[PATCH 3/4] can: mcp251xfd: add gpio functionality

Gregor Herburger
2024-04-17T13:44:24Z

The mcp251xfd devices allow two pins to be configured as gpio. Add this
functionality to driver.

Signed-off-by: Gregor Herburger <gregor.herburger@ew.tq-group.com>
---
drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 138 ++++++++++++++++++++++-
drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c | 21 +++-
drivers/net/can/spi/mcp251xfd/mcp251xfd.h | 4 +
3 files changed, 159 insertions(+), 4 deletions(-)

diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index eb699288c076..5ba9fd0af4b6 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -16,6 +16,7 @@
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/device.h>
+#include <linux/gpio/driver.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
@@ -366,6 +367,8 @@ static int mcp251xfd_chip_wake(const struct mcp251xfd_priv *priv)

static inline int mcp251xfd_chip_sleep(const struct mcp251xfd_priv *priv)
{
+ int ret;
+
if (priv->pll_enable) {
u32 osc;
int err;
@@ -381,7 +384,12 @@ static inline int mcp251xfd_chip_sleep(const struct mcp251xfd_priv *priv)
priv->spi->max_speed_hz = priv->spi_max_speed_hz_slow;
}

- return mcp251xfd_chip_set_mode(priv, MCP251XFD_REG_CON_MODE_SLEEP);
+ ret = mcp251xfd_chip_set_mode(priv, MCP251XFD_REG_CON_MODE_SLEEP);
+
+ regcache_cache_only(priv->map_reg, true);
+ regcache_mark_dirty(priv->map_reg);
+
+ return ret;
}

static int mcp251xfd_chip_softreset_do(const struct mcp251xfd_priv *priv)
@@ -389,6 +397,8 @@ static int mcp251xfd_chip_softreset_do(const struct mcp251xfd_priv *priv)
const __be16 cmd = mcp251xfd_cmd_reset();
int err;

+ regcache_cache_only(priv->map_reg, false);
+
/* The Set Mode and SPI Reset command only works if the
* controller is not in Sleep Mode.
*/
@@ -401,7 +411,12 @@ static int mcp251xfd_chip_softreset_do(const struct mcp251xfd_priv *priv)
return err;

/* spi_write_then_read() works with non DMA-safe buffers */
- return spi_write_then_read(priv->spi, &cmd, sizeof(cmd), NULL, 0);
+ err = spi_write_then_read(priv->spi, &cmd, sizeof(cmd), NULL, 0);
+ if (err)
+ return err;
+
+ /* After reset restore cached register values to hardware */
+ return regcache_sync(priv->map_reg);
}

static int mcp251xfd_chip_softreset_check(const struct mcp251xfd_priv *priv)
@@ -1772,6 +1787,119 @@ static int mcp251xfd_register_check_rx_int(struct mcp251xfd_priv *priv)
return 0;
}

+static const char * const mcp251xfd_gpio_names[] = {"GPIO0", "GPIO1"};
+
+static int mcp251xfd_gpio_request(struct gpio_chip *chip, unsigned int offset)
+{
+ struct mcp251xfd_priv *priv = gpiochip_get_data(chip);
+ u32 pin_mask = MCP251XFD_REG_IOCON_PM0 << offset;
+
+ return regmap_update_bits(priv->map_reg, MCP251XFD_REG_IOCON,
+ pin_mask, pin_mask);
+}
+
+static int mcp251xfd_gpio_get_direction(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct mcp251xfd_priv *priv = gpiochip_get_data(chip);
+ u32 mask = MCP251XFD_REG_IOCON_TRIS0 << offset;
+ u32 val;
+
+ regmap_read(priv->map_reg, MCP251XFD_REG_IOCON, &val);
+
+ if (mask & val)
+ return GPIO_LINE_DIRECTION_IN;
+
+ return GPIO_LINE_DIRECTION_OUT;
+}
+
+static int mcp251xfd_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct mcp251xfd_priv *priv = gpiochip_get_data(chip);
+ u32 mask = MCP251XFD_REG_IOCON_GPIO0 << offset;
+ u32 val;
+
+ regcache_drop_region(priv->map_reg, MCP251XFD_REG_IOCON, MCP251XFD_REG_IOCON);
+ regmap_read(priv->map_reg, MCP251XFD_REG_IOCON, &val);
+
+ return !!(mask & val);
+}
+
+static int mcp251xfd_gpio_direction_output(struct gpio_chip *chip,
+ unsigned int offset, int value)
+{
+ struct mcp251xfd_priv *priv = gpiochip_get_data(chip);
+ u32 dir_mask = MCP251XFD_REG_IOCON_TRIS0 << offset;
+ u32 val_mask = MCP251XFD_REG_IOCON_LAT0 << offset;
+ u32 val;
+
+ if (value)
+ val = val_mask;
+ else
+ val = 0;
+
+ return regmap_update_bits(priv->map_reg, MCP251XFD_REG_IOCON,
+ dir_mask | val_mask, val);
+}
+
+static int mcp251xfd_gpio_direction_input(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct mcp251xfd_priv *priv = gpiochip_get_data(chip);
+ u32 dir_mask = MCP251XFD_REG_IOCON_TRIS0 << offset;
+
+ return regmap_update_bits(priv->map_reg, MCP251XFD_REG_IOCON,
+ dir_mask, dir_mask);
+}
+
+static void mcp251xfd_gpio_set(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+ struct mcp251xfd_priv *priv = gpiochip_get_data(chip);
+ u32 val_mask = MCP251XFD_REG_IOCON_LAT0 << offset;
+ u32 val;
+ int ret;
+
+ if (value)
+ val = val_mask;
+ else
+ val = 0;
+
+ ret = regmap_update_bits(priv->map_reg, MCP251XFD_REG_IOCON,
+ val_mask, val);
+ if (ret)
+ dev_warn(&priv->spi->dev,
+ "Failed to set GPIO %u: %d\n", offset, ret);
+}
+
+static int mcp251fdx_gpio_setup(struct mcp251xfd_priv *priv)
+{
+ struct gpio_chip *gc = &priv->gc;
+
+ if (!device_property_present(&priv->spi->dev, "gpio-controller"))
+ return 0;
+
+ if (priv->rx_int)
+ return dev_err_probe(&priv->spi->dev, -EINVAL,
+ "Can't configure gpio-controller with RX-INT!\n");
+
+ gc->label = dev_name(&priv->spi->dev);
+ gc->parent = &priv->spi->dev;
+ gc->owner = THIS_MODULE;
+ gc->request = mcp251xfd_gpio_request;
+ gc->get_direction = mcp251xfd_gpio_get_direction;
+ gc->direction_output = mcp251xfd_gpio_direction_output;
+ gc->direction_input = mcp251xfd_gpio_direction_input;
+ gc->get = mcp251xfd_gpio_get;
+ gc->set = mcp251xfd_gpio_set;
+ gc->base = -1;
+ gc->can_sleep = true;
+ gc->ngpio = ARRAY_SIZE(mcp251xfd_gpio_names);
+ gc->names = mcp251xfd_gpio_names;
+
+ return devm_gpiochip_add_data(&priv->spi->dev, gc, priv);
+}
+
static int
mcp251xfd_register_get_dev_id(const struct mcp251xfd_priv *priv, u32 *dev_id,
u32 *effective_speed_hz_slow,
@@ -2142,6 +2270,12 @@ static int mcp251xfd_probe(struct spi_device *spi)
if (err)
goto out_free_candev;

