[PATCH v4 4/4] can: tcan4x5x: Add tcan4x5x driver to the kernel

Dan Murphy
2019-01-17T20:06:01Z

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

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

Signed-off-by: Dan Murphy <dmurphy@ti.com>
---
drivers/net/can/m_can/Kconfig | 6 +
drivers/net/can/m_can/tcan4x5x.c | 529 +++++++++++++++++++++++++++++++
2 files changed, 535 insertions(+)
create mode 100644 drivers/net/can/m_can/tcan4x5x.c

diff --git a/drivers/net/can/m_can/Kconfig b/drivers/net/can/m_can/Kconfig
index b1a9358b7660..b38959b3b8f1 100644
--- a/drivers/net/can/m_can/Kconfig
+++ b/drivers/net/can/m_can/Kconfig
@@ -15,3 +15,9 @@ config CAN_M_CAN_PLATFORM
tristate "Bosch M_CAN devices"
---help---
Say Y here if you want to support for Bosch M_CAN controller.
+
+config CAN_M_CAN_TCAN4X5X
+ depends on CAN_M_CAN
+ tristate "TCAN4X5X M_CAN device"
+ ---help---
+ Say Y here if you want to support for TI M_CAN controller.
diff --git a/drivers/net/can/m_can/tcan4x5x.c b/drivers/net/can/m_can/tcan4x5x.c
new file mode 100644
index 000000000000..3cd6cd5052b6
--- /dev/null
+++ b/drivers/net/can/m_can/tcan4x5x.c
@@ -0,0 +1,529 @@
+// SPDX-License-Identifier: GPL-2.0
+// SPI to CAN driver for the Texas Instruments TCAN4x5x
+// Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
+
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+#include <linux/regulator/consumer.h>
+#include <linux/gpio/consumer.h>
+
+#include "m_can_platform.h"
+
+#define DEVICE_NAME "tcan4x5x"
+#define TCAN4X5X_EXT_CLK_DEF 40000000
+
+#define TCAN4X5X_DEV_ID0 0x00
+#define TCAN4X5X_DEV_ID1 0x04
+#define TCAN4X5X_REV 0x08
+#define TCAN4X5X_STATUS 0x0C
+#define TCAN4X5X_ERROR_STATUS 0x10
+#define TCAN4X5X_CONTROL 0x14
+
+#define TCAN4X5X_CONFIG 0x800
+#define TCAN4X5X_TS_PRESCALE 0x804
+#define TCAN4X5X_TEST_REG 0x808
+#define TCAN4X5X_INT_FLAGS 0x820
+#define TCAN4X5X_MCAN_INT_REG 0x824
+#define TCAN4X5X_INT_EN 0x830
+
+
+/* Interrupt bits */
+#define TCAN4X5X_CANBUSTERMOPEN_INT_EN BIT(30)
+#define TCAN4X5X_CANHCANL_INT_EN BIT(29)
+#define TCAN4X5X_CANHBAT_INT_EN BIT(28)
+#define TCAN4X5X_CANLGND_INT_EN BIT(27)
+#define TCAN4X5X_CANBUSOPEN_INT_EN BIT(26)
+#define TCAN4X5X_CANBUSGND_INT_EN BIT(25)
+#define TCAN4X5X_CANBUSBAT_INT_EN BIT(24)
+#define TCAN4X5X_UVSUP_INT_EN BIT(22)
+#define TCAN4X5X_UVIO_INT_EN BIT(21)
+#define TCAN4X5X_TSD_INT_EN BIT(19)
+#define TCAN4X5X_ECCERR_INT_EN BIT(16)
+#define TCAN4X5X_CANINT_INT_EN BIT(15)
+#define TCAN4X5X_LWU_INT_EN BIT(14)
+#define TCAN4X5X_CANSLNT_INT_EN BIT(10)
+#define TCAN4X5X_CANDOM_INT_EN BIT(8)
+#define TCAN4X5X_CANBUS_ERR_INT_EN BIT(5)
+#define TCAN4X5X_BUS_FAULT BIT(4)
+#define TCAN4X5X_MCAN_INT BIT(1)
+#define TCAN4X5X_ENABLE_TCAN_INT (TCAN4X5X_MCAN_INT | \
+ TCAN4X5X_BUS_FAULT | \
+ TCAN4X5X_CANBUS_ERR_INT_EN | \
+ TCAN4X5X_CANINT_INT_EN)
+
+/* MCAN Interrupt bits */
+#define TCAN4X5X_MCAN_IR_ARA BIT(29)
+#define TCAN4X5X_MCAN_IR_PED BIT(28)
+#define TCAN4X5X_MCAN_IR_PEA BIT(27)
+#define TCAN4X5X_MCAN_IR_WD BIT(26)
+#define TCAN4X5X_MCAN_IR_BO BIT(25)
+#define TCAN4X5X_MCAN_IR_EW BIT(24)
