Initial commit

target/linux/realtek/files-6.6/drivers/gpio/gpio-rtl8231.c

@@ -0,0 +1,364 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/gpio/driver.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <asm/mach-rtl838x/mach-rtl83xx.h>
+
+/* RTL8231 registers for LED control */
+#define RTL8231_LED_FUNC0			0x0000
+#define RTL8231_LED_FUNC1			0x0001
+#define RTL8231_READY_MASK			0x03f0
+#define RTL8231_READY_VALUE			0x0370
+#define RTL8231_GPIO_PIN_SEL(gpio)		((0x0002) + ((gpio) >> 4))
+#define RTL8231_GPIO_DIR(gpio)			((0x0005) + ((gpio) >> 4))
+#define RTL8231_GPIO_DATA(gpio)			((0x001C) + ((gpio) >> 4))
+
+#define USEC_TIMEOUT 5000
+
+#define RTL8231_SMI_BUS_ID_MAX			0x1F
+
+struct rtl8231_gpios {
+	struct gpio_chip gc;
+	struct device *dev;
+	u32 id;
+	u32 smi_bus_id;
+	u16 reg_shadow[0x20];
+	u32 reg_cached;
+	int ext_gpio_indrt_access;
+};
+
+extern struct rtl83xx_soc_info soc_info;
+
+DEFINE_MUTEX(miim_lock);
+
+static u32 rtl8231_read(struct rtl8231_gpios *gpios, u32 reg)
+{
+	u32 t = 0, n = 0;
+
+	reg &= 0x1f;
+
+	/* Calculate read register address */
+	t = (gpios->smi_bus_id << 2) | (reg << 7);
+
+	/* Set execution bit: cleared when operation completed */
+	t |= 1;
+
+	/* Start execution */
+	sw_w32(t, gpios->ext_gpio_indrt_access);
+	do {
+		udelay(1);
+		t = sw_r32(gpios->ext_gpio_indrt_access);
+		n++;
+	} while ((t & 1) && (n < USEC_TIMEOUT));
+
+	if (n >= USEC_TIMEOUT)
+		return 0x80000000;
+
+	pr_debug("%s: %x, %x, %x\n", __func__, gpios->smi_bus_id,
+		reg, (t & 0xffff0000) >> 16);
+
+	return (t & 0xffff0000) >> 16;
+}
+
+static int rtl8231_write(struct rtl8231_gpios *gpios, u32 reg, u32 data)
+{
+	u32 t = 0, n = 0;
+
+	pr_debug("%s: %x, %x, %x\n", __func__, gpios->smi_bus_id, reg, data);
+	reg &= 0x1f;
+
+	t = (gpios->smi_bus_id << 2) | (reg << 7) | (data << 16);
+	/* Set write bit */
+	t |= 2;
+
+	/* Set execution bit: cleared when operation completed */
+	t |= 1;
+
+	/* Start execution */
+	sw_w32(t, gpios->ext_gpio_indrt_access);
+	do {
+		udelay(1);
+		t = sw_r32(gpios->ext_gpio_indrt_access);
+	} while ((t & 1) && (n < USEC_TIMEOUT));
+
+	if (n >= USEC_TIMEOUT)
+		return -1;
+
+	return 0;
+}
+
+static u32 rtl8231_read_cached(struct rtl8231_gpios *gpios, u32 reg)
+{
+	if (reg > 0x1f)
+		return 0;
+
+	if (gpios->reg_cached & (1 << reg))
+		return gpios->reg_shadow[reg];
+
+	return rtl8231_read(gpios, reg);
+}
+
+/* Set Direction of the RTL8231 pin:
+ * dir 1: input
+ * dir 0: output
+ */
+static int rtl8231_pin_dir(struct rtl8231_gpios *gpios, u32 gpio, u32 dir)
+{
+	u32 v;
+	int pin_sel_addr = RTL8231_GPIO_PIN_SEL(gpio);
+	int pin_dir_addr = RTL8231_GPIO_DIR(gpio);
+	int dpin = gpio % 16;
+
+	if (gpio > 31) {
+		pr_debug("WARNING: HIGH pin\n");
+		dpin += 5;
+		pin_dir_addr = pin_sel_addr;
+	}
+
+	v = rtl8231_read_cached(gpios, pin_dir_addr);
+	if (v & 0x80000000) {
+		pr_err("Error reading RTL8231\n");
+		return -1;
+	}
+
+	v = (v & ~(1 << dpin)) | (dir << dpin);
