The RTL8231 GPIO and LED expander chip can be controlled via a MIIM or
I2C bus. A regmap interface is used to allow for portable code.
This patch only provides GPIO support, since this is the only known use,
as found on commercial devices.
Signed-off-by: Sander Vanheule <sander@xxxxxxxxxxxxx>
---
drivers/gpio/Kconfig | 9 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-rtl8231.c | 404 ++++++++++++++++++++++++++++++++++++
3 files changed, 414 insertions(+)
create mode 100644 drivers/gpio/gpio-rtl8231.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 20cc0012a5ef..982c87855510 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -521,6 +521,15 @@ config GPIO_REG
A 32-bit single register GPIO fixed in/out implementation. This
can be used to represent any register as a set of GPIO signals.
+config GPIO_RTL8231
+ tristate "Realtek RTL8231 GPIO expander"
+ select REGMAP_I2C
+ select REGMAP_MIIM
+ select OF_MDIO
+ help
+ RTL8231 GPIO and LED expander support.
+ When built as a module, the module will be called rtl8231_expander.
+
config GPIO_SAMA5D2_PIOBU
tristate "SAMA5D2 PIOBU GPIO support"
depends on MFD_SYSCON
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 7ba71922817e..7f22f0e5430e 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -126,6 +126,7 @@ obj-$(CONFIG_GPIO_RDA) += gpio-rda.o
obj-$(CONFIG_GPIO_RDC321X) += gpio-rdc321x.o
obj-$(CONFIG_GPIO_REALTEK_OTTO) += gpio-realtek-otto.o
obj-$(CONFIG_GPIO_REG) += gpio-reg.o
+obj-$(CONFIG_GPIO_RTL8231) += gpio-rtl8231.o
obj-$(CONFIG_ARCH_SA1100) += gpio-sa1100.o
obj-$(CONFIG_GPIO_SAMA5D2_PIOBU) += gpio-sama5d2-piobu.o
obj-$(CONFIG_GPIO_SCH311X) += gpio-sch311x.o
diff --git a/drivers/gpio/gpio-rtl8231.c b/drivers/gpio/gpio-rtl8231.c
new file mode 100644
index 000000000000..e0dfee68c859
--- /dev/null
+++ b/drivers/gpio/gpio-rtl8231.c
@@ -0,0 +1,404 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/gpio/driver.h>
+#include <linux/i2c.h>
+#include <linux/mdio.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_mdio.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+/* RTL8231 registers for LED control */
+#define RTL8231_FUNC0 0x00
+#define RTL8231_FUNC1 0x01
+#define RTL8231_PIN_MODE0 0x02
+#define RTL8231_PIN_MODE1 0x03
+#define RTL8231_PIN_HI_CFG 0x04
+#define RTL8231_GPIO_DIR0 0x05
+#define RTL8231_GPIO_DIR1 0x06
+#define RTL8231_GPIO_INVERT0 0x07
+#define RTL8231_GPIO_INVERT1 0x08
+#define RTL8231_GPIO_DATA0 0x1c
+#define RTL8231_GPIO_DATA1 0x1d
+#define RTL8231_GPIO_DATA2 0x1e
+
+#define RTL8231_READY_CODE_VALUE 0x37
+#define RTL8231_GPIO_DIR_IN 1
+#define RTL8231_GPIO_DIR_OUT 0
+
+#define RTL8231_MAX_GPIOS 37
+
+enum rtl8231_regfield {
+ RTL8231_FIELD_LED_START,
+ RTL8231_FIELD_READY_CODE,
+ RTL8231_FIELD_SOFT_RESET,
+ RTL8231_FIELD_PIN_MODE0,
+ RTL8231_FIELD_PIN_MODE1,
+ RTL8231_FIELD_PIN_MODE2,
+ RTL8231_FIELD_GPIO_DIR0,
+ RTL8231_FIELD_GPIO_DIR1,
+ RTL8231_FIELD_GPIO_DIR2,
+ RTL8231_FIELD_GPIO_DATA0,
+ RTL8231_FIELD_GPIO_DATA1,
+ RTL8231_FIELD_GPIO_DATA2,
+ RTL8231_FIELD_MAX
+};
+
+static const struct reg_field rtl8231_fields[RTL8231_FIELD_MAX] = {
+ [RTL8231_FIELD_LED_START] = REG_FIELD(RTL8231_FUNC0, 1, 1),
+ [RTL8231_FIELD_READY_CODE] = REG_FIELD(RTL8231_FUNC1, 4, 9),
+ [RTL8231_FIELD_SOFT_RESET] = REG_FIELD(RTL8231_PIN_HI_CFG, 15, 15),
