool enable)
> +{
> + // Clear EO_BUSY pending bit:
> + iowrite8(ioread8(bus->reg + NPCM_I2CCST3) | NPCM_I2CCST3_EO_BUSY,
> + bus->reg + NPCM_I2CCST3);
> +
> + if (enable) {
> + iowrite8((ioread8(bus->reg + NPCM_I2CCTL1) |
> + NPCM_I2CCTL1_EOBINTE) & ~NPCM_I2CCTL1_RWS_FIELDS,
> + bus->reg + NPCM_I2CCTL1);
> + } else {
> + iowrite8(ioread8(bus->reg + NPCM_I2CCTL1) &
> + ~NPCM_I2CCTL1_EOBINTE & ~NPCM_I2CCTL1_RWS_FIELDS,
> + bus->reg + NPCM_I2CCTL1);
> + }
Hard to follow. See above comments.
> +}
...
> + return (bool)FIELD_GET(NPCM_I2CTXF_STS_TX_THST, tx_fifo_sts);
!! will do better than explicit casting.
Ditto for the rest.
...
> +static int npcm_i2c_slave_enable_l(struct npcm_i2c *bus,
> + enum i2c_addr addr_type, u8 addr,
> + bool enable);
Why is it here? Do you have recursion / circular dependency?
...
> + if (!msgs)
> + return;
Is it possible?
> + if (completion_done(&bus->cmd_complete) == true)
' == true' is redundant. Same for ' == false' (use ! instead).
> + return;
...
> +static void npcm_i2c_write_to_fifo_master(struct npcm_i2c *bus,
> + u16 max_bytes_to_send)
> +{
> + // Fill the FIFO, while the FIFO is not full and there are more bytes to
> + // write
> + if (max_bytes_to_send == 0)
> + return;
Duplicate check, thus redundant.
> + while ((max_bytes_to_send--) && (I2C_HW_FIFO_SIZE -
> + npcm_i2c_get_fifo_fullness(bus))) {
Badly formatted line. Moreover, too many parentheses.
> + if (bus->wr_ind < bus->wr_size)
> + npcm_i2c_wr_byte(bus, bus->wr_buf[bus->wr_ind++]);
> + else
> + npcm_i2c_wr_byte(bus, 0xFF);
> + }
> +}
...
> + rxf_ctl = min_t(u16, (u16)nread, (u16)I2C_HW_FIFO_SIZE);
Explicit casting when use min_t()? It's strange. Have you chance to read what
min_t() does?
...
> +
> +static int npcm_i2c_master_abort(struct npcm_i2c *bus)
> +{
> + int ret = 0;
I don't see why this variable is needed.
> +
> + NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_ABORT);
> +
> + // Only current master is allowed to issue Stop Condition
> + if (npcm_i2c_is_master(bus)) {
> + npcm_i2c_eob_int(bus, true);
> + npcm_i2c_master_stop(bus);
> +
> + // Clear NEGACK, STASTR and BER bits
> + iowrite8(NPCM_I2CST_BER | NPCM_I2CST_NEGACK | NPCM_I2CST_STASTR,
> + bus->reg + NPCM_I2CST);
> + }
> +
> + return ret;
> +}
...
> + pr_debug("i2c%d get SCL 0x%08X\n", bus->num, ret);
Do you need this in production code?
> + return (ret >> (offset)) & 0x01;
Too many parentheses, but why not simple
return !!(ret & BIT(offset));
?
Same for the rest similar code.
...
> +static int npcm_i2c_get_SDA(struct i2c_adapter *_adap)
> +{
> + unsigned int ret = 0;
> + struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
> + u32 offset = 0;
> +
> + offset = 0;
What the point?
> + ret = FIELD_GET(I2CCTL3_SDA_LVL, ioread32(bus->reg + NPCM_I2CCTL3));
> +
> + pr_debug("i2c%d get SDA 0x%08X\n", bus->num, ret);
> +
> + return (ret >> (offset)) & 0x01;
> +}
I (almost) stopped here, I thing this driver needs more work (style,
refactoring, etc) before real review.
...
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + dev_dbg(bus->dev, "resource: %pR\n", res);
> + bus->reg = devm_ioremap_resource(&pdev->dev, res);
devm_platform_ioremap_resource();
> + if (IS_ERR((bus)->reg))
> + return PTR_ERR((bus)->reg);
...
> + bus->irq = platform_get_irq(pdev, 0);
> + if (bus->irq < 0) {
> + dev_err(bus->dev, "I2C platform_get_irq error\n");
Redundant.
> + return -ENODEV;
> + }
...
> + dev_dbg(bus->dev, "irq = %d\n", bus->irq);
Why?! There are other means to get this information.
> + ret = devm_request_irq(&pdev->dev, bus->irq, npcm_i2c_bus_irq, 0,
> + dev_name(&pdev->dev), (void *)bus);
Explicit casting?!
...
> + pr_info("npcm7xx I2C bus %d is registered\n", bus->adap.nr);
Noise.
...
> +static const struct of_device_id npcm_i2c_bus_of_table[] = {
> + { .compatible = "nuvoton,npcm750-i2c", },
> + {},
For terminator line comma is redundant.
> +};
...
> +MODULE_VERSION("0.1.1");
What the point?
--
With Best Regards,
Andy Shevchenko
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2020-03-02 10:50 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-01 22:31 [PATCH v8 0/3] i2c: npcm: add NPCM i2c controller driver Tali Perry
2020-03-01 22:31 ` [PATCH v8 1/3] dt-bindings: i2c: npcm7xx: add NPCM I2C controller Tali Perry
2020-03-01 22:32 ` [PATCH v8 2/3] i2c: npcm7xx: Add Nuvoton NPCM I2C controller driver Tali Perry
2020-03-02 10:50 ` Andy Shevchenko
2020-03-01 22:32 ` [PATCH v8 3/3] i2c: npcm7xx: Add support for slave mode for Nuvoton Tali Perry
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