1 // SPDX-License-Identifier: GPL-2.0-only
3 #include <linux/gpio/driver.h>
4 #include <linux/module.h>
5 #include <linux/platform_device.h>
6 #include <linux/delay.h>
7 #include <asm/mach-rtl838x/mach-rtl83xx.h>
9 /* RTL8231 registers for LED control */
10 #define RTL8231_LED_FUNC0 0x0000
11 #define RTL8231_LED_FUNC1 0x0001
12 #define RTL8231_READY_MASK 0x03f0
13 #define RTL8231_READY_VALUE 0x0370
14 #define RTL8231_GPIO_PIN_SEL(gpio) ((0x0002) + ((gpio) >> 4))
15 #define RTL8231_GPIO_DIR(gpio) ((0x0005) + ((gpio) >> 4))
16 #define RTL8231_GPIO_DATA(gpio) ((0x001C) + ((gpio) >> 4))
18 #define USEC_TIMEOUT 5000
20 #define RTL8231_SMI_BUS_ID_MAX 0x1F
22 struct rtl8231_gpios
{
29 int ext_gpio_indrt_access
;
32 extern struct mutex smi_lock
;
33 extern struct rtl83xx_soc_info soc_info
;
35 static u32
rtl8231_read(struct rtl8231_gpios
*gpios
, u32 reg
)
41 /* Calculate read register address */
42 t
= (gpios
->smi_bus_id
<< 2) | (reg
<< 7);
44 /* Set execution bit: cleared when operation completed */
48 sw_w32(t
, gpios
->ext_gpio_indrt_access
);
51 t
= sw_r32(gpios
->ext_gpio_indrt_access
);
53 } while ((t
& 1) && (n
< USEC_TIMEOUT
));
55 if (n
>= USEC_TIMEOUT
)
58 pr_debug("%s: %x, %x, %x\n", __func__
, gpios
->smi_bus_id
,
59 reg
, (t
& 0xffff0000) >> 16);
61 return (t
& 0xffff0000) >> 16;
64 static int rtl8231_write(struct rtl8231_gpios
*gpios
, u32 reg
, u32 data
)
68 pr_debug("%s: %x, %x, %x\n", __func__
, gpios
->smi_bus_id
, reg
, data
);
71 t
= (gpios
->smi_bus_id
<< 2) | (reg
<< 7) | (data
<< 16);
75 /* Set execution bit: cleared when operation completed */
79 sw_w32(t
, gpios
->ext_gpio_indrt_access
);
82 t
= sw_r32(gpios
->ext_gpio_indrt_access
);
83 } while ((t
& 1) && (n
< USEC_TIMEOUT
));
85 if (n
>= USEC_TIMEOUT
)
91 static u32
rtl8231_read_cached(struct rtl8231_gpios
*gpios
, u32 reg
)
96 if (gpios
->reg_cached
& (1 << reg
))
97 return gpios
->reg_shadow
[reg
];
99 return rtl8231_read(gpios
, reg
);
102 /* Set Direction of the RTL8231 pin:
106 static int rtl8231_pin_dir(struct rtl8231_gpios
*gpios
, u32 gpio
, u32 dir
)
109 int pin_sel_addr
= RTL8231_GPIO_PIN_SEL(gpio
);
110 int pin_dir_addr
= RTL8231_GPIO_DIR(gpio
);
111 int dpin
= gpio
% 16;
114 pr_debug("WARNING: HIGH pin\n");
116 pin_dir_addr
= pin_sel_addr
;
119 v
= rtl8231_read_cached(gpios
, pin_dir_addr
);
120 if (v
& 0x80000000) {
121 pr_err("Error reading RTL8231\n");
125 v
= (v
& ~(1 << dpin
)) | (dir
<< dpin
);
126 rtl8231_write(gpios
, pin_dir_addr
, v
);
127 gpios
->reg_shadow
[pin_dir_addr
] = v
;
128 gpios
->reg_cached
|= 1 << pin_dir_addr
;
132 static int rtl8231_pin_dir_get(struct rtl8231_gpios
*gpios
, u32 gpio
, u32
*dir
)