+#define TCAN4X5X_MCAN_IR_EP BIT(23)
+#define TCAN4X5X_MCAN_IR_ELO BIT(22)
+#define TCAN4X5X_MCAN_IR_BEU BIT(21)
+#define TCAN4X5X_MCAN_IR_BEC BIT(20)
+#define TCAN4X5X_MCAN_IR_DRX BIT(19)
+#define TCAN4X5X_MCAN_IR_TOO BIT(18)
+#define TCAN4X5X_MCAN_IR_MRAF BIT(17)
+#define TCAN4X5X_MCAN_IR_TSW BIT(16)
+#define TCAN4X5X_MCAN_IR_TEFL BIT(15)
+#define TCAN4X5X_MCAN_IR_TEFF BIT(14)
+#define TCAN4X5X_MCAN_IR_TEFW BIT(13)
+#define TCAN4X5X_MCAN_IR_TEFN BIT(12)
+#define TCAN4X5X_MCAN_IR_TFE BIT(11)
+#define TCAN4X5X_MCAN_IR_TCF BIT(10)
+#define TCAN4X5X_MCAN_IR_TC BIT(9)
+#define TCAN4X5X_MCAN_IR_HPM BIT(8)
+#define TCAN4X5X_MCAN_IR_RF1L BIT(7)
+#define TCAN4X5X_MCAN_IR_RF1F BIT(6)
+#define TCAN4X5X_MCAN_IR_RF1W BIT(5)
+#define TCAN4X5X_MCAN_IR_RF1N BIT(4)
+#define TCAN4X5X_MCAN_IR_RF0L BIT(3)
+#define TCAN4X5X_MCAN_IR_RF0F BIT(2)
+#define TCAN4X5X_MCAN_IR_RF0W BIT(1)
+#define TCAN4X5X_MCAN_IR_RF0N BIT(0)
+#define TCAN4X5X_ENABLE_MCAN_INT (TCAN4X5X_MCAN_IR_TC | \
+ TCAN4X5X_MCAN_IR_RF0N | \
+ TCAN4X5X_MCAN_IR_RF1N | \
+ TCAN4X5X_MCAN_IR_RF0F | \
+ TCAN4X5X_MCAN_IR_RF1F)
+#define TCAN4X5X_MRAM_START 0x8000
+#define TCAN4X5X_MCAN_OFFSET 0x1000
+#define TCAN4X5X_MAX_REGISTER 0x8fff
+
+#define TCAN4X5X_CLEAR_ALL_INT 0xffffffff
+#define TCAN4X5X_SET_ALL_INT 0xffffffff
+
+#define TCAN4X5X_WRITE_CMD (0x61 << 24)
+#define TCAN4X5X_READ_CMD (0x41 << 24)
+
+#define TCAN4X5X_MODE_SEL_MASK (BIT(7) | BIT(6))
+#define TCAN4X5X_MODE_SLEEP 0x00
+#define TCAN4X5X_MODE_STANDBY BIT(6)
+#define TCAN4X5X_MODE_NORMAL BIT(7)
+
+#define TCAN4X5X_SW_RESET BIT(2)
+
+#define TCAN4X5X_MCAN_CONFIGURED BIT(5)
+#define TCAN4X5X_WATCHDOG_EN BIT(3)
+#define TCAN4X5X_WD_60_MS_TIMER 0
+#define TCAN4X5X_WD_600_MS_TIMER BIT(28)
+#define TCAN4X5X_WD_3_S_TIMER BIT(29)
+#define TCAN4X5X_WD_6_S_TIMER (BIT(28) | BIT(29))
+
+struct tcan4x5x_priv {
+ struct regmap *regmap;
+ struct spi_device *spi;
+ struct mutex tcan4x5x_lock; /* SPI device lock */
+
+ struct m_can_classdev *mcan_dev;
+
+ struct gpio_desc *reset_gpio;
+ struct gpio_desc *interrupt_gpio;
+ struct gpio_desc *device_wake_gpio;
+ struct gpio_desc *device_state_gpio;
+ struct regulator *power;
+
+ /* Register based ip */
+ int mram_start;
+ int reg_offset;
+};
+
+static struct can_bittiming_const tcan4x5x_bittiming_const = {
+ .name = DEVICE_NAME,
+ .tseg1_min = 2,
+ .tseg1_max = 31,
+ .tseg2_min = 2,
+ .tseg2_max = 16,
+ .sjw_max = 16,
+ .brp_min = 1,
+ .brp_max = 32,
+ .brp_inc = 1,
+};
+
+static struct can_bittiming_const tcan4x5x_data_bittiming_const = {
+ .name = DEVICE_NAME,
+ .tseg1_min = 1,
+ .tseg1_max = 32,
+ .tseg2_min = 1,
+ .tseg2_max = 16,
+ .sjw_max = 16,
+ .brp_min = 1,
+ .brp_max = 32,
+ .brp_inc = 1,
+};
+
+static void tcan4x5x_check_wake(struct tcan4x5x_priv *priv)
+{
+ int wake_state = 0;
+
+ if (priv->device_state_gpio)
+ wake_state = gpiod_get_value(priv->device_state_gpio);
+
+ if (priv->device_wake_gpio && wake_state) {
+ gpiod_set_value(priv->device_wake_gpio, 1);
+ udelay(100);
+ gpiod_set_value(priv->device_wake_gpio, 0);
+ udelay(100);
+ gpiod_set_value(priv->device_wake_gpio, 1);
+ }
