leds-lp5521.c

  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
 76static 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
 82static 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
 88static 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
105static 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
161static 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
181static 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 */
197LP55XX_DEV_ATTR_ENGINE_MODE(1);
198LP55XX_DEV_ATTR_ENGINE_MODE(2);
199LP55XX_DEV_ATTR_ENGINE_MODE(3);
200LP55XX_DEV_ATTR_ENGINE_LOAD(1);
201LP55XX_DEV_ATTR_ENGINE_LOAD(2);
202LP55XX_DEV_ATTR_ENGINE_LOAD(3);
203static LP55XX_DEV_ATTR_RO(selftest, lp5521_selftest);
204
205static 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
216static const struct attribute_group lp5521_group = {
217	.attrs = lp5521_attributes,
218};
219
220/* Chip specific configurations */
221static 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
255static const struct i2c_device_id lp5521_id[] = {
256	{ "lp5521", .driver_data = (kernel_ulong_t)&lp5521_cfg, }, /* Three channel chip */
257	{ }
258};
259MODULE_DEVICE_TABLE(i2c, lp5521_id);
260
261static const struct of_device_id of_lp5521_leds_match[] = {
262	{ .compatible = "national,lp5521", .data = &lp5521_cfg, },
263	{},
264};
265
266MODULE_DEVICE_TABLE(of, of_lp5521_leds_match);
267
268static 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
278module_i2c_driver(lp5521_driver);
279
280MODULE_AUTHOR("Mathias Nyman, Yuri Zaporozhets, Samu Onkalo");
281MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
282MODULE_DESCRIPTION("LP5521 LED engine");
283MODULE_LICENSE("GPL v2");