From: Timo Schlüßler <schluessler@xxxxxxxxx> The mcp251x variants feature 3 general purpose digital inputs and 2 outputs. With this patch they are accessible through the gpio framework. Signed-off-by: Timo Schlüßler <schluessler@xxxxxxxxx> Tested-by: Timo Schlüßler <schluessler@xxxxxxxxx> Link: https://lore.kernel.org/r/20200915223527.1417033-28-mkl@xxxxxxxxxxxxxx Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> --- drivers/net/can/spi/mcp251x.c | 243 ++++++++++++++++++++++++++++++++++ 1 file changed, 243 insertions(+) diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index df3cfe616b2d..4b113f61e39d 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -19,6 +19,7 @@ * Copyright 2007 */ +#include <linux/bitfield.h> #include <linux/can/core.h> #include <linux/can/dev.h> #include <linux/can/led.h> @@ -27,6 +28,8 @@ #include <linux/delay.h> #include <linux/device.h> #include <linux/freezer.h> +#include <linux/gpio.h> +#include <linux/gpio/driver.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/kernel.h> @@ -52,6 +55,30 @@ #define INSTRUCTION_RTS(n) (0x80 | ((n) & 0x07)) /* MPC251x registers */ +#define BFPCTRL 0x0c +# define BFPCTRL_B0BFM BIT(0) +# define BFPCTRL_B1BFM BIT(1) +# define BFPCTRL_BFM(n) (BFPCTRL_B0BFM << (n)) +# define BFPCTRL_BFM_MASK GENMASK(1, 0) +# define BFPCTRL_B0BFE BIT(2) +# define BFPCTRL_B1BFE BIT(3) +# define BFPCTRL_BFE(n) (BFPCTRL_B0BFE << (n)) +# define BFPCTRL_BFE_MASK GENMASK(3, 2) +# define BFPCTRL_B0BFS BIT(4) +# define BFPCTRL_B1BFS BIT(5) +# define BFPCTRL_BFS(n) (BFPCTRL_B0BFS << (n)) +# define BFPCTRL_BFS_MASK GENMASK(5, 4) +#define TXRTSCTRL 0x0d +# define TXRTSCTRL_B0RTSM BIT(0) +# define TXRTSCTRL_B1RTSM BIT(1) +# define TXRTSCTRL_B2RTSM BIT(2) +# define TXRTSCTRL_RTSM(n) (TXRTSCTRL_B0RTSM << (n)) +# define TXRTSCTRL_RTSM_MASK GENMASK(2, 0) +# define TXRTSCTRL_B0RTS BIT(3) +# define TXRTSCTRL_B1RTS BIT(4) +# define TXRTSCTRL_B2RTS BIT(5) +# define TXRTSCTRL_RTS(n) (TXRTSCTRL_B0RTS << (n)) +# define TXRTSCTRL_RTS_MASK GENMASK(5, 3) #define CANSTAT 0x0e #define CANCTRL 0x0f # define CANCTRL_REQOP_MASK 0xe0 @@ -225,6 +252,10 @@ struct mcp251x_priv { struct regulator *power; struct regulator *transceiver; struct clk *clk; +#ifdef CONFIG_GPIOLIB + struct gpio_chip gpio; + u8 reg_bfpctrl; +#endif }; #define MCP251X_IS(_model) \ @@ -345,6 +376,213 @@ static void mcp251x_write_bits(struct spi_device *spi, u8 reg, mcp251x_spi_trans(spi, 4); } +#ifdef CONFIG_GPIOLIB +enum { + MCP251X_GPIO_TX0RTS = 0, /* inputs */ + MCP251X_GPIO_TX1RTS, + MCP251X_GPIO_TX2RTS, + MCP251X_GPIO_RX0BF, /* outputs */ + MCP251X_GPIO_RX1BF, +}; + +#define MCP251X_GPIO_INPUT_MASK \ + GENMASK(MCP251X_GPIO_TX2RTS, MCP251X_GPIO_TX0RTS) +#define MCP251X_GPIO_OUTPUT_MASK \ + GENMASK(MCP251X_GPIO_RX1BF, MCP251X_GPIO_RX0BF) + +static const char * const mcp251x_gpio_names[] = { + [MCP251X_GPIO_TX0RTS] = "TX0RTS", /* inputs */ + [MCP251X_GPIO_TX1RTS] = "TX1RTS", + [MCP251X_GPIO_TX2RTS] = "TX2RTS", + [MCP251X_GPIO_RX0BF] = "RX0BF", /* outputs */ + [MCP251X_GPIO_RX1BF] = "RX1BF", +}; + +static inline bool mcp251x_gpio_is_input(unsigned int offset) +{ + return offset <= MCP251X_GPIO_TX2RTS; +} + +static int mcp251x_gpio_request(struct gpio_chip *chip, + unsigned int offset) +{ + struct mcp251x_priv *priv = gpiochip_get_data(chip); + u8 val; + + /* nothing to be done for inputs */ + if (mcp251x_gpio_is_input(offset)) + return 0; + + val = BFPCTRL_BFE(offset - MCP251X_GPIO_RX0BF); + + mutex_lock(&priv->mcp_lock); + mcp251x_write_bits(priv->spi, BFPCTRL, val, val); + mutex_unlock(&priv->mcp_lock); + + priv->reg_bfpctrl |= val; + + return 0; +} + +static void mcp251x_gpio_free(struct gpio_chip *chip, + unsigned int offset) +{ + struct mcp251x_priv *priv = gpiochip_get_data(chip); + u8 val; + + /* nothing to be done for inputs */ + if (mcp251x_gpio_is_input(offset)) + return; + + val = BFPCTRL_BFE(offset - MCP251X_GPIO_RX0BF); + + mutex_lock(&priv->mcp_lock); + mcp251x_write_bits(priv->spi, BFPCTRL, val, 0); + mutex_unlock(&priv->mcp_lock); + + priv->reg_bfpctrl &= ~val; +} + +static int mcp251x_gpio_get_direction(struct gpio_chip *chip, + unsigned int offset) +{ + if (mcp251x_gpio_is_input(offset)) + return GPIOF_DIR_IN; + + return GPIOF_DIR_OUT; +} + +static int mcp251x_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + struct mcp251x_priv *priv = gpiochip_get_data(chip); + u8 reg, mask, val; + + if (mcp251x_gpio_is_input(offset)) { + reg = TXRTSCTRL; + mask = TXRTSCTRL_RTS(offset); + } else { + reg = BFPCTRL; + mask = BFPCTRL_BFS(offset - MCP251X_GPIO_RX0BF); + } + + mutex_lock(&priv->mcp_lock); + val = mcp251x_read_reg(priv->spi, reg); + mutex_unlock(&priv->mcp_lock); + + return !!(val & mask); +} + +static int mcp251x_gpio_get_multiple(struct gpio_chip *chip, + unsigned long *maskp, unsigned long *bitsp) +{ + struct mcp251x_priv *priv = gpiochip_get_data(chip); + unsigned long bits = 0; + u8 val; + + mutex_lock(&priv->mcp_lock); + if (maskp[0] & MCP251X_GPIO_INPUT_MASK) { + val = mcp251x_read_reg(priv->spi, TXRTSCTRL); + val = FIELD_GET(TXRTSCTRL_RTS_MASK, val); + bits |= FIELD_PREP(MCP251X_GPIO_INPUT_MASK, val); + } + if (maskp[0] & MCP251X_GPIO_OUTPUT_MASK) { + val = mcp251x_read_reg(priv->spi, BFPCTRL); + val = FIELD_GET(BFPCTRL_BFS_MASK, val); + bits |= FIELD_PREP(MCP251X_GPIO_OUTPUT_MASK, val); + } + mutex_unlock(&priv->mcp_lock); + + bitsp[0] = bits; + return 0; +} + +static void mcp251x_gpio_set(struct gpio_chip *chip, unsigned int offset, + int value) +{ + struct mcp251x_priv *priv = gpiochip_get_data(chip); + u8 mask, val; + + mask = BFPCTRL_BFS(offset - MCP251X_GPIO_RX0BF); + val = value ? mask : 0; + + mutex_lock(&priv->mcp_lock); + mcp251x_write_bits(priv->spi, BFPCTRL, mask, val); + mutex_unlock(&priv->mcp_lock); + + priv->reg_bfpctrl &= ~mask; + priv->reg_bfpctrl |= val; +} + +static void +mcp251x_gpio_set_multiple(struct gpio_chip *chip, + unsigned long *maskp, unsigned long *bitsp) +{ + struct mcp251x_priv *priv = gpiochip_get_data(chip); + u8 mask, val; + + mask = FIELD_GET(MCP251X_GPIO_OUTPUT_MASK, maskp[0]); + mask = FIELD_PREP(BFPCTRL_BFS_MASK, mask); + + val = FIELD_GET(MCP251X_GPIO_OUTPUT_MASK, bitsp[0]); + val = FIELD_PREP(BFPCTRL_BFS_MASK, val); + + if (!mask) + return; + + mutex_lock(&priv->mcp_lock); + mcp251x_write_bits(priv->spi, BFPCTRL, mask, val); + mutex_unlock(&priv->mcp_lock); + + priv->reg_bfpctrl &= ~mask; + priv->reg_bfpctrl |= val; +} + +static void mcp251x_gpio_restore(struct spi_device *spi) +{ + struct mcp251x_priv *priv = spi_get_drvdata(spi); + + mcp251x_write_reg(spi, BFPCTRL, priv->reg_bfpctrl); +} + +static int mcp251x_gpio_setup(struct mcp251x_priv *priv) +{ + struct gpio_chip *gpio = &priv->gpio; + + if (!device_property_present(&priv->spi->dev, "gpio-controller")) + return 0; + + /* gpiochip handles TX[0..2]RTS and RX[0..1]BF */ + gpio->label = priv->spi->modalias; + gpio->parent = &priv->spi->dev; + gpio->owner = THIS_MODULE; + gpio->request = mcp251x_gpio_request; + gpio->free = mcp251x_gpio_free; + gpio->get_direction = mcp251x_gpio_get_direction; + gpio->get = mcp251x_gpio_get; + gpio->get_multiple = mcp251x_gpio_get_multiple; + gpio->set = mcp251x_gpio_set; + gpio->set_multiple = mcp251x_gpio_set_multiple; + gpio->base = -1; + gpio->ngpio = ARRAY_SIZE(mcp251x_gpio_names); + gpio->names = mcp251x_gpio_names; + gpio->can_sleep = true; +#ifdef CONFIG_OF_GPIO + gpio->of_node = priv->spi->dev.of_node; +#endif + + return devm_gpiochip_add_data(&priv->spi->dev, gpio, priv); +} +#else +static inline void mcp251x_gpio_restore(struct spi_device *spi) +{ +} + +static inline int mcp251x_gpio_setup(struct mcp251x_priv *priv) +{ + return 0; +} +#endif + static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf, int len, int tx_buf_idx) { @@ -761,6 +999,7 @@ static void mcp251x_restart_work_handler(struct work_struct *ws) if (priv->after_suspend & AFTER_SUSPEND_POWER) { mcp251x_hw_reset(spi); mcp251x_setup(net, spi); + mcp251x_gpio_restore(spi); } else { mcp251x_hw_wake(spi); } @@ -1136,6 +1375,10 @@ static int mcp251x_can_probe(struct spi_device *spi) devm_can_led_init(net); + ret = mcp251x_gpio_setup(priv); + if (ret) + goto error_probe; + netdev_info(net, "MCP%x successfully initialized.\n", priv->model); return 0; -- 2.28.0