139 int pin_dir_addr
= RTL8231_GPIO_DIR(gpio
);
143 pin_dir_addr
= RTL8231_GPIO_PIN_SEL(gpio
);
147 v
= rtl8231_read(gpios
, pin_dir_addr
);
155 static int rtl8231_pin_set(struct rtl8231_gpios
*gpios
, u32 gpio
, u32 data
)
157 u32 v
= rtl8231_read(gpios
, RTL8231_GPIO_DATA(gpio
));
159 pr_debug("%s: %d to %d\n", __func__
, gpio
, data
);
160 if (v
& 0x80000000) {
161 pr_err("Error reading RTL8231\n");
164 v
= (v
& ~(1 << (gpio
% 16))) | (data
<< (gpio
% 16));
165 rtl8231_write(gpios
, RTL8231_GPIO_DATA(gpio
), v
);
166 gpios
->reg_shadow
[RTL8231_GPIO_DATA(gpio
)] = v
;
167 gpios
->reg_cached
|= 1 << RTL8231_GPIO_DATA(gpio
);
171 static int rtl8231_pin_get(struct rtl8231_gpios
*gpios
, u32 gpio
, u16
*state
)
173 u32 v
= rtl8231_read(gpios
, RTL8231_GPIO_DATA(gpio
));
175 if (v
& 0x80000000) {
176 pr_err("Error reading RTL8231\n");
184 static int rtl8231_direction_input(struct gpio_chip
*gc
, unsigned int offset
)
187 struct rtl8231_gpios
*gpios
= gpiochip_get_data(gc
);
189 pr_debug("%s: %d\n", __func__
, offset
);
190 mutex_lock(&smi_lock
);
191 err
= rtl8231_pin_dir(gpios
, offset
, 1);
192 mutex_unlock(&smi_lock
);
196 static int rtl8231_direction_output(struct gpio_chip
*gc
, unsigned int offset
, int value
)
199 struct rtl8231_gpios
*gpios
= gpiochip_get_data(gc
);
201 pr_debug("%s: %d\n", __func__
, offset
);
202 mutex_lock(&smi_lock
);
203 err
= rtl8231_pin_dir(gpios
, offset
, 0);
204 mutex_unlock(&smi_lock
);
206 err
= rtl8231_pin_set(gpios
, offset
, value
);
210 static int rtl8231_get_direction(struct gpio_chip
*gc
, unsigned int offset
)
213 struct rtl8231_gpios
*gpios
= gpiochip_get_data(gc
);
215 pr_debug("%s: %d\n", __func__
, offset
);
216 mutex_lock(&smi_lock
);
217 rtl8231_pin_dir_get(gpios
, offset
, &v
);
218 mutex_unlock(&smi_lock
);
222 static int rtl8231_gpio_get(struct gpio_chip
*gc
, unsigned int offset
)
225 struct rtl8231_gpios
*gpios
= gpiochip_get_data(gc
);
227 mutex_lock(&smi_lock
);
228 rtl8231_pin_get(gpios
, offset
, &state
);
229 mutex_unlock(&smi_lock
);
230 if (state
& (1 << (offset
% 16)))
235 void rtl8231_gpio_set(struct gpio_chip
*gc
, unsigned int offset
, int value
)
237 struct rtl8231_gpios
*gpios
= gpiochip_get_data(gc
);
239 rtl8231_pin_set(gpios
, offset
, value
);
242 int rtl8231_init(struct rtl8231_gpios
*gpios
)
246 pr_info("%s called, MDIO bus ID: %d\n", __func__
, gpios
->smi_bus_id
);
248 gpios
->reg_cached
= 0;
250 if (soc_info
.family
== RTL8390_FAMILY_ID
) {
251 // RTL8390: Enable external gpio in global led control register
252 sw_w32_mask(0x7 << 18, 0x4 << 18, RTL839X_LED_GLB_CTRL
);
253 } else if (soc_info
.family
== RTL8380_FAMILY_ID
) {
