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>
---
drivers/net/can/spi/mcp251x.c | 232 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 232 insertions(+)
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index 8d65b73..fb50392 100644
--- a/drivers/net/can/spi/mcp251x.c
+++ b/drivers/net/can/spi/mcp251x.c
@@ -38,6 +38,8 @@
#include <linux/spi/spi.h>
#include <linux/uaccess.h>
#include <linux/regulator/consumer.h>
+#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
/* SPI interface instruction set */
#define INSTRUCTION_WRITE 0x02
@@ -52,6 +54,15 @@
#define INSTRUCTION_RTS(n) (0x80 | ((n) & 0x07))
/* MPC251x registers */
+#define BFPCTRL 0x0c
+# define BFPCTRL_B0BFE 0x04
+# define BFPCTRL_B1BFE 0x08
+# define BFPCTRL_B0BFS 0x10
+# define BFPCTRL_B1BFS 0x20
+#define TXRTSCTRL 0x0d
+# define TXRTSCTRL_B0RTS 0x08
+# define TXRTSCTRL_B1RTS 0x10
+# define TXRTSCTRL_B2RTS 0x20
#define CANSTAT 0x0e
#define CANCTRL 0x0f
# define CANCTRL_REQOP_MASK 0xe0
@@ -225,6 +236,10 @@ 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) \
@@ -236,6 +251,10 @@ static inline int mcp251x_is_##_model(struct spi_device *spi) \
MCP251X_IS(2510);
+#ifdef CONFIG_GPIOLIB
+static void mcp251x_gpio_restore(struct spi_device *spi);
+#endif
+
static void mcp251x_clean(struct net_device *net)
{
struct mcp251x_priv *priv = netdev_priv(net);
@@ -761,6 +780,9 @@ 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);
+#ifdef CONFIG_GPIOLIB
+ mcp251x_gpio_restore(spi);
+#endif
} else {
mcp251x_hw_wake(spi);
}
@@ -918,6 +940,201 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
return IRQ_HANDLED;
}
+#ifdef CONFIG_GPIOLIB
+
+#define TX0RTS 0
+#define TX1RTS 1
+#define TX2RTS 2
+#define RX0BF 3
+#define RX1BF 4
+#define NGPIO 5
+
+static const char * const mcp251x_gpio_names[] = {
+ "TX0RTS",
+ "TX1RTS",
+ "TX2RTS",
+ "RX0BF",
+ "RX1BF"
+};
+
+static int mcp251x_gpio_request(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct mcp251x_priv *priv = gpiochip_get_data(chip);
+ u8 bit = BFPCTRL_B0BFE << (offset - RX0BF);
+
+ if (offset >= NGPIO)
+ return -EINVAL;
+ if (offset <= TX2RTS) // nothing to be done for inputs
+ return 0;
+
+ mutex_lock(&priv->mcp_lock);
+ mcp251x_write_bits(priv->spi, BFPCTRL, bit, bit);
+ mutex_unlock(&priv->mcp_lock);
+
+ priv->reg_bfpctrl = priv->reg_bfpctrl | bit;
+
+ return 0;
+}
+
+static void mcp251x_gpio_free(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ struct mcp251x_priv *priv = gpiochip_get_data(chip);
+ u8 bit = BFPCTRL_B0BFE << (offset - RX0BF);
+
+ if (offset >= NGPIO)
+ return;
+ if (offset <= TX2RTS) // nothing to be done for inputs
+ return;
+
+ mutex_lock(&priv->mcp_lock);
+ mcp251x_write_bits(priv->spi, BFPCTRL, bit, 0);
+ mutex_unlock(&priv->mcp_lock);
+
+ priv->reg_bfpctrl = priv->reg_bfpctrl & ~bit;
+}
+
+static int mcp251x_gpio_get_direction(struct gpio_chip *chip,
+ unsigned int offset)
+{
+ if (offset <= TX2RTS)
+ return GPIOF_DIR_IN;
+ else if (offset <= RX1BF)
+ return GPIOF_DIR_OUT;
+
+ return -EINVAL;
+}
+
