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LegoLivesMatterlag-linaro
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leds: ktd2692: Convert to use ExpressWire library
The KTD2692 uses the ExpressWire protocol implemented in the newly introduced ExpressWire library. Convert the driver to use the library. Suggested-by: Daniel Thompson <[email protected]> Reviewed-by: Linus Walleij <[email protected]> Reviewed-by: Daniel Thompson <[email protected]> Signed-off-by: Duje Mihanović <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Lee Jones <[email protected]>
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‎drivers/leds/flash/Kconfig

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -23,7 +23,7 @@ config LEDS_AS3645A
2323
config LEDS_KTD2692
2424
tristate "LED support for Kinetic KTD2692 flash LED controller"
2525
depends on OF
26-
depends on GPIOLIB || COMPILE_TEST
26+
select LEDS_EXPRESSWIRE
2727
help
2828
This option enables support for Kinetic KTD2692 LED flash connected
2929
through ExpressWire interface.

‎drivers/leds/flash/leds-ktd2692.c

Lines changed: 27 additions & 89 deletions
Original file line numberDiff line numberDiff line change
@@ -6,9 +6,9 @@
66
* Ingi Kim <[email protected]>
77
*/
88

9-
#include <linux/delay.h>
109
#include <linux/err.h>
1110
#include <linux/gpio/consumer.h>
11+
#include <linux/leds-expresswire.h>
1212
#include <linux/led-class-flash.h>
1313
#include <linux/module.h>
1414
#include <linux/mutex.h>
@@ -37,22 +37,9 @@
3737
#define KTD2692_REG_FLASH_CURRENT_BASE 0x80
3838
#define KTD2692_REG_MODE_BASE 0xA0
3939

40-
/* Set bit coding time for expresswire interface */
41-
#define KTD2692_TIME_RESET_US 700
42-
#define KTD2692_TIME_DATA_START_TIME_US 10
43-
#define KTD2692_TIME_HIGH_END_OF_DATA_US 350
44-
#define KTD2692_TIME_LOW_END_OF_DATA_US 10
45-
#define KTD2692_TIME_SHORT_BITSET_US 4
46-
#define KTD2692_TIME_LONG_BITSET_US 12
47-
4840
/* KTD2692 default length of name */
4941
#define KTD2692_NAME_LENGTH 20
5042

51-
enum ktd2692_bitset {
52-
KTD2692_LOW = 0,
53-
KTD2692_HIGH,
54-
};
55-
5643
/* Movie / Flash Mode Control */
5744
enum ktd2692_led_mode {
5845
KTD2692_MODE_DISABLE = 0, /* default */
@@ -71,7 +58,19 @@ struct ktd2692_led_config_data {
7158
enum led_brightness max_brightness;
7259
};
7360

61+
const struct expresswire_timing ktd2692_timing = {
62+
.poweroff_us = 700,
63+
.data_start_us = 10,
64+
.end_of_data_low_us = 10,
65+
.end_of_data_high_us = 350,
66+
.short_bitset_us = 4,
67+
.long_bitset_us = 12
68+
};
69+
7470
struct ktd2692_context {
71+
/* Common ExpressWire properties (ctrl GPIO and timing) */
72+
struct expresswire_common_props props;
73+
7574
/* Related LED Flash class device */
7675
struct led_classdev_flash fled_cdev;
7776

@@ -80,7 +79,6 @@ struct ktd2692_context {
8079
struct regulator *regulator;
8180

8281
struct gpio_desc *aux_gpio;
83-
struct gpio_desc *ctrl_gpio;
8482

8583
enum ktd2692_led_mode mode;
8684
enum led_brightness torch_brightness;
@@ -92,67 +90,6 @@ static struct ktd2692_context *fled_cdev_to_led(
9290
return container_of(fled_cdev, struct ktd2692_context, fled_cdev);
9391
}
9492

95-
static void ktd2692_expresswire_start(struct ktd2692_context *led)
96-
{
97-
gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
98-
udelay(KTD2692_TIME_DATA_START_TIME_US);
99-
}
100-
101-
static void ktd2692_expresswire_reset(struct ktd2692_context *led)
102-
{
103-
gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
104-
udelay(KTD2692_TIME_RESET_US);
105-
}
106-
107-
static void ktd2692_expresswire_end(struct ktd2692_context *led)
108-
{
109-
gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
110-
udelay(KTD2692_TIME_LOW_END_OF_DATA_US);
111-
gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
112-
udelay(KTD2692_TIME_HIGH_END_OF_DATA_US);
113-
}
114-
115-
static void ktd2692_expresswire_set_bit(struct ktd2692_context *led, bool bit)
116-
{
117-
/*
118-
* The Low Bit(0) and High Bit(1) is based on a time detection
119-
* algorithm between time low and time high
120-
* Time_(L_LB) : Low time of the Low Bit(0)
121-
* Time_(H_LB) : High time of the LOW Bit(0)
122-
* Time_(L_HB) : Low time of the High Bit(1)
123-
* Time_(H_HB) : High time of the High Bit(1)
124-
*
125-
* It can be simplified to:
126-
* Low Bit(0) : 2 * Time_(H_LB) < Time_(L_LB)
127-
* High Bit(1) : 2 * Time_(L_HB) < Time_(H_HB)
128-
* HIGH ___ ____ _.. _________ ___
129-
* |_________| |_.. |____| |__|
130-
* LOW <L_LB> <H_LB> <L_HB> <H_HB>
131-
* [ Low Bit (0) ] [ High Bit(1) ]
132-
*/
133-
if (bit) {
134-
gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
135-
udelay(KTD2692_TIME_SHORT_BITSET_US);
136-
gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
137-
udelay(KTD2692_TIME_LONG_BITSET_US);
138-
} else {
139-
gpiod_direction_output(led->ctrl_gpio, KTD2692_LOW);
140-
udelay(KTD2692_TIME_LONG_BITSET_US);
141-
gpiod_direction_output(led->ctrl_gpio, KTD2692_HIGH);
142-
udelay(KTD2692_TIME_SHORT_BITSET_US);
143-
}
144-
}
145-
146-
static void ktd2692_expresswire_write(struct ktd2692_context *led, u8 value)
147-
{
148-
int i;
149-
150-
ktd2692_expresswire_start(led);
151-
for (i = 7; i >= 0; i--)
152-
ktd2692_expresswire_set_bit(led, value & BIT(i));
153-
ktd2692_expresswire_end(led);
154-
}
155-
15693
static int ktd2692_led_brightness_set(struct led_classdev *led_cdev,
15794
enum led_brightness brightness)
15895
{
@@ -163,14 +100,14 @@ static int ktd2692_led_brightness_set(struct led_classdev *led_cdev,
163100

