1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * LP5521 LED chip driver.
4 *
5 * Copyright (C) 2010 Nokia Corporation
6 * Copyright (C) 2012 Texas Instruments
7 *
8 * Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
9 * Milo(Woogyom) Kim <milo.kim@ti.com>
10 */
11
12 #include <linux/cleanup.h>
13 #include <linux/delay.h>
14 #include <linux/firmware.h>
15 #include <linux/i2c.h>
16 #include <linux/leds.h>
17 #include <linux/module.h>
18 #include <linux/mutex.h>
19 #include <linux/platform_data/leds-lp55xx.h>
20 #include <linux/slab.h>
21 #include <linux/of.h>
22
23 #include "leds-lp55xx-common.h"
24
25 #define LP5521_MAX_LEDS 3
26 #define LP5521_CMD_DIRECT 0x3F
27
28 /* Registers */
29 #define LP5521_REG_ENABLE 0x00
30 #define LP5521_REG_OP_MODE 0x01
31 #define LP5521_REG_R_PWM 0x02
32 #define LP5521_REG_G_PWM 0x03
33 #define LP5521_REG_B_PWM 0x04
34 #define LP5521_REG_R_CURRENT 0x05
35 #define LP5521_REG_G_CURRENT 0x06
36 #define LP5521_REG_B_CURRENT 0x07
37 #define LP5521_REG_CONFIG 0x08
38 #define LP5521_REG_STATUS 0x0C
39 #define LP5521_REG_RESET 0x0D
40 #define LP5521_REG_R_PROG_MEM 0x10
41 #define LP5521_REG_G_PROG_MEM 0x30
42 #define LP5521_REG_B_PROG_MEM 0x50
43
44 /* Base register to set LED current */
45 #define LP5521_REG_LED_CURRENT_BASE LP5521_REG_R_CURRENT
46 /* Base register to set the brightness */
47 #define LP5521_REG_LED_PWM_BASE LP5521_REG_R_PWM
48
49 /* Bits in ENABLE register */
50 #define LP5521_MASTER_ENABLE 0x40 /* Chip master enable */
51 #define LP5521_LOGARITHMIC_PWM 0x80 /* Logarithmic PWM adjustment */
52 #define LP5521_EXEC_RUN 0x2A
53 #define LP5521_ENABLE_DEFAULT \
54 (LP5521_MASTER_ENABLE | LP5521_LOGARITHMIC_PWM)
55 #define LP5521_ENABLE_RUN_PROGRAM \
56 (LP5521_ENABLE_DEFAULT | LP5521_EXEC_RUN)
57
58 /* CONFIG register */
59 #define LP5521_PWM_HF 0x40 /* PWM: 0 = 256Hz, 1 = 558Hz */
60 #define LP5521_PWRSAVE_EN 0x20 /* 1 = Power save mode */
61 #define LP5521_CP_MODE_MASK 0x18 /* Charge pump mode */
62 #define LP5521_CP_MODE_SHIFT 3
63 #define LP5521_R_TO_BATT 0x04 /* R out: 0 = CP, 1 = Vbat */
64 #define LP5521_CLK_INT 0x01 /* Internal clock */
65 #define LP5521_DEFAULT_CFG (LP5521_PWM_HF | LP5521_PWRSAVE_EN)
66
67 /* Status */
68 #define LP5521_EXT_CLK_USED 0x08
69
70 /* default R channel current register value */
71 #define LP5521_REG_R_CURR_DEFAULT 0xAF
72
73 /* Reset register value */
74 #define LP5521_RESET 0xFF
75
lp5521_wait_opmode_done(void)76 static inline void lp5521_wait_opmode_done(void)
77 {
78 /* operation mode change needs to be longer than 153 us */
79 usleep_range(200, 300);
80 }
81
lp5521_wait_enable_done(void)82 static inline void lp5521_wait_enable_done(void)
83 {
84 /* it takes more 488 us to update ENABLE register */
85 usleep_range(500, 600);
86 }
87
lp5521_run_engine(struct lp55xx_chip * chip,bool start)88 static void lp5521_run_engine(struct lp55xx_chip *chip, bool start)
89 {
90 int ret;
91
92 /* stop engine */
93 if (!start) {
94 lp55xx_stop_engine(chip);
95 lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
96 lp5521_wait_opmode_done();
97 return;
98 }
99
100 ret = lp55xx_run_engine_common(chip);
101 if (!ret)
102 lp5521_wait_enable_done();
103 }
104
lp5521_post_init_device(struct lp55xx_chip * chip)105 static int lp5521_post_init_device(struct lp55xx_chip *chip)
106 {
107 int ret;
108 u8 val;
109
110 /*
111 * Make sure that the chip is reset by reading back the r channel
112 * current reg. This is dummy read is required on some platforms -
113 * otherwise further access to the R G B channels in the
114 * LP5521_REG_ENABLE register will not have any effect - strange!
