msm8916-openwrt/target/linux/realtek/files-5.15/drivers/gpio/gpio-rtl8231.c
Olliver Schinagl 0a931767cf realtek: Replace C++ style comments
The only exception to C++ style comments are SPDX license identifier
markers at the start of C files (even headers have C style markers).

Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
2022-12-27 16:33:01 +01:00

365 lines
8.4 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_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");