+}
+
+static int regmap_spi_gather_write(void *context, const void *reg,
+ size_t reg_len, const void *val,
+ size_t val_len)
+{
+ struct device *dev = context;
+ struct spi_device *spi = to_spi_device(dev);
+ struct spi_message m;
+ u32 addr;
+ struct spi_transfer t[2] = {{ .tx_buf = &addr, .len = reg_len, .cs_change = 0,},
+ { .tx_buf = val, .len = val_len, },};
+
+ addr = TCAN4X5X_WRITE_CMD | (*((u16 *)reg) << 8) | val_len >> 3;
+
+ spi_message_init(&m);
+ spi_message_add_tail(&t[0], &m);
+ spi_message_add_tail(&t[1], &m);
+
+ return spi_sync(spi, &m);
+}
+
+static int tcan4x5x_regmap_write(void *context, const void *data, size_t count)
+{
+ u16 *reg = (u16 *)(data);
+ const u32 *val = data + 4;
+
+ return regmap_spi_gather_write(context, reg, 4, val, count);
+}
+
+static int regmap_spi_async_write(void *context,
+ const void *reg, size_t reg_len,
+ const void *val, size_t val_len,
+ struct regmap_async *a)
+{
+ return -ENOTSUPP;
+}
+
+static struct regmap_async *regmap_spi_async_alloc(void)
+{
+ return NULL;
+}
+
+static int tcan4x5x_regmap_read(void *context,
+ const void *reg, size_t reg_size,
+ void *val, size_t val_size)
+{
+ struct device *dev = context;
+ struct spi_device *spi = to_spi_device(dev);
+
+ u32 addr = TCAN4X5X_READ_CMD | (*((u16 *)reg) << 8) | val_size >> 2;
+
+ return spi_write_then_read(spi, &addr, reg_size, (u32 *)val, val_size);
+}
+
+static struct regmap_bus tcan4x5x_bus = {
+ .write = tcan4x5x_regmap_write,
+ .gather_write = regmap_spi_gather_write,
+ .async_write = regmap_spi_async_write,
+ .async_alloc = regmap_spi_async_alloc,
+ .read = tcan4x5x_regmap_read,
+ .read_flag_mask = 0x00,
+ .reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
+ .val_format_endian_default = REGMAP_ENDIAN_NATIVE,
+};
+
+static u32 tcan4x5x_read_reg(struct m_can_classdev *m_can_class, int reg)
+{
+ struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)m_can_class->device_data;
+ u32 val;
+
+ tcan4x5x_check_wake(priv);
+
+ regmap_read(priv->regmap, priv->reg_offset + reg, &val);
+
+ return val;
+}
+
+static u32 tcan4x5x_read_fifo(struct m_can_classdev *m_can_class,
+ int addr_offset)
+{
+ struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)m_can_class->device_data;
+ u32 val;
+
+ tcan4x5x_check_wake(priv);
+
+ regmap_read(priv->regmap, priv->mram_start + addr_offset, &val);
+
+ return val;
+}
+
+static int tcan4x5x_write_reg(struct m_can_classdev *m_can_class,
+ int reg, int val)
+{
+ struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)m_can_class->device_data;
+
+ tcan4x5x_check_wake(priv);
+
+ return regmap_write(priv->regmap, priv->reg_offset + reg, val);
+}
+
+static int tcan4x5x_write_fifo(struct m_can_classdev *m_can_class,
+ int addr_offset, int val)
+{
+ struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)m_can_class->device_data;
+
+ tcan4x5x_check_wake(priv);
+
+ return regmap_write(priv->regmap, priv->mram_start + addr_offset, val);
+}
+
+static int tcan4x5x_power_enable(struct regulator *reg, int enable)
+{
+ if (IS_ERR_OR_NULL(reg))
+ return 0;
+
+ if (enable)