115 */
116 ret = lp55xx_read(chip, LP5521_REG_R_CURRENT, &val);
117 if (ret) {
118 dev_err(&chip->cl->dev, "error in resetting chip\n");
119 return ret;
120 }
121 if (val != LP5521_REG_R_CURR_DEFAULT) {
122 dev_err(&chip->cl->dev,
123 "unexpected data in register (expected 0x%x got 0x%x)\n",
124 LP5521_REG_R_CURR_DEFAULT, val);
125 ret = -EINVAL;
126 return ret;
127 }
128 usleep_range(10000, 20000);
129
130 /* Set all PWMs to direct control mode */
131 ret = lp55xx_write(chip, LP5521_REG_OP_MODE, LP5521_CMD_DIRECT);
132 if (ret)
133 return ret;
134
135 /* Update configuration for the clock setting */
136 val = LP5521_DEFAULT_CFG;
137 if (!lp55xx_is_extclk_used(chip))
138 val |= LP5521_CLK_INT;
139
140 val |= (chip->pdata->charge_pump_mode << LP5521_CP_MODE_SHIFT) & LP5521_CP_MODE_MASK;
141
142 ret = lp55xx_write(chip, LP5521_REG_CONFIG, val);
143 if (ret)
144 return ret;
145
146 /* Initialize all channels PWM to zero -> leds off */
147 lp55xx_write(chip, LP5521_REG_R_PWM, 0);
148 lp55xx_write(chip, LP5521_REG_G_PWM, 0);
149 lp55xx_write(chip, LP5521_REG_B_PWM, 0);
150
151 /* Set engines are set to run state when OP_MODE enables engines */
152 ret = lp55xx_write(chip, LP5521_REG_ENABLE, LP5521_ENABLE_RUN_PROGRAM);
153 if (ret)
154 return ret;
155
156 lp5521_wait_enable_done();
157
158 return 0;
159 }
160
lp5521_run_selftest(struct lp55xx_chip * chip,char * buf)161 static int lp5521_run_selftest(struct lp55xx_chip *chip, char *buf)
162 {
163 struct lp55xx_platform_data *pdata = chip->pdata;
164 int ret;
165 u8 status;
166
167 ret = lp55xx_read(chip, LP5521_REG_STATUS, &status);
168 if (ret < 0)
169 return ret;
170
171 if (pdata->clock_mode != LP55XX_CLOCK_EXT)
172 return 0;
173
174 /* Check that ext clock is really in use if requested */
175 if ((status & LP5521_EXT_CLK_USED) == 0)
176 return -EIO;
177
178 return 0;
179 }
180
lp5521_selftest(struct device * dev,struct device_attribute * attr,char * buf)181 static ssize_t lp5521_selftest(struct device *dev,
182 struct device_attribute *attr,
183 char *buf)
184 {
185 struct lp55xx_led *led = i2c_get_clientdata(to_i2c_client(dev));
186 struct lp55xx_chip *chip = led->chip;
187 int ret;
188
189 guard(mutex)(&chip->lock);
190
191 ret = lp5521_run_selftest(chip, buf);
192
193 return sysfs_emit(buf, "%s\n", ret ? "FAIL" : "OK");
194 }
195
196 /* device attributes */
197 LP55XX_DEV_ATTR_ENGINE_MODE(1);
198 LP55XX_DEV_ATTR_ENGINE_MODE(2);