254 // RTL8380: Enable RTL8231 indirect access mode
255 sw_w32_mask(0, 1, RTL838X_EXTRA_GPIO_CTRL
);
256 sw_w32_mask(3, 1, RTL838X_DMY_REG5
);
259 ret
= rtl8231_read(gpios
, RTL8231_LED_FUNC1
);
260 if ((ret
& 0x80000000) || ((ret
& RTL8231_READY_MASK
) != RTL8231_READY_VALUE
))
263 /* Select GPIO functionality and force input direction for pins 0-36 */
264 rtl8231_write(gpios
, RTL8231_GPIO_PIN_SEL(0), 0xffff);
265 rtl8231_write(gpios
, RTL8231_GPIO_DIR(0), 0xffff);
266 rtl8231_write(gpios
, RTL8231_GPIO_PIN_SEL(16), 0xffff);
267 rtl8231_write(gpios
, RTL8231_GPIO_DIR(16), 0xffff);
268 rtl8231_write(gpios
, RTL8231_GPIO_PIN_SEL(32), 0x03ff);
270 /* Set LED_Start to enable drivers for output mode */
271 rtl8231_write(gpios
, RTL8231_LED_FUNC0
, 1 << 1);
276 static const struct of_device_id rtl8231_gpio_of_match
[] = {
277 { .compatible
= "realtek,rtl8231-gpio" },
281 MODULE_DEVICE_TABLE(of
, rtl8231_gpio_of_match
);
283 static int rtl8231_gpio_probe(struct platform_device
*pdev
)
285 struct device
*dev
= &pdev
->dev
;
286 struct device_node
*np
= dev
->of_node
;
287 struct rtl8231_gpios
*gpios
;
290 pr_info("Probing RTL8231 GPIOs\n");
293 dev_err(&pdev
->dev
, "No DT found\n");
297 gpios
= devm_kzalloc(dev
, sizeof(*gpios
), GFP_KERNEL
);
301 gpios
->id
= soc_info
.id
;
302 if (soc_info
.family
== RTL8380_FAMILY_ID
) {
303 gpios
->ext_gpio_indrt_access
= RTL838X_EXT_GPIO_INDRT_ACCESS
;
306 if (soc_info
.family
== RTL8390_FAMILY_ID
) {
307 gpios
->ext_gpio_indrt_access
= RTL839X_EXT_GPIO_INDRT_ACCESS
;
310 err
= of_property_read_u32(np
, "indirect-access-bus-id", &gpios
->smi_bus_id
);
311 if (!err
&& gpios
->smi_bus_id
> RTL8231_SMI_BUS_ID_MAX
)
315 dev_err(dev
, "invalid or missing indirect-access-bus-id\n");
319 err
= rtl8231_init(gpios
);
321 dev_err(dev
, "no device found at bus address %d\n", gpios
->smi_bus_id
);
327 gpios
->gc
.ngpio
= 37;
328 gpios
->gc
.label
= "rtl8231";
329 gpios
->gc
.parent
= dev
;
330 gpios
->gc
.owner
= THIS_MODULE
;
331 gpios
->gc
.can_sleep
= true;
333 gpios
->gc
.direction_input
= rtl8231_direction_input
;
334 gpios
->gc
.direction_output
= rtl8231_direction_output
;
335 gpios
->gc
.set
= rtl8231_gpio_set
;
336 gpios
->gc
.get
= rtl8231_gpio_get
;
337 gpios
->gc
.get_direction
= rtl8231_get_direction
;
339 err
= devm_gpiochip_add_data(dev
, &gpios
->gc
, gpios
);
343 static struct platform_driver rtl8231_gpio_driver
= {
345 .name
= "rtl8231-gpio",
346 .of_match_table
= rtl8231_gpio_of_match
,
348 .probe
= rtl8231_gpio_probe
,
351 module_platform_driver(rtl8231_gpio_driver
);
353 MODULE_DESCRIPTION("Realtek RTL8231 GPIO expansion chip support");
354 MODULE_LICENSE("GPL v2");