Re: [PATCH v4 5/6] can: mcp251xfd: add gpio functionality
From: Bartosz Golaszewski <hidden>
Date: 2025-09-18 10:46:48
Also in:
linux-can, lkml
On Thu, 18 Sep 2025 08:49:02 +0200, Viken Dadhaniya [off-list ref] said:
quoted hunk ↗ jump to hunk
From: Gregor Herburger <redacted> The mcp251xfd devices allow two pins to be configured as gpio. Add this functionality to driver. Signed-off-by: Gregor Herburger <redacted> Tested-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com> Signed-off-by: Viken Dadhaniya <viken.dadhaniya@oss.qualcomm.com> --- .../net/can/spi/mcp251xfd/mcp251xfd-core.c | 179 ++++++++++++++++++ drivers/net/can/spi/mcp251xfd/mcp251xfd.h | 4 + 2 files changed, 183 insertions(+)diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c index ea41f04ae1a6..8c253091f498 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>@@ -1797,6 +1798,178 @@ static int mcp251xfd_register_check_rx_int(struct mcp251xfd_priv *priv) return 0; } +#ifdef CONFIG_GPIOLIB
Any reason why you don't just depend on GPIOLIB in Kconfig? There's no reason to make it optional if the device always has the GPIO pins.
+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_PM(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_TRIS(offset);
+ u32 val;
+ int ret;
+
+ ret = regmap_read(priv->map_reg, MCP251XFD_REG_IOCON, &val);
+ if (ret)
+ return ret;
+
+ 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_GPIO(offset);
+ u32 val;
+ int ret;
+
+ ret = regmap_read(priv->map_reg, MCP251XFD_REG_IOCON, &val);
+ if (ret)
+ return ret;
+
+ 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_TRIS(offset);
+ u32 val_mask = MCP251XFD_REG_IOCON_LAT(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_TRIS(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)You must be rebased on pre v6.17 code, this will not compile with current mainline.
+{
+ struct mcp251xfd_priv *priv = gpiochip_get_data(chip);
+ u32 val_mask = MCP251XFD_REG_IOCON_LAT(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_err(&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)
+{Same here, the setter callbacks now return int.
quoted hunk ↗ jump to hunk
+ 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_err(&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,@@ -1930,6 +2103,12 @@ static int mcp251xfd_register(struct mcp251xfd_priv *priv) mcp251xfd_ethtool_init(priv); + err = mcp251fdx_gpio_setup(priv); + if (err) { + dev_err_probe(&priv->spi->dev, err, "Failed to register gpio-controller.\n"); + goto out_runtime_disable; + } + err = register_candev(ndev); if (err) goto out_runtime_disable;diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd.h b/drivers/net/can/spi/mcp251xfd/mcp251xfd.h index bd28510a6583..fd9e005708e4 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>@@ -676,6 +677,9 @@ 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
Bart