199 LP55XX_DEV_ATTR_ENGINE_MODE(3);
200 LP55XX_DEV_ATTR_ENGINE_LOAD(1);
201 LP55XX_DEV_ATTR_ENGINE_LOAD(2);
202 LP55XX_DEV_ATTR_ENGINE_LOAD(3);
203 static LP55XX_DEV_ATTR_RO(selftest, lp5521_selftest);
204
205 static struct attribute *lp5521_attributes[] = {
206 &dev_attr_engine1_mode.attr,
207 &dev_attr_engine2_mode.attr,
208 &dev_attr_engine3_mode.attr,
209 &dev_attr_engine1_load.attr,
210 &dev_attr_engine2_load.attr,
211 &dev_attr_engine3_load.attr,
212 &dev_attr_selftest.attr,
213 NULL
214 };
215
216 static const struct attribute_group lp5521_group = {
217 .attrs = lp5521_attributes,
218 };
219
220 /* Chip specific configurations */
221 static struct lp55xx_device_config lp5521_cfg = {
222 .reg_op_mode = {
223 .addr = LP5521_REG_OP_MODE,
224 },
225 .reg_exec = {
226 .addr = LP5521_REG_ENABLE,
227 },
228 .reset = {
229 .addr = LP5521_REG_RESET,
230 .val = LP5521_RESET,
231 },
232 .enable = {
233 .addr = LP5521_REG_ENABLE,
234 .val = LP5521_ENABLE_DEFAULT,
235 },
236 .prog_mem_base = {
237 .addr = LP5521_REG_R_PROG_MEM,
238 },
239 .reg_led_pwm_base = {
240 .addr = LP5521_REG_LED_PWM_BASE,
241 },
242 .reg_led_current_base = {
243 .addr = LP5521_REG_LED_CURRENT_BASE,
244 },
245 .max_channel = LP5521_MAX_LEDS,
246 .post_init_device = lp5521_post_init_device,
247 .brightness_fn = lp55xx_led_brightness,
248 .multicolor_brightness_fn = lp55xx_multicolor_brightness,
249 .set_led_current = lp55xx_set_led_current,
250 .firmware_cb = lp55xx_firmware_loaded_cb,
251 .run_engine = lp5521_run_engine,
252 .dev_attr_group = &lp5521_group,
253 };
254
255 static const struct i2c_device_id lp5521_id[] = {
256 { "lp5521", .driver_data = (kernel_ulong_t)&lp5521_cfg, }, /* Three channel chip */
257 { }
258 };
259 MODULE_DEVICE_TABLE(i2c, lp5521_id);
260
261 static const struct of_device_id of_lp5521_leds_match[] = {
262 { .compatible = "national,lp5521", .data = &lp5521_cfg, },
263 {},
264 };
265
266 MODULE_DEVICE_TABLE(of, of_lp5521_leds_match);
267
268 static struct i2c_driver lp5521_driver = {
269 .driver = {
270 .name = "lp5521",
271 .of_match_table = of_lp5521_leds_match,
272 },
273 .probe = lp55xx_probe,
274 .remove = lp55xx_remove,
275 .id_table = lp5521_id,
276 };
277
278 module_i2c_driver(lp5521_driver);
279
280 MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
281 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
282 MODULE_DESCRIPTION("LP5521 LED engine");
283 MODULE_LICENSE("GPL v2");
284