openwrt/target/linux/realtek/files-5.4/drivers/gpio/gpio-rtl8231.c
Birger Koblitz e1bca7c77d realtek: fix RTL8231 gpio expander usage with RTL839X SoC
This fixes the usage of the RTL8231 GPIO extender chip
when used with the RTL839X SoCs. Specifically,
the PHY addresses may be different from 0.

Signed-off-by: Birger Koblitz <git@birger-koblitz.de>
2021-01-26 15:06:50 +01:00

338 lines
7.8 KiB
C

// 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_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
struct rtl8231_gpios {
struct gpio_chip gc;
struct device *dev;
u32 id;
int smi_bus_id;
u16 reg_shadow[0x20];
u32 reg_cached;
int ext_gpio_indrt_access;
};
extern struct mutex smi_lock;
extern struct rtl83xx_soc_info soc_info;
static u32 rtl8231_read(struct rtl8231_gpios *gpios, u32 reg)
{
u32 t = 0, n = 0;
u8 bus_id = gpios->smi_bus_id;
reg &= 0x1f;
bus_id &= 0x1f;
/* Calculate read register address */
t = (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__, 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;
u8 bus_id = gpios->smi_bus_id;
pr_debug("%s: %x, %x, %x\n", __func__, bus_id, reg, data);
reg &= 0x1f;
bus_id &= 0x1f;
t = (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 pin = gpio % 16;
int dpin = pin;
if (gpio > 31) {
pr_debug("WARNING: HIGH pin\n");
dpin = pin << 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 = 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(&smi_lock);
err = rtl8231_pin_dir(gpios, offset, 1);
mutex_unlock(&smi_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(&smi_lock);
err = rtl8231_pin_dir(gpios, offset, 0);
mutex_unlock(&smi_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(&smi_lock);
rtl8231_pin_dir_get(gpios, offset, &v);
mutex_unlock(&smi_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(&smi_lock);
rtl8231_pin_get(gpios, offset, &state);
mutex_unlock(&smi_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)
{
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);
}
/*Select GPIO functionality for pins 0-15, 16-31 and 32-37 */
rtl8231_write(gpios, RTL8231_GPIO_PIN_SEL(0), 0xffff);
rtl8231_write(gpios, RTL8231_GPIO_PIN_SEL(16), 0xffff);
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;
u32 indirect_bus_id;
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;
}
/*
* We use a default MDIO bus ID for the 8231 of 0, which can be overriden
* by the indirect-access-bus-id property in the dts.
*/
gpios->smi_bus_id = 0;
of_property_read_u32(np, "indirect-access-bus-id", &indirect_bus_id);
gpios->smi_bus_id = indirect_bus_id;
rtl8231_init(gpios);
gpios->dev = dev;
gpios->gc.base = 160;
gpios->gc.ngpio = 36;
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;
err = devm_gpiochip_add_data(dev, &gpios->gc, gpios);
return err;
}
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");