[PATCH 2/2] gpio: mcp23s08: add pinconf support

From: Sebastian Reichel
Date: Fri Jan 27 2017 - 09:57:31 EST

mcp23xxx device have configurable 100k pullup resistors. This adds
support for enabling them using pinctrl's pinconf interface.

Signed-off-by: Sebastian Reichel <sre@xxxxxxxxxx>
---
drivers/gpio/gpio-mcp23s08.c | 200 +++++++++++++++++++++++++++++++++++++------
1 file changed, 176 insertions(+), 24 deletions(-)

diff --git a/drivers/gpio/gpio-mcp23s08.c b/drivers/gpio/gpio-mcp23s08.c
index bdb692345428..96abecaccc12 100644
--- a/drivers/gpio/gpio-mcp23s08.c
+++ b/drivers/gpio/gpio-mcp23s08.c
@@ -24,6 +24,10 @@
#include <linux/of_irq.h>
#include <linux/of_device.h>
#include <linux/regmap.h>
+#include <linux/pinctrl/pinconf.h>
+#include <linux/pinctrl/pinctrl.h>
+#include <linux/pinctrl/pinmux.h>
+#include <linux/pinctrl/pinconf-generic.h>

/**
* MCP types supported by driver
@@ -77,6 +81,9 @@ struct mcp23s08 {

struct regmap *regmap;
struct device *dev;
+
+ struct pinctrl_dev *pctldev;
+ struct pinctrl_desc pinctrl_desc;
};

static const struct regmap_config mcp23x08_regmap = {
@@ -96,6 +103,158 @@ static const struct regmap_config mcp23x17_regmap = {
.val_format_endian = REGMAP_ENDIAN_LITTLE,
};

+static int mcp_read(struct mcp23s08 *mcp, unsigned int reg, unsigned int *val)
+{
+ return regmap_read(mcp->regmap, reg << mcp->reg_shift, val);
+}
+
+static int mcp_write(struct mcp23s08 *mcp, unsigned int reg, unsigned int val)
+{
+ return regmap_write(mcp->regmap, reg << mcp->reg_shift, val);
+}
+
+static int mcp_set_bit(struct mcp23s08 *mcp, unsigned int reg,
+ unsigned int pin, bool enabled)
+{
+ u16 val = enabled ? 0xffff : 0x0000;
+ u16 mask = BIT(pin);
+ return regmap_update_bits(mcp->regmap, reg << mcp->reg_shift,
+ mask, val);
+}
+
+static int mcp_update_cache(struct mcp23s08 *mcp)
+{
+ int ret, reg, i;
+
+ for (i = 0; i < ARRAY_SIZE(mcp->cache); i++) {
+ ret = mcp_read(mcp, i, &reg);
+ if (ret < 0)
+ return ret;
+ mcp->cache[i] = reg;
+ }
+
+ return 0;
+}
+
+static const struct pinctrl_pin_desc mcp23x08_pins[] = {
+ PINCTRL_PIN(0, "gpio0"),
+ PINCTRL_PIN(1, "gpio1"),
+ PINCTRL_PIN(2, "gpio2"),
+ PINCTRL_PIN(3, "gpio3"),
+ PINCTRL_PIN(4, "gpio4"),
+ PINCTRL_PIN(5, "gpio5"),
+ PINCTRL_PIN(6, "gpio6"),
+ PINCTRL_PIN(7, "gpio7"),
+};
+
+static const struct pinctrl_pin_desc mcp23x17_pins[] = {
+ PINCTRL_PIN(0, "gpio0"),
+ PINCTRL_PIN(1, "gpio1"),
+ PINCTRL_PIN(2, "gpio2"),
+ PINCTRL_PIN(3, "gpio3"),
+ PINCTRL_PIN(4, "gpio4"),
+ PINCTRL_PIN(5, "gpio5"),
+ PINCTRL_PIN(6, "gpio6"),
+ PINCTRL_PIN(7, "gpio7"),
+ PINCTRL_PIN(8, "gpio8"),
+ PINCTRL_PIN(9, "gpio9"),
+ PINCTRL_PIN(10, "gpio10"),
+ PINCTRL_PIN(11, "gpio11"),
+ PINCTRL_PIN(12, "gpio12"),
+ PINCTRL_PIN(13, "gpio13"),
+ PINCTRL_PIN(14, "gpio14"),
+ PINCTRL_PIN(15, "gpio15"),
+};
+
+static int mcp_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
+{
+ return 0;
+}
+
+static const char *mcp_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
+ unsigned int group)
+{
+ return NULL;
+}
+
+static int mcp_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
+ unsigned int group,
+ const unsigned int **pins,
+ unsigned int *num_pins)
+{
+ return -ENOTSUPP;
+}
+
+static const struct pinctrl_ops mcp_pinctrl_ops = {
+ .get_groups_count = mcp_pinctrl_get_groups_count,
+ .get_group_name = mcp_pinctrl_get_group_name,
+ .get_group_pins = mcp_pinctrl_get_group_pins,
+#ifdef CONFIG_OF
+ .dt_node_to_map = pinconf_generic_dt_node_to_map_pin,
+ .dt_free_map = pinconf_generic_dt_free_map,
+#endif
+};
+
+static int mcp_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,
+ unsigned long *config)
+{
+ struct mcp23s08 *mcp = pinctrl_dev_get_drvdata(pctldev);
+ enum pin_config_param param = pinconf_to_config_param(*config);
+ unsigned int data, status;
+ int ret;
+
+ switch (param) {
+ case PIN_CONFIG_BIAS_PULL_UP:
+ ret = mcp_read(mcp, MCP_GPPU, &data);
+ if (ret < 0)
+ return ret;
+ status = (data & BIT(pin)) ? 1 : 0;
+ break;
+ default:
+ dev_err(mcp->dev, "Invalid config param %04x\n", param);
+ return -ENOTSUPP;
+ }
+
+ *config = 0;
+
+ return status ? 0 : -EINVAL;
+}
+
+static int mcp_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
+ unsigned long *configs, unsigned int num_configs)
+{
+ struct mcp23s08 *mcp = pinctrl_dev_get_drvdata(pctldev);
+ enum pin_config_param param;
+ u32 arg, mask;
+ u16 val;
+ int ret = 0;
+ int i;
+
+ for (i = 0; i < num_configs; i++) {
+ param = pinconf_to_config_param(configs[i]);
+ arg = pinconf_to_config_argument(configs[i]);
+
+ switch (param) {
+ case PIN_CONFIG_BIAS_PULL_UP:
+ val = arg ? 0xFFFF : 0x0000;
+ mask = BIT(pin);
+ ret = mcp_set_bit(mcp, MCP_GPPU, pin, arg);
+ break;
+ default:
+ dev_err(mcp->dev, "Invalid config param %04x\n", param);
+ return -ENOTSUPP;
+ }
+ }
+
+ return ret;
+}
+
+static const struct pinconf_ops mcp_pinconf_ops = {
+ .pin_config_get = mcp_pinconf_get,
+ .pin_config_set = mcp_pinconf_set,
+ .is_generic = true,
+};
+
/*----------------------------------------------------------------------*/