+ [RTL8231_FIELD_PIN_MODE0] = REG_FIELD(RTL8231_PIN_MODE0, 0, 15),
+ [RTL8231_FIELD_PIN_MODE1] = REG_FIELD(RTL8231_PIN_MODE1, 0, 15),
+ [RTL8231_FIELD_PIN_MODE2] = REG_FIELD(RTL8231_PIN_HI_CFG, 0, 4),
+ [RTL8231_FIELD_GPIO_DIR0] = REG_FIELD(RTL8231_GPIO_DIR0, 0, 15),
+ [RTL8231_FIELD_GPIO_DIR1] = REG_FIELD(RTL8231_GPIO_DIR1, 0, 15),
+ [RTL8231_FIELD_GPIO_DIR2] = REG_FIELD(RTL8231_PIN_HI_CFG, 5, 9),
+ [RTL8231_FIELD_GPIO_DATA0] = REG_FIELD(RTL8231_GPIO_DATA0, 0, 15),
+ [RTL8231_FIELD_GPIO_DATA1] = REG_FIELD(RTL8231_GPIO_DATA1, 0, 15),
+ [RTL8231_FIELD_GPIO_DATA2] = REG_FIELD(RTL8231_GPIO_DATA2, 0, 4),
+};
+
+/**
+ * struct rtl8231_gpio_ctrl - Control data for an RTL8231 chip
+ *
+ * @gc: Associated gpio_chip instance
+ * @dev
+ * @fields
+ */
+struct rtl8231_gpio_ctrl {
+ struct gpio_chip gc;
+ struct device *dev;
+ struct regmap_field *fields[RTL8231_FIELD_MAX];
+};
+
+static int rtl8231_pin_read(struct rtl8231_gpio_ctrl *ctrl, int base, int offset)
+{
+ int field = base + offset / 16;
+ int bit = offset % 16;
+ unsigned int v;
+ int err;
+
+ err = regmap_field_read(ctrl->fields[field], &v);
+
+ if (err)
+ return err;
+
+ return !!(v & BIT(bit));
+}
+
+static int rtl8231_pin_write(struct rtl8231_gpio_ctrl *ctrl, int base, int offset, int val)
+{
+ int field = base + offset / 16;
+ int bit = offset % 16;
+
+ return regmap_field_update_bits(ctrl->fields[field], BIT(bit), val << bit);
+}
+
+static int rtl8231_direction_input(struct gpio_chip *gc, unsigned int offset)
+{
+ struct rtl8231_gpio_ctrl *ctrl = gpiochip_get_data(gc);
+
+ return rtl8231_pin_write(ctrl, RTL8231_FIELD_GPIO_DIR0, offset, RTL8231_GPIO_DIR_IN);
+}
+
+static int rtl8231_direction_output(struct gpio_chip *gc, unsigned int offset, int value)
+{
+ struct rtl8231_gpio_ctrl *ctrl = gpiochip_get_data(gc);
+ int err;
+
+ err = rtl8231_pin_write(ctrl, RTL8231_FIELD_GPIO_DIR0, offset, RTL8231_GPIO_DIR_OUT);
+ if (err)
+ return err;
+
+ return rtl8231_pin_write(ctrl, RTL8231_FIELD_GPIO_DATA0, offset, value);
+}
+
+static int rtl8231_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+ struct rtl8231_gpio_ctrl *ctrl = gpiochip_get_data(gc);
+
+ return rtl8231_pin_read(ctrl, RTL8231_FIELD_GPIO_DIR0, offset);
+}
+
+static int rtl8231_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+ struct rtl8231_gpio_ctrl *ctrl = gpiochip_get_data(gc);
+
+ return rtl8231_pin_read(ctrl, RTL8231_FIELD_GPIO_DATA0, offset);
+}
+
+static void rtl8231_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
+{
+ struct rtl8231_gpio_ctrl *ctrl = gpiochip_get_data(gc);
+
+ rtl8231_pin_write(ctrl, RTL8231_FIELD_GPIO_DATA0, offset, value);
+}
+
+static int rtl8231_gpio_get_multiple(struct gpio_chip *gc,
+ unsigned long *mask, unsigned long *bits)
+{
+ struct rtl8231_gpio_ctrl *ctrl = gpiochip_get_data(gc);
+ int read, field;
+ int offset, shift;
+ int sub_mask;
+ int value, err;
+
+ err = 0;
+ read = 0;
+ field = 0;
+
+ while (read < gc->ngpio) {
+ shift = read % (8 * sizeof(*bits));
+ offset = read / (8 * sizeof(*bits));
+ sub_mask = (mask[offset] >> shift) & 0xffff;
+ if (sub_mask) {
+ err = regmap_field_read(ctrl->fields[RTL8231_FIELD_GPIO_DATA0 + field],
+ &value);
+ if (err)
+ return err;
+ value = (sub_mask & value) << shift;
+ sub_mask <<= shift;