+ err = mcp251fdx_gpio_setup(priv);
+ if (err) {
+ dev_err_probe(&spi->dev, err, "Failed to register gpio-controller.\n");
+ goto out_free_candev;
+ }
+
err = mcp251xfd_register(priv);
if (err) {
dev_err_probe(&spi->dev, err, "Failed to detect %s.\n",
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
index ab4e372baffb..868c424f22a4 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-regmap.c
@@ -447,6 +447,21 @@ static const struct regmap_access_table mcp251xfd_reg_table = {
.n_yes_ranges = ARRAY_SIZE(mcp251xfd_reg_table_yes_range),
};

+static bool mcp251xfd_volatile_reg(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case MCP251XFD_REG_ECCCON:
+ case MCP251XFD_REG_DEVID:
+ case MCP251XFD_REG_NBTCFG:
+ case MCP251XFD_REG_DBTCFG:
+ case MCP251XFD_REG_TDC:
+ case MCP251XFD_REG_TSCON:
+ case MCP251XFD_REG_IOCON:
+ return false;
+ }
+ return true;
+}
+
static const struct regmap_config mcp251xfd_regmap_nocrc = {
.name = "nocrc",
.reg_bits = 16,
@@ -456,7 +471,8 @@ static const struct regmap_config mcp251xfd_regmap_nocrc = {
.max_register = 0xffc,
.wr_table = &mcp251xfd_reg_table,
.rd_table = &mcp251xfd_reg_table,
- .cache_type = REGCACHE_NONE,
+ .cache_type = REGCACHE_MAPLE,
+ .volatile_reg = mcp251xfd_volatile_reg,
.read_flag_mask = (__force unsigned long)
cpu_to_be16(MCP251XFD_SPI_INSTRUCTION_READ),
.write_flag_mask = (__force unsigned long)
@@ -483,7 +499,8 @@ static const struct regmap_config mcp251xfd_regmap_crc = {
.max_register = 0xffc,
.wr_table = &mcp251xfd_reg_table,
.rd_table = &mcp251xfd_reg_table,
- .cache_type = REGCACHE_NONE,
+ .cache_type = REGCACHE_MAPLE,
+ .volatile_reg = mcp251xfd_volatile_reg,
};

static const struct regmap_bus mcp251xfd_bus_crc = {
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
index 24510b3b8020..e2ab486862d8 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
@@ -14,6 +14,7 @@
#include <linux/can/core.h>
#include <linux/can/dev.h>
#include <linux/can/rx-offload.h>
+#include <linux/gpio/driver.h>
#include <linux/gpio/consumer.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
@@ -660,6 +661,9 @@ struct mcp251xfd_priv {

struct mcp251xfd_devtype_data devtype_data;
struct can_berr_counter bec;
+#ifdef CONFIG_GPIOLIB
+ struct gpio_chip gc;
+#endif
};

#define MCP251XFD_IS(_model) \

--
2.34.1