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

Wolfgang Grandegger
2019-01-22T10:03:54Z

Hello,

Am 17.01.19 um 21:06 schrieb Dan Murphy:
> 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)

These bits are already defined in the common header file.

> +#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");

Curious to hear about the performance of M_CAN connected via SPI. Does
it miss or drop messages?

Thanks for your patience,

Wolfgang.