[PATCH v2 5/6] can: mcp251xfd: add gpio functionality

From: Gregor Herburger
Date: Mon May 06 2024 - 02:01:55 EST


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

Signed-off-by: Gregor Herburger <gregor.herburger@xxxxxxxxxxxxxxx>
---
drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c | 173 +++++++++++++++++++++++++
drivers/net/can/spi/mcp251xfd/mcp251xfd.h | 6 +
2 files changed, 179 insertions(+)

diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index 4739ad80ef2a..de301f3a2f4e 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>
@@ -1768,6 +1769,172 @@ static int mcp251xfd_register_check_rx_int(struct mcp251xfd_priv *priv)
return 0;
}

+#ifdef CONFIG_GPIOLIB
+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;
+ int ret;
+
+ if (priv->rx_int && offset == 1) {
+ netdev_err(priv->ndev, "Can't use GPIO 1 with RX-INT!\n");
+ return -EINVAL;
+ }
+
+ ret = pm_runtime_resume_and_get(priv->ndev->dev.parent);
+ if (ret)
+ return ret;
+
+ return regmap_update_bits(priv->map_reg, MCP251XFD_REG_IOCON,
+ pin_mask, pin_mask);
+}
+
+static void mcp251xfd_gpio_free(struct gpio_chip *chip, unsigned int offset)
+{
+ struct mcp251xfd_priv *priv = gpiochip_get_data(chip);
+
+ pm_runtime_put(priv->ndev->dev.parent);
+}
+
+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;
+
+ regmap_read(priv->map_reg, MCP251XFD_REG_IOCON, &val);
+
+ return !!(mask & val);
+}
+
+static int mcp251xfd_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
+ unsigned long *bit)
+{
+ struct mcp251xfd_priv *priv = gpiochip_get_data(chip);
+ u32 val;
+ int ret;
+
+ ret = regmap_read(priv->map_reg, MCP251XFD_REG_IOCON, &val);
+ if (ret)
+ return ret;
+
+ *bit = FIELD_GET(MCP251XFD_REG_IOCON_GPIO_MASK, val) & *mask;
+
+ return 0;
+}
+
+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 void mcp251xfd_gpio_set_multiple(struct gpio_chip *chip, unsigned long *mask,
+ unsigned long *bits)
+{
+ struct mcp251xfd_priv *priv = gpiochip_get_data(chip);
+ u32 val;
+ int ret;
+
+ val = FIELD_PREP(MCP251XFD_REG_IOCON_LAT_MASK, *bits);
+
+ ret = regmap_update_bits(priv->map_reg, MCP251XFD_REG_IOCON,
+ MCP251XFD_REG_IOCON_LAT_MASK, val);
+ if (ret)
+ dev_warn(&priv->spi->dev, "Failed to set GPIOs %d\n", 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;
+
+ gc->label = dev_name(&priv->spi->dev);
+ gc->parent = &priv->spi->dev;
+ gc->owner = THIS_MODULE;
+ gc->request = mcp251xfd_gpio_request;
+ gc->free = mcp251xfd_gpio_free;
+ 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->get_multiple = mcp251xfd_gpio_get_multiple;
+ gc->set = mcp251xfd_gpio_set;
+ gc->set_multiple = mcp251xfd_gpio_set_multiple;
+ 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);
+}
+#else
+static inline int mcp251fdx_gpio_setup(struct mcp251xfd_priv *priv)
+{
+ return 0;
+}
+#endif
+
static int
mcp251xfd_register_get_dev_id(const struct mcp251xfd_priv *priv, u32 *dev_id,
u32 *effective_speed_hz_slow,
@@ -2141,6 +2308,12 @@ 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.h b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
index 75d5a8a25415..dc34da848f00 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h
@@ -15,6 +15,7 @@
#include <linux/can/dev.h>
#include <linux/can/rx-offload.h>
#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/regmap.h>
@@ -337,8 +338,10 @@
#define MCP251XFD_REG_IOCON_PM0 BIT(24)
#define MCP251XFD_REG_IOCON_GPIO1 BIT(17)
#define MCP251XFD_REG_IOCON_GPIO0 BIT(16)
+#define MCP251XFD_REG_IOCON_GPIO_MASK GENMASK(17, 16)
#define MCP251XFD_REG_IOCON_LAT1 BIT(9)
#define MCP251XFD_REG_IOCON_LAT0 BIT(8)
+#define MCP251XFD_REG_IOCON_LAT_MASK GENMASK(9, 8)
#define MCP251XFD_REG_IOCON_XSTBYEN BIT(6)
#define MCP251XFD_REG_IOCON_TRIS1 BIT(1)
#define MCP251XFD_REG_IOCON_TRIS0 BIT(0)
@@ -660,6 +663,9 @@ 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