+ bits[offset] = (bits[offset] & ~sub_mask) | value;
+ }
+
+ field += 1;
+ read += 16;
+ }
+
+ return err;
+}
+
+static void rtl8231_gpio_set_multiple(struct gpio_chip *gc,
+ unsigned long *mask, unsigned long *bits)
+{
+ struct rtl8231_gpio_ctrl *ctrl = gpiochip_get_data(gc);
+ int read, field;
+ int offset, shift;
+ int sub_mask;
+ int value;
+
+ read = 0;
+ field = 0;
+
+ while (read < gc->ngpio) {
+ shift = read % (8 * sizeof(*bits));
+ offset = read / (8 * sizeof(*bits));
+ sub_mask = (mask[offset] >> shift) & 0xffff;
+ if (sub_mask) {
+ value = bits[offset] >> shift;
+ regmap_field_update_bits(ctrl->fields[RTL8231_FIELD_GPIO_DATA0 + field],
+ sub_mask, value);
+ }
+
+ field += 1;
+ read += 16;
+ }
+}
+
+static int rtl8231_init(struct rtl8231_gpio_ctrl *ctrl)
+{
+ unsigned int v;
+ int err;
+
+ err = regmap_field_read(ctrl->fields[RTL8231_FIELD_READY_CODE], &v);
+ if (err) {
+ dev_err(ctrl->dev, "failed to read READY_CODE\n");
+ return -ENODEV;
+ } else if (v != RTL8231_READY_CODE_VALUE) {
+ dev_err(ctrl->dev, "RTL8231 not present or ready 0x%x != 0x%x\n",
+ v, RTL8231_READY_CODE_VALUE);
+ return -ENODEV;
+ }
+
+ dev_info(ctrl->dev, "RTL8231 found\n");
+
+ /* If the device was already configured, just leave it alone */
+ err = regmap_field_read(ctrl->fields[RTL8231_FIELD_LED_START], &v);
+ if (err)
+ return err;
+ else if (v)
+ return 0;
+
+ regmap_field_write(ctrl->fields[RTL8231_FIELD_SOFT_RESET], 1);
+ regmap_field_write(ctrl->fields[RTL8231_FIELD_LED_START], 1);
+
+ /* Select GPIO functionality for all pins and set to input */
+ regmap_field_write(ctrl->fields[RTL8231_FIELD_PIN_MODE0], 0xffff);
+ regmap_field_write(ctrl->fields[RTL8231_FIELD_GPIO_DIR0], 0xffff);
+ regmap_field_write(ctrl->fields[RTL8231_FIELD_PIN_MODE1], 0xffff);
+ regmap_field_write(ctrl->fields[RTL8231_FIELD_GPIO_DIR1], 0xffff);
+ regmap_field_write(ctrl->fields[RTL8231_FIELD_PIN_MODE2], 0x1f);
+ regmap_field_write(ctrl->fields[RTL8231_FIELD_GPIO_DIR2], 0x1f);
+
+ return 0;
+}
+
+#define OF_COMPATIBLE_RTL8231_MDIO "realtek,rtl8231-mdio"
+#define OF_COMPATIBLE_RTL8231_I2C "realtek,rtl8231-i2c"
+
+static const struct of_device_id rtl8231_gpio_of_match[] = {
+ { .compatible = OF_COMPATIBLE_RTL8231_MDIO },
+ { .compatible = OF_COMPATIBLE_RTL8231_I2C },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, rtl8231_gpio_of_match);
+
+static struct regmap *rtl8231_gpio_regmap_mdio(struct device *dev, struct regmap_config *cfg)
+{
+ struct device_node *np = dev->of_node;
+ struct device_node *expander_np = NULL;
+ struct mdio_device *mdiodev;
+
+ expander_np = of_parse_phandle(np, "dev-handle", 0);
+ if (!expander_np) {
+ dev_err(dev, "missing dev-handle node\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ mdiodev = of_mdio_find_device(expander_np);
+ of_node_put(expander_np);
+
+ if (!mdiodev) {
+ dev_err(dev, "failed to find MDIO device\n");
+ return ERR_PTR(-EPROBE_DEFER);
+ }
+
+ cfg->reg_bits = 5;
+ return devm_regmap_init_miim(mdiodev, cfg);
+}
+
+static struct regmap *rtl8231_gpio_regmap_i2c(struct device *dev, struct regmap_config *cfg)
+{
+ struct device_node *np = dev->of_node;
+ struct i2c_client *i2cdev;
+ struct regmap *map;
+ u32 reg_width;
+
+ // TODO untested
+ i2cdev = of_find_i2c_device_by_node(np);