+ return regulator_enable(reg);
+ else
+ return regulator_disable(reg);
+}
+
+static int tcan4x5x_write_tcan_reg(struct m_can_classdev *m_can_class,
+ int reg, int val)
+{
+ struct tcan4x5x_priv *priv = (struct tcan4x5x_priv *)m_can_class->device_data;
+
+ tcan4x5x_check_wake(priv);
+
+ return regmap_write(priv->regmap, reg, val);
+}
+
+static int tcan4x5x_clear_interrupts(struct m_can_classdev *class_dev)
+{
+ struct tcan4x5x_priv *tcan4x5x = (struct tcan4x5x_priv *)class_dev->device_data;
+ int ret;
+
+ tcan4x5x_check_wake(tcan4x5x);
+
+ ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_STATUS,
+ TCAN4X5X_CLEAR_ALL_INT);
+ if (ret)
+ return -EIO;
+
+ ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_MCAN_INT_REG,
+ TCAN4X5X_ENABLE_MCAN_INT);
+ if (ret)
+ return -EIO;
+
+ ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_INT_FLAGS,
+ TCAN4X5X_CLEAR_ALL_INT);
+ if (ret)
+ return -EIO;
+
+
+ ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_ERROR_STATUS,
+ TCAN4X5X_CLEAR_ALL_INT);
+ if (ret)
+ return -EIO;
+
+ return ret;
+}
+
+static int tcan4x5x_init(struct m_can_classdev *class_dev)
+{
+ struct tcan4x5x_priv *tcan4x5x = (struct tcan4x5x_priv *)class_dev->device_data;
+ int ret;
+
+ tcan4x5x_check_wake(tcan4x5x);
+
+ ret = tcan4x5x_clear_interrupts(class_dev);
+ if (ret)
+ return ret;
+
+ ret = tcan4x5x_write_tcan_reg(class_dev, TCAN4X5X_INT_EN,
+ TCAN4X5X_ENABLE_TCAN_INT);
+ if (ret)
+ return -EIO;
+
+ ret = regmap_update_bits(tcan4x5x->regmap, TCAN4X5X_CONFIG,
+ TCAN4X5X_MODE_SEL_MASK, TCAN4X5X_MODE_NORMAL);
+ if (ret)
+ return -EIO;
+
+ /* Zero out the MCAN buffers */
+ m_can_init_ram(class_dev);
+
+ return ret;
+}
+
+static int tcan4x5x_parse_config(struct m_can_classdev *class_dev)
+{
+ struct tcan4x5x_priv *tcan4x5x = (struct tcan4x5x_priv *)class_dev->device_data;
+
+ tcan4x5x->reset_gpio = devm_gpiod_get_optional(class_dev->dev,
+ "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(tcan4x5x->reset_gpio))
+ tcan4x5x->reset_gpio = NULL;
+
+ tcan4x5x->device_wake_gpio = devm_gpiod_get_optional(class_dev->dev,
+ "device-wake",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(tcan4x5x->device_wake_gpio))
+ tcan4x5x->device_wake_gpio = NULL;
+
+ tcan4x5x->device_state_gpio = devm_gpiod_get_optional(class_dev->dev,
+ "device-state",
+ GPIOD_IN);
+ if (IS_ERR(tcan4x5x->device_state_gpio))
+ tcan4x5x->device_state_gpio = NULL;
+
+ tcan4x5x->interrupt_gpio = devm_gpiod_get(class_dev->dev,
+ "data-ready", GPIOD_IN);
+ if (IS_ERR(tcan4x5x->interrupt_gpio)) {
+ dev_err(class_dev->dev, "data-ready gpio not defined\n");
+ return -EINVAL;
+ }
+
+ class_dev->net->irq = gpiod_to_irq(tcan4x5x->interrupt_gpio);
+
+ tcan4x5x->power = devm_regulator_get_optional(class_dev->dev,
+ "vsup");
+ if (PTR_ERR(tcan4x5x->power) == -EPROBE_DEFER)
+ return -EPROBE_DEFER;
+
+ return 0;
+}
+
+static const struct regmap_config tcan4x5x_regmap = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .cache_type = REGCACHE_NONE,
+ .max_register = TCAN4X5X_MAX_REGISTER,
+};
+
+static int tcan4x5x_can_probe(struct spi_device *spi)
+{