164101
if (brightness == LED_OFF) {
165102
led->mode = KTD2692_MODE_DISABLE;
166-
gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
103+
gpiod_direction_output(led->aux_gpio, 0);
167104
} else {
168-
ktd2692_expresswire_write(led, brightness |
105+
expresswire_write_u8(&led->props, brightness |
169106
KTD2692_REG_MOVIE_CURRENT_BASE);
170107
led->mode = KTD2692_MODE_MOVIE;
171108
}
172109

173-
ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
110+
expresswire_write_u8(&led->props, led->mode | KTD2692_REG_MODE_BASE);
174111
mutex_unlock(&led->lock);
175112

176113
return 0;
@@ -187,17 +124,17 @@ static int ktd2692_led_flash_strobe_set(struct led_classdev_flash *fled_cdev,
187124

188125
if (state) {
189126
flash_tm_reg = GET_TIMEOUT_OFFSET(timeout->val, timeout->step);
190-
ktd2692_expresswire_write(led, flash_tm_reg
127+
expresswire_write_u8(&led->props, flash_tm_reg
191128
| KTD2692_REG_FLASH_TIMEOUT_BASE);
192129

193130
led->mode = KTD2692_MODE_FLASH;
194-
gpiod_direction_output(led->aux_gpio, KTD2692_HIGH);
131+
gpiod_direction_output(led->aux_gpio, 1);
195132
} else {
196133
led->mode = KTD2692_MODE_DISABLE;
197-
gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
134+
gpiod_direction_output(led->aux_gpio, 0);
198135
}
199136

200-
ktd2692_expresswire_write(led, led->mode | KTD2692_REG_MODE_BASE);
137+
expresswire_write_u8(&led->props, led->mode | KTD2692_REG_MODE_BASE);
201138

202139
fled_cdev->led_cdev.brightness = LED_OFF;
203140
led->mode = KTD2692_MODE_DISABLE;
@@ -247,12 +184,12 @@ static void ktd2692_init_flash_timeout(struct led_classdev_flash *fled_cdev,
247184
static void ktd2692_setup(struct ktd2692_context *led)
248185
{
249186
led->mode = KTD2692_MODE_DISABLE;
250-
ktd2692_expresswire_reset(led);
251-
gpiod_direction_output(led->aux_gpio, KTD2692_LOW);
187+
expresswire_power_off(&led->props);
188+
gpiod_direction_output(led->aux_gpio, 0);
252189

253-
ktd2692_expresswire_write(led, (KTD2692_MM_MIN_CURR_THRESHOLD_SCALE - 1)
190+
expresswire_write_u8(&led->props, (KTD2692_MM_MIN_CURR_THRESHOLD_SCALE - 1)
254191
| KTD2692_REG_MM_MIN_CURR_THRESHOLD_BASE);
255-
ktd2692_expresswire_write(led, KTD2692_FLASH_MODE_CURR_PERCENT(45)
192+
expresswire_write_u8(&led->props, KTD2692_FLASH_MODE_CURR_PERCENT(45)
256193
| KTD2692_REG_FLASH_CURRENT_BASE);
257194
}
258195

@@ -277,8 +214,8 @@ static int ktd2692_parse_dt(struct ktd2692_context *led, struct device *dev,
277214
if (!np)
278215
return -ENXIO;
279216

280-
led->ctrl_gpio = devm_gpiod_get(dev, "ctrl", GPIOD_ASIS);
281-
ret = PTR_ERR_OR_ZERO(led->ctrl_gpio);
217+
led->props.ctrl_gpio = devm_gpiod_get(dev, "ctrl", GPIOD_ASIS);
218+
ret = PTR_ERR_OR_ZERO(led->props.ctrl_gpio);
282219
if (ret)
283220
return dev_err_probe(dev, ret, "cannot get ctrl-gpios\n");
284221

@@ -412,6 +349,7 @@ static struct platform_driver ktd2692_driver = {
412349

413350
module_platform_driver(ktd2692_driver);
414351

352+
MODULE_IMPORT_NS(EXPRESSWIRE);
415353
MODULE_AUTHOR("Ingi Kim <[email protected]>");
416354
MODULE_DESCRIPTION("Kinetic KTD2692 LED driver");
417355
MODULE_LICENSE("GPL v2");

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