#ifdef CONFIG_SPI_MASTER
@@ -158,30 +317,6 @@ static const struct regmap_bus mcp23sxx_spi_regmap = {

#endif /* CONFIG_SPI_MASTER */

-static int mcp_read(struct mcp23s08 *mcp, unsigned int reg, unsigned int *val)
-{
- return regmap_read(mcp->regmap, reg << mcp->reg_shift, val);
-}
-
-static int mcp_write(struct mcp23s08 *mcp, unsigned int reg, unsigned int val)
-{
- return regmap_write(mcp->regmap, reg << mcp->reg_shift, val);
-}
-
-static int mcp_update_cache(struct mcp23s08 *mcp)
-{
- int ret, reg, i;
-
- for (i = 0; i < ARRAY_SIZE(mcp->cache); i++) {
- ret = mcp_read(mcp, i, &reg);
- if (ret < 0)
- return ret;
- mcp->cache[i] = reg;
- }
-
- return 0;
-}
-
/*----------------------------------------------------------------------*/

/* A given spi_device can represent up to eight mcp23sxx chips
@@ -627,6 +762,23 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
if (ret)
goto fail;
}
+
+ mcp->pinctrl_desc.name = "mcp23xxx-pinctrl";
+ mcp->pinctrl_desc.pctlops = &mcp_pinctrl_ops;
+ mcp->pinctrl_desc.confops = &mcp_pinconf_ops;
+ mcp->pinctrl_desc.npins = mcp->chip.ngpio;
+ if (mcp->pinctrl_desc.npins == 8)
+ mcp->pinctrl_desc.pins = mcp23x08_pins;
+ else if (mcp->pinctrl_desc.npins == 16)
+ mcp->pinctrl_desc.pins = mcp23x17_pins;
+ mcp->pinctrl_desc.owner = THIS_MODULE;
+
+ mcp->pctldev = pinctrl_register(&mcp->pinctrl_desc, dev, mcp);
+ if (IS_ERR(mcp->pctldev)) {
+ ret = PTR_ERR(mcp->pctldev);
+ goto fail;
+ }
+
fail:
if (ret < 0)
dev_dbg(dev, "can't setup chip %d, --> %d\n", addr, ret);
--
2.11.0