From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
Add GPIOLIB support to mcp25xxfd.
Signed-off-by: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
Tested-by: Gerhard Bertelsmann <info@xxxxxxxxxxxxxxxxxxxxxx>
---
Changelog:
V1 -> V2: implemented support as per feedback
V2 -> V3: moved dt-binding changes to patch 1
---
drivers/net/can/spi/mcp25xxfd.c | 185 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 185 insertions(+)
diff --git a/drivers/net/can/spi/mcp25xxfd.c b/drivers/net/can/spi/mcp25xxfd.c
index 49a454da2196..10b60baddfb2 100644
--- a/drivers/net/can/spi/mcp25xxfd.c
+++ b/drivers/net/can/spi/mcp25xxfd.c
@@ -20,6 +20,7 @@
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/freezer.h>
+#include <linux/gpio/driver.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/jiffies.h>
@@ -806,9 +807,15 @@ struct mcp25xxfd_priv {
struct mutex clk_user_lock; /* lock for enabling/disabling the clock */
int clk_user_mask;
#define MCP25XXFD_CLK_USER_CAN BIT(0)
+#define MCP25XXFD_CLK_USER_GPIO0 BIT(1)
+#define MCP25XXFD_CLK_USER_GPIO1 BIT(2)
struct dentry *debugfs_dir;
+#ifdef CONFIG_GPIOLIB
+ struct gpio_chip gpio;
+#endif
+
/* the actual model of the mcp25xxfd */
enum mcp25xxfd_model model;
@@ -1494,6 +1501,179 @@ static int mcp25xxfd_stop_clock(struct spi_device *spi, int requestor_mask)
return 0;
}
+/* mcp25xxfd GPIO helper functions */
+#ifdef CONFIG_GPIOLIB
+
+enum mcp25xxfd_gpio_pins {
+ MCP25XXFD_GPIO_GPIO0 = 0,
+ MCP25XXFD_GPIO_GPIO1 = 1,
+};
+
+static int mcp25xxfd_gpio_request(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct mcp25xxfd_priv *priv = gpiochip_get_data(chip);
+ int clock_requestor = offset ?
+ MCP25XXFD_CLK_USER_GPIO1 : MCP25XXFD_CLK_USER_GPIO0;
+
+ /* only handle gpio 0/1 */
+ if (offset > 1)
+ return -EINVAL;
+
+ mcp25xxfd_start_clock(priv->spi, clock_requestor);
+
+ return 0;
+}
+
+static void mcp25xxfd_gpio_free(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct mcp25xxfd_priv *priv = gpiochip_get_data(chip);
+ int clock_requestor = offset ?
+ MCP25XXFD_CLK_USER_GPIO1 : MCP25XXFD_CLK_USER_GPIO0;
+
+ /* only handle gpio 0/1 */
+ if (offset > 1)
+ return;
+
+ mcp25xxfd_stop_clock(priv->spi, clock_requestor);
+}
+
+static int mcp25xxfd_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct mcp25xxfd_priv *priv = gpiochip_get_data(chip);
+ u32 mask = (offset) ? MCP25XXFD_IOCON_GPIO1 : MCP25XXFD_IOCON_GPIO0;
+ int ret;
+
+ /* only handle gpio 0/1 */
+ if (offset > 1)
+ return -EINVAL;
+
+ /* read the relevant gpio Latch */
+ ret = mcp25xxfd_cmd_read_mask(priv->spi, MCP25XXFD_IOCON,
+ &priv->regs.iocon, mask,
+ priv->spi_setup_speed_hz);
+ if (ret)
+ return ret;
+
+ /* return the match */
+ return priv->regs.iocon & mask;
+}
+
+static void mcp25xxfd_gpio_set(struct gpio_chip *chip, unsigned int offset,
+ int value)
+{
+ struct mcp25xxfd_priv *priv = gpiochip_get_data(chip);
+ u32 mask = (offset) ? MCP25XXFD_IOCON_LAT1 : MCP25XXFD_IOCON_LAT0;
+
+ /* only handle gpio 0/1 */
+ if (offset > 1)
+ return;
+
+ /* update in memory representation with the corresponding value */
+ if (value)
+ priv->regs.iocon |= mask;
+ else
+ priv->regs.iocon &= ~mask;
+
+ mcp25xxfd_cmd_write_mask(priv->spi, MCP25XXFD_IOCON,
+ priv->regs.iocon, mask,
+ priv->spi_setup_speed_hz);
+}
+
+static int mcp25xxfd_gpio_direction_input(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct mcp25xxfd_priv *priv = gpiochip_get_data(chip);
+ u32 mask_tri = (offset) ?