+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 (offset <= TX2RTS) {
+ reg = TXRTSCTRL;
+ mask = TXRTSCTRL_B0RTS << offset;
+ } else if (offset <= RX1BF) {
+ reg = BFPCTRL;
+ mask = BFPCTRL_B0BFS << (offset - RX0BF);
+ } else {
+ return -EINVAL;
+ }
+
+ mutex_lock(&priv->mcp_lock);
+ val = mcp251x_read_reg(priv->spi, reg);
+ mutex_unlock(&priv->mcp_lock);
+
+ if (val & mask)
+ return 1;
+ return 0;
+}
+
+static int mcp251x_gpio_get_multiple(struct gpio_chip *chip,
+ unsigned long *mask, unsigned long *bits)
+{
+ struct mcp251x_priv *priv = gpiochip_get_data(chip);
+ unsigned long retbits = 0;
+
+ mutex_lock(&priv->mcp_lock);
+
+ if (mask[0] & GENMASK(TX2RTS, TX0RTS))
+ retbits |= mcp251x_read_reg(priv->spi, TXRTSCTRL)
+ >> __ffs(TXRTSCTRL_B0RTS);
+ if (mask[0] & GENMASK(RX1BF, RX0BF))
+ retbits |= (mcp251x_read_reg(priv->spi, BFPCTRL)
+ >> (__ffs(BFPCTRL_B0BFS) - RX0BF))
+ & GENMASK(RX1BF, RX0BF);
+
+ mutex_unlock(&priv->mcp_lock);
+
+ bits[0] = retbits;
+ 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, content;
+
+ if (offset < RX0BF)
+ return;
+
+ mask = BFPCTRL_B0BFS << (offset - RX0BF);
+ content = value ? mask : 0;
+
+ mutex_lock(&priv->mcp_lock);
+ mcp251x_write_bits(priv->spi, BFPCTRL, mask, content);
+ mutex_unlock(&priv->mcp_lock);
+
+ priv->reg_bfpctrl = (priv->reg_bfpctrl & ~mask) | content;
+}
+
+static void mcp251x_gpio_set_multiple(struct gpio_chip *chip,
+ unsigned long *mask, unsigned long *bits)
+{
+ struct mcp251x_priv *priv = gpiochip_get_data(chip);
+ u8 reg_mask = 0, value = 0;
+ int pin;
+
+ for (pin = RX0BF; pin <= RX1BF; pin++) {
+ if (test_bit(pin, mask)) {
+ u8 mask_val = BFPCTRL_B0BFS << (pin - RX0BF);
+
+ reg_mask |= mask_val;
+ if (test_bit(pin, bits))
+ value |= mask_val;
+ }
+ }
+
+ if (!reg_mask)
+ return;
+
+ mutex_lock(&priv->mcp_lock);
+ mcp251x_write_bits(priv->spi, BFPCTRL, reg_mask, value);
+ mutex_unlock(&priv->mcp_lock);
+
+ priv->reg_bfpctrl = (priv->reg_bfpctrl & ~reg_mask) | value;
+}
+
+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;
+
+ /* 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 = NGPIO;
+ gpio->names = mcp251x_gpio_names;
+ gpio->can_sleep = 1;
+
+ return gpiochip_add_data(gpio, priv);
+}
+
+static void mcp251x_gpio_remove(struct mcp251x_priv *priv)
+{
+ gpiochip_remove(&priv->gpio);
+}
+
+#endif // CONFIG_GPIOLIB
+
static int mcp251x_open(struct net_device *net)
{
struct mcp251x_priv *priv = netdev_priv(net);
@@ -1134,9 +1351,20 @@ static int mcp251x_can_probe(struct spi_device *spi)
devm_can_led_init(net);
+#ifdef CONFIG_GPIOLIB
+ ret = mcp251x_gpio_setup(priv);
+ if (ret)
+ goto error_gpio;
+#endif
+
netdev_info(net, "MCP%x successfully initialized.\n", priv->model);
return 0;
+#ifdef CONFIG_GPIOLIB
+error_gpio:
+ mcp251x_gpio_remove(priv);
+#endif
+
error_probe:
mcp251x_power_enable(priv->power, 0);
@@ -1157,6 +1385,10 @@ static int mcp251x_can_remove(struct spi_device *spi)
unregister_candev(net);
+#ifdef CONFIG_GPIOLIB
+ mcp251x_gpio_remove(priv);
+#endif
+
mcp251x_power_enable(priv->power, 0);
clk_disable_unprepare(priv->clk);
--
2.7.2