+	rtl8231_write(gpios, pin_dir_addr, v);
+	gpios->reg_shadow[pin_dir_addr] = v;
+	gpios->reg_cached |= 1 << pin_dir_addr;
+
+	return 0;
+}
+
+static int rtl8231_pin_dir_get(struct rtl8231_gpios *gpios, u32 gpio, u32 *dir)
+{
+	/* dir 1: input
+	 * dir 0: output
+	 */
+
+	u32  v;
+	int pin_dir_addr = RTL8231_GPIO_DIR(gpio);
+	int pin = gpio % 16;
+
+	if (gpio > 31) {
+		pin_dir_addr = RTL8231_GPIO_PIN_SEL(gpio);
+		pin += 5;
+	}
+
+	v = rtl8231_read(gpios, pin_dir_addr);
+	if (v & (1 << pin))
+		*dir = 1;
+	else
+		*dir = 0;
+
+	return 0;
+}
+
+static int rtl8231_pin_set(struct rtl8231_gpios *gpios, u32 gpio, u32 data)
+{
+	u32 v = rtl8231_read(gpios, RTL8231_GPIO_DATA(gpio));
+
+	pr_debug("%s: %d to %d\n", __func__, gpio, data);
+	if (v & 0x80000000) {
+		pr_err("Error reading RTL8231\n");
+		return -1;
+	}
+	v = (v & ~(1 << (gpio % 16))) | (data << (gpio % 16));
+	rtl8231_write(gpios, RTL8231_GPIO_DATA(gpio), v);
+	gpios->reg_shadow[RTL8231_GPIO_DATA(gpio)] = v;
+	gpios->reg_cached |= 1 << RTL8231_GPIO_DATA(gpio);
+
+	return 0;
+}
+
+static int rtl8231_pin_get(struct rtl8231_gpios *gpios, u32 gpio, u16 *state)
+{
+	u32 v = rtl8231_read(gpios, RTL8231_GPIO_DATA(gpio));
+
+	if (v & 0x80000000) {
+		pr_err("Error reading RTL8231\n");
+		return -1;
+	}
+
+	*state = v & 0xffff;
+
+	return 0;
+}
+
+static int rtl8231_direction_input(struct gpio_chip *gc, unsigned int offset)
+{
+	int err;
+	struct rtl8231_gpios *gpios = gpiochip_get_data(gc);
+
+	pr_debug("%s: %d\n", __func__, offset);
+	mutex_lock(&miim_lock);
+	err = rtl8231_pin_dir(gpios, offset, 1);
+	mutex_unlock(&miim_lock);
+
+	return err;
+}
+
+static int rtl8231_direction_output(struct gpio_chip *gc, unsigned int offset, int value)
+{
+	int err;
+	struct rtl8231_gpios *gpios = gpiochip_get_data(gc);
+
+	pr_debug("%s: %d\n", __func__, offset);
+	mutex_lock(&miim_lock);
+	err = rtl8231_pin_dir(gpios, offset, 0);
+	mutex_unlock(&miim_lock);
+
+	if (!err)
+		err = rtl8231_pin_set(gpios, offset, value);
+
+	return err;
+}
+
+static int rtl8231_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+	u32 v = 0;
+	struct rtl8231_gpios *gpios = gpiochip_get_data(gc);
+
+	pr_debug("%s: %d\n", __func__, offset);
+	mutex_lock(&miim_lock);
+	rtl8231_pin_dir_get(gpios, offset, &v);
+	mutex_unlock(&miim_lock);
+
+	return v;
+}
+
+static int rtl8231_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+	u16 state = 0;
+	struct rtl8231_gpios *gpios = gpiochip_get_data(gc);
+
+	mutex_lock(&miim_lock);
+	rtl8231_pin_get(gpios, offset, &state);
+	mutex_unlock(&miim_lock);
+
+	if (state & (1 << (offset % 16)))
+		return 1;
+
+	return 0;
+}
+
+void rtl8231_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
+{
+	struct rtl8231_gpios *gpios = gpiochip_get_data(gc);
+
+	rtl8231_pin_set(gpios, offset, value);
+}
+
+int rtl8231_init(struct rtl8231_gpios *gpios)
+{
+	u32 ret;
+
+	pr_info("%s called, MDIO bus ID: %d\n", __func__, gpios->smi_bus_id);
+
+	gpios->reg_cached = 0;
+