+ struct tcan4x5x_priv *priv;
+ struct m_can_classdev *mcan_class;
+ int freq, ret;
+
+ mcan_class = m_can_core_allocate_dev(&spi->dev);
+ priv = devm_kzalloc(&spi->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ mcan_class->device_data = priv;
+
+ m_can_core_get_clocks(mcan_class);
+ if (IS_ERR(mcan_class->cclk)) {
+ dev_err(&spi->dev, "no CAN clock source defined\n");
+ freq = TCAN4X5X_EXT_CLK_DEF;
+ } else {
+ freq = clk_get_rate(mcan_class->cclk);
+ }
+
+ /* Sanity check */
+ if (freq < 20000000 || freq > TCAN4X5X_EXT_CLK_DEF)
+ return -ERANGE;
+
+ priv->reg_offset = TCAN4X5X_MCAN_OFFSET;
+ priv->mram_start = TCAN4X5X_MRAM_START;
+ priv->spi = spi;
+ priv->mcan_dev = mcan_class;
+
+ mcan_class->pm_clock_support = 0;
+ mcan_class->can.clock.freq = freq;
+ mcan_class->dev = &spi->dev;
+
+ mcan_class->device_init = &tcan4x5x_init;
+ mcan_class->read_reg = &tcan4x5x_read_reg;
+ mcan_class->write_reg = &tcan4x5x_write_reg;
+ mcan_class->write_fifo = &tcan4x5x_write_fifo;
+ mcan_class->read_fifo = &tcan4x5x_read_fifo;
+ mcan_class->clr_dev_interrupts = &tcan4x5x_clear_interrupts;
+ mcan_class->is_peripherial = true;
+
+ mcan_class->bit_timing = &tcan4x5x_bittiming_const;
+ mcan_class->data_timing = &tcan4x5x_data_bittiming_const;
+
+ spi_set_drvdata(spi, priv);
+
+ ret = tcan4x5x_parse_config(mcan_class);
+ if (ret)
+ goto out_clk;
+
+ /* Configure the SPI bus */
+ spi->bits_per_word = 32;
+ ret = spi_setup(spi);
+ if (ret)
+ goto out_clk;
+
+ priv->regmap = devm_regmap_init(&spi->dev, &tcan4x5x_bus,
+ &spi->dev, &tcan4x5x_regmap);
+
+ mutex_init(&priv->tcan4x5x_lock);
+
+ tcan4x5x_power_enable(priv->power, 1);
+
+ ret = m_can_core_register(mcan_class);
+ if (ret)
+ goto reg_err;
+
+ netdev_info(mcan_class->net, "TCAN4X5X successfully initialized.\n");
+ return 0;
+
+reg_err:
+ tcan4x5x_power_enable(priv->power, 0);
+out_clk:
+ if (!IS_ERR(mcan_class->cclk)) {
+ clk_disable_unprepare(mcan_class->cclk);
+ clk_disable_unprepare(mcan_class->hclk);
+ }
+
+ dev_err(&spi->dev, "Probe failed, err=%d\n", -ret);
+ return ret;
+}
+
+static int tcan4x5x_can_remove(struct spi_device *spi)
+{
+ struct tcan4x5x_priv *priv = spi_get_drvdata(spi);
+
+ tcan4x5x_power_enable(priv->power, 0);
+
+ m_can_core_unregister(priv->mcan_dev);
+
+ return 0;
+}
+
+static const struct of_device_id tcan4x5x_of_match[] = {
+ { .compatible = "ti,tcan4x5x", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, tcan4x5x_of_match);
+
+static const struct spi_device_id tcan4x5x_id_table[] = {
+ {
+ .name = "tcan4x5x",
+ .driver_data = 0,
+ },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, tcan4x5x_id_table);
+
+static struct spi_driver tcan4x5x_can_driver = {
+ .driver = {
+ .name = DEVICE_NAME,
+ .of_match_table = tcan4x5x_of_match,
+ .pm = NULL,
+ },
+ .id_table = tcan4x5x_id_table,
+ .probe = tcan4x5x_can_probe,
+ .remove = tcan4x5x_can_remove,
+};
+module_spi_driver(tcan4x5x_can_driver);
+
+MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
+MODULE_DESCRIPTION("Texas Instruments TCAN4x5x CAN driver");
+MODULE_LICENSE("GPL v2");
--
2.20.1.98.gecbdaf0899