+ MCP25XXFD_IOCON_TRIS1 : MCP25XXFD_IOCON_TRIS0;
+ u32 mask_stby = (offset) ?
+ 0 : MCP25XXFD_IOCON_XSTBYEN;
+ u32 mask_pm = (offset) ?
+ MCP25XXFD_IOCON_PM1 : MCP25XXFD_IOCON_PM0;
+
+ /* only handle gpio 0/1 */
+ if (offset > 1)
+ return -EINVAL;
+
+ /* set the mask */
+ priv->regs.iocon |= mask_tri | mask_pm;
+
+ /* clear stby */
+ priv->regs.iocon &= ~mask_stby;
+
+ return mcp25xxfd_cmd_write_mask(priv->spi, MCP25XXFD_IOCON,
+ priv->regs.iocon,
+ mask_tri | mask_stby | mask_pm,
+ priv->spi_setup_speed_hz);
+}
+
+static int mcp25xxfd_gpio_direction_output(struct gpio_chip *chip,
+ unsigned int offset, int value)
+{
+ struct mcp25xxfd_priv *priv = gpiochip_get_data(chip);
+ u32 mask_tri = (offset) ?
+ MCP25XXFD_IOCON_TRIS1 : MCP25XXFD_IOCON_TRIS0;
+ u32 mask_lat = (offset) ?
+ MCP25XXFD_IOCON_LAT1 : MCP25XXFD_IOCON_LAT0;
+ u32 mask_pm = (offset) ?
+ MCP25XXFD_IOCON_PM1 : MCP25XXFD_IOCON_PM0;
+ u32 mask_stby = (offset) ?
+ 0 : MCP25XXFD_IOCON_XSTBYEN;
+
+ /* only handle gpio 0/1 */
+ if (offset > 1)
+ return -EINVAL;
+
+ /* clear the tristate bit and also clear stby */
+ priv->regs.iocon &= ~(mask_tri | mask_stby);
+
+ /* set GPIO mode */
+ priv->regs.iocon |= mask_pm;
+
+ /* set the value */
+ if (value)
+ priv->regs.iocon |= mask_lat;
+ else
+ priv->regs.iocon &= ~mask_lat;
+
+ return mcp25xxfd_cmd_write_mask(priv->spi, MCP25XXFD_IOCON,
+ priv->regs.iocon,
+ mask_tri | mask_lat |
+ mask_pm | mask_stby,
+ priv->spi_setup_speed_hz);
+}
+
+static int mcp25xxfd_gpio_setup(struct spi_device *spi)
+{
+ struct mcp25xxfd_priv *priv = spi_get_drvdata(spi);
+
+ /* gpiochip only handles GPIO0 and GPIO1 */
+ priv->gpio.owner = THIS_MODULE;
+ priv->gpio.parent = &spi->dev;
+ priv->gpio.label = dev_name(&spi->dev);
+ priv->gpio.direction_input = mcp25xxfd_gpio_direction_input;
+ priv->gpio.get = mcp25xxfd_gpio_get;
+ priv->gpio.direction_output = mcp25xxfd_gpio_direction_output;
+ priv->gpio.set = mcp25xxfd_gpio_set;
+ priv->gpio.request = mcp25xxfd_gpio_request;
+ priv->gpio.free = mcp25xxfd_gpio_free;
+ priv->gpio.base = -1;
+ priv->gpio.ngpio = 2;
+ priv->gpio.can_sleep = 1;
+
+ return devm_gpiochip_add_data(&spi->dev, &priv->gpio, priv);
+}
+
+#else
+
+static int mcp25xxfd_gpio_setup(struct spi_device *spi)
+{
+ return 0;
+}
+
+#endif
+
/* ideally these would be defined in uapi/linux/can.h */
#define CAN_EFF_SID_SHIFT (CAN_EFF_ID_BITS - CAN_SFF_ID_BITS)
#define CAN_EFF_SID_BITS CAN_SFF_ID_BITS
@@ -4104,6 +4284,11 @@ static int mcp25xxfd_can_probe(struct spi_device *spi)
if (ret)
goto out_free;
+ /* Setup GPIO controller */
+ ret = mcp25xxfd_gpio_setup(spi);
+ if (ret)
+ goto out_clk;
+
/* all by default as push/pull */
priv->config.gpio_opendrain = false;
--
2.11.0
--
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