+	if (soc_info.family == RTL8390_FAMILY_ID) {
+		/* RTL8390: Enable external gpio in global led control register */
+		sw_w32_mask(0x7 << 18, 0x4 << 18, RTL839X_LED_GLB_CTRL);
+	} else if (soc_info.family == RTL8380_FAMILY_ID) {
+		/* RTL8380: Enable RTL8231 indirect access mode */
+		sw_w32_mask(0, 1, RTL838X_EXTRA_GPIO_CTRL);
+		sw_w32_mask(3, 1, RTL838X_DMY_REG5);
+	}
+
+	ret = rtl8231_read(gpios, RTL8231_LED_FUNC1);
+	if ((ret & 0x80000000) || ((ret & RTL8231_READY_MASK) != RTL8231_READY_VALUE))
+		return -ENXIO;
+
+	/* Select GPIO functionality and force input direction for pins 0-36 */
+	rtl8231_write(gpios, RTL8231_GPIO_PIN_SEL(0), 0xffff);
+	rtl8231_write(gpios, RTL8231_GPIO_DIR(0), 0xffff);
+	rtl8231_write(gpios, RTL8231_GPIO_PIN_SEL(16), 0xffff);
+	rtl8231_write(gpios, RTL8231_GPIO_DIR(16), 0xffff);
+	rtl8231_write(gpios, RTL8231_GPIO_PIN_SEL(32), 0x03ff);
+
+	/* Set LED_Start to enable drivers for output mode */
+	rtl8231_write(gpios, RTL8231_LED_FUNC0, 1 << 1);
+
+	return 0;
+}
+
+static const struct of_device_id rtl8231_gpio_of_match[] = {
+	{ .compatible = "realtek,rtl8231-gpio" },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, rtl8231_gpio_of_match);
+
+static int rtl8231_gpio_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct rtl8231_gpios *gpios;
+	int err;
+
+	pr_info("Probing RTL8231 GPIOs\n");
+
+	if (!np) {
+		dev_err(&pdev->dev, "No DT found\n");
+		return -EINVAL;
+	}
+
+	gpios = devm_kzalloc(dev, sizeof(*gpios), GFP_KERNEL);
+	if (!gpios)
+		return -ENOMEM;
+
+	gpios->id = soc_info.id;
+	if (soc_info.family == RTL8380_FAMILY_ID) {
+		gpios->ext_gpio_indrt_access = RTL838X_EXT_GPIO_INDRT_ACCESS;
+	}
+
+	if (soc_info.family == RTL8390_FAMILY_ID) {
+		gpios->ext_gpio_indrt_access = RTL839X_EXT_GPIO_INDRT_ACCESS;
+	}
+
+	err = of_property_read_u32(np, "indirect-access-bus-id", &gpios->smi_bus_id);
+	if (!err && gpios->smi_bus_id > RTL8231_SMI_BUS_ID_MAX)
+		err = -EINVAL;
+
+	if (err) {
+		dev_err(dev, "invalid or missing indirect-access-bus-id\n");
+		return err;
+	}
+
+	err = rtl8231_init(gpios);
+	if (err) {
+		dev_err(dev, "no device found at bus address %d\n", gpios->smi_bus_id);
+		return err;
+	}
+
+	gpios->dev = dev;
+	gpios->gc.base = -1;
+	gpios->gc.ngpio = 37;
+	gpios->gc.label = "rtl8231";
+	gpios->gc.parent = dev;
+	gpios->gc.owner = THIS_MODULE;
+	gpios->gc.can_sleep = true;
+
+	gpios->gc.direction_input = rtl8231_direction_input;
+	gpios->gc.direction_output = rtl8231_direction_output;
+	gpios->gc.set = rtl8231_gpio_set;
+	gpios->gc.get = rtl8231_gpio_get;
+	gpios->gc.get_direction = rtl8231_get_direction;
+
+	return devm_gpiochip_add_data(dev, &gpios->gc, gpios);
+}
+
+static struct platform_driver rtl8231_gpio_driver = {
+	.driver = {
+		.name = "rtl8231-gpio",
+		.of_match_table	= rtl8231_gpio_of_match,
+	},
+	.probe = rtl8231_gpio_probe,
+};
+
+module_platform_driver(rtl8231_gpio_driver);
+
+MODULE_DESCRIPTION("Realtek RTL8231 GPIO expansion chip support");
+MODULE_LICENSE("GPL v2");