+ if (IS_ERR(i2cdev)) {
+ dev_err(dev, "failed to find I2C device\n");
+ return ERR_PTR(-ENODEV);
+ }
+
+ /* Complete 7-bit I2C address is [1 0 1 0 A2 A1 A0] */
+ if ((i2cdev->addr & ~(0x7)) != 0x50) {
+ dev_err(dev, "invalid address\n");
+ map = ERR_PTR(-EINVAL);
+ goto regmap_i2c_out;
+ }
+
+ if (of_property_read_u32(np, "realtek,regnum-width", ®_width)
+ || reg_width != 1 || reg_width != 2) {
+ dev_err(dev, "invalid realtek,regnum-width\n");
+ map = ERR_PTR(-EINVAL);
+ goto regmap_i2c_out;
+ }
+
+ cfg->reg_bits = 8*reg_width;
+ map = devm_regmap_init_i2c(i2cdev, cfg);
+
+regmap_i2c_out:
+ put_device(&i2cdev->dev);
+ return map;
+}
+
+static int rtl8231_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct regmap *map;
+ struct regmap_config regmap_cfg = {};
+ struct rtl8231_gpio_ctrl *ctrl;
+ int field, err;
+ u32 ngpios;
+
+ if (!np) {
+ dev_err(dev, "no DT node found\n");
+ return -EINVAL;
+ }
+
+ ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
+ if (!ctrl)
+ return -ENOMEM;
+
+ ngpios = RTL8231_MAX_GPIOS;
+ of_property_read_u32(np, "ngpios", &ngpios);
+ if (ngpios > RTL8231_MAX_GPIOS) {
+ dev_err(dev, "ngpios can be at most %d\n", RTL8231_MAX_GPIOS);
+ return -EINVAL;
+ }
+
+ regmap_cfg.val_bits = 16;
+ regmap_cfg.max_register = 30;
+ regmap_cfg.cache_type = REGCACHE_NONE;
+ regmap_cfg.num_ranges = 0;
+ regmap_cfg.use_single_read = true;
+ regmap_cfg.use_single_write = true;
+ regmap_cfg.reg_format_endian = REGMAP_ENDIAN_BIG;
+ regmap_cfg.val_format_endian = REGMAP_ENDIAN_BIG;
+
+ if (of_device_is_compatible(np, OF_COMPATIBLE_RTL8231_MDIO)) {
+ map = rtl8231_gpio_regmap_mdio(dev, ®map_cfg);
+ } else if (of_device_is_compatible(np, OF_COMPATIBLE_RTL8231_I2C)) {
+ map = rtl8231_gpio_regmap_i2c(dev, ®map_cfg);
+ } else {
+ dev_err(dev, "invalid bus type\n");
+ return -ENOTSUPP;
+ }
+
+ if (IS_ERR(map)) {
+ dev_err(dev, "failed to init regmap\n");
+ return PTR_ERR(map);
+ }
+
+ for (field = 0; field < RTL8231_FIELD_MAX; field++) {
+ ctrl->fields[field] = devm_regmap_field_alloc(dev, map, rtl8231_fields[field]);
+ if (IS_ERR(ctrl->fields[field])) {
+ dev_err(dev, "unable to allocate regmap field\n");
+ return PTR_ERR(ctrl->fields[field]);
+ }
+ }
+
+ ctrl->dev = dev;
+ err = rtl8231_init(ctrl);
+ if (err < 0)
+ return err;
+
+ ctrl->gc.base = -1;
+ ctrl->gc.ngpio = ngpios;
+ ctrl->gc.label = "rtl8231-gpio";
+ ctrl->gc.parent = dev;
+ ctrl->gc.owner = THIS_MODULE;
+ ctrl->gc.can_sleep = true;
+
+ ctrl->gc.set = rtl8231_gpio_set;
+ ctrl->gc.set_multiple = rtl8231_gpio_set_multiple;
+ ctrl->gc.get = rtl8231_gpio_get;
+ ctrl->gc.get_multiple = rtl8231_gpio_get_multiple;
+ ctrl->gc.direction_input = rtl8231_direction_input;
+ ctrl->gc.direction_output = rtl8231_direction_output;
+ ctrl->gc.get_direction = rtl8231_get_direction;
+
+ return devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
+}
+
+static struct platform_driver rtl8231_gpio_driver = {
+ .driver = {
+ .name = "rtl8231-expander",
+ .of_match_table = rtl8231_gpio_of_match,
+ },
+ .probe = rtl8231_gpio_probe,
+};
+module_platform_driver(rtl8231_gpio_driver);
+
+MODULE_AUTHOR("Sander Vanheule <sander@xxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Realtek RTL8231 GPIO and LED expander support");
+MODULE_LICENSE("GPL v2");
--
2.30.2
