1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright 2007-2008 Extreme Engineering Solutions, Inc.
7 * LED driver for various PCA955x I2C LED drivers
11 * Device Description 7-bit slave address
12 * ------ ----------- -------------------
13 * PCA9550 2-bit driver 0x60 .. 0x61
14 * PCA9551 8-bit driver 0x60 .. 0x67
15 * PCA9552 16-bit driver 0x60 .. 0x67
16 * PCA9553/01 4-bit driver 0x62
17 * PCA9553/02 4-bit driver 0x63
19 * Philips PCA955x LED driver chips follow a register map as shown below:
21 * Control Register Description
22 * ---------------- -----------
23 * 0x0 Input register 0
25 * NUM_INPUT_REGS - 1 Last Input register X
27 * NUM_INPUT_REGS Frequency prescaler 0
28 * NUM_INPUT_REGS + 1 PWM register 0
29 * NUM_INPUT_REGS + 2 Frequency prescaler 1
30 * NUM_INPUT_REGS + 3 PWM register 1
32 * NUM_INPUT_REGS + 4 LED selector 0
34 * + NUM_LED_REGS - 1 Last LED selector
36 * where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many
37 * bits the chip supports.
40 #include <linux/bitops.h>
41 #include <linux/ctype.h>
42 #include <linux/delay.h>
43 #include <linux/err.h>
44 #include <linux/gpio/driver.h>
45 #include <linux/i2c.h>
46 #include <linux/leds.h>
47 #include <linux/module.h>
49 #include <linux/property.h>
50 #include <linux/slab.h>
51 #include <linux/string.h>
53 #include <dt-bindings/leds/leds-pca955x.h>
55 /* LED select registers determine the source that drives LED outputs */
56 #define PCA955X_LS_LED_ON 0x0 /* Output LOW */
57 #define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */
58 #define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */
59 #define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */
61 #define PCA955X_GPIO_INPUT LED_OFF
62 #define PCA955X_GPIO_HIGH LED_OFF
63 #define PCA955X_GPIO_LOW LED_FULL
73 struct pca955x_chipdef {
75 u8 slv_addr; /* 7-bit slave address mask */
76 int slv_addr_shift; /* Number of bits to ignore */
79 static const struct pca955x_chipdef pca955x_chipdefs[] = {
82 .slv_addr = /* 110000x */ 0x60,
87 .slv_addr = /* 1100xxx */ 0x60,
92 .slv_addr = /* 1100xxx */ 0x60,
97 .slv_addr = /* 0110xxx */ 0x30,
102 .slv_addr = /* 110001x */ 0x62,
109 struct pca955x_led *leds;
110 const struct pca955x_chipdef *chipdef;
111 struct i2c_client *client;
112 unsigned long active_pins;
113 #ifdef CONFIG_LEDS_PCA955X_GPIO
114 struct gpio_chip gpio;
119 struct pca955x *pca955x;
120 struct led_classdev led_cdev;
121 int led_num; /* 0 .. 15 potentially */
123 enum led_default_state default_state;
124 struct fwnode_handle *fwnode;
127 struct pca955x_platform_data {
128 struct pca955x_led *leds;
132 /* 8 bits per input register */
133 static inline int pca95xx_num_input_regs(int bits)
135 return (bits + 7) / 8;
139 * Return an LED selector register value based on an existing one, with
140 * the appropriate 2-bit state value set for the given LED number (0-3).
142 static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
144 return (oldval & (~(0x3 << (led_num << 1)))) |
145 ((state & 0x3) << (led_num << 1));
149 * Write to frequency prescaler register, used to program the
150 * period of the PWM output. period = (PSCx + 1) / 38
152 static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
154 struct pca955x *pca955x = i2c_get_clientdata(client);
155 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + (2 * n);
158 ret = i2c_smbus_write_byte_data(client, cmd, val);
160 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
161 __func__, n, val, ret);
166 * Write to PWM register, which determines the duty cycle of the
167 * output. LED is OFF when the count is less than the value of this
168 * register, and ON when it is greater. If PWMx == 0, LED is always OFF.
170 * Duty cycle is (256 - PWMx) / 256
172 static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
174 struct pca955x *pca955x = i2c_get_clientdata(client);
175 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
178 ret = i2c_smbus_write_byte_data(client, cmd, val);
180 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
181 __func__, n, val, ret);
186 * Write to LED selector register, which determines the source that
187 * drives the LED output.
189 static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
191 struct pca955x *pca955x = i2c_get_clientdata(client);
192 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n;
195 ret = i2c_smbus_write_byte_data(client, cmd, val);
197 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
198 __func__, n, val, ret);
203 * Read the LED selector register, which determines the source that
204 * drives the LED output.
206 static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val)
208 struct pca955x *pca955x = i2c_get_clientdata(client);
209 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n;
212 ret = i2c_smbus_read_byte_data(client, cmd);
214 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
222 static int pca955x_read_pwm(struct i2c_client *client, int n, u8 *val)
224 struct pca955x *pca955x = i2c_get_clientdata(client);
225 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
228 ret = i2c_smbus_read_byte_data(client, cmd);
230 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
238 static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev)
240 struct pca955x_led *pca955x_led = container_of(led_cdev,
243 struct pca955x *pca955x = pca955x_led->pca955x;
247 ret = pca955x_read_ls(pca955x->client, pca955x_led->led_num / 4, &ls);
251 ls = (ls >> ((pca955x_led->led_num % 4) << 1)) & 0x3;
253 case PCA955X_LS_LED_ON:
256 case PCA955X_LS_LED_OFF:
259 case PCA955X_LS_BLINK0:
262 case PCA955X_LS_BLINK1:
263 ret = pca955x_read_pwm(pca955x->client, 1, &pwm);
273 static int pca955x_led_set(struct led_classdev *led_cdev,
274 enum led_brightness value)
276 struct pca955x_led *pca955x_led;
277 struct pca955x *pca955x;
279 int chip_ls; /* which LSx to use (0-3 potentially) */
280 int ls_led; /* which set of bits within LSx to use (0-3) */
283 pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev);
284 pca955x = pca955x_led->pca955x;
286 chip_ls = pca955x_led->led_num / 4;
287 ls_led = pca955x_led->led_num % 4;
289 mutex_lock(&pca955x->lock);
291 ret = pca955x_read_ls(pca955x->client, chip_ls, &ls);
297 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
300 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
303 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
307 * Use PWM1 for all other values. This has the unwanted
308 * side effect of making all LEDs on the chip share the
309 * same brightness level if set to a value other than
310 * OFF, HALF, or FULL. But, this is probably better than
311 * just turning off for all other values.
313 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value);
316 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
320 ret = pca955x_write_ls(pca955x->client, chip_ls, ls);
323 mutex_unlock(&pca955x->lock);
328 #ifdef CONFIG_LEDS_PCA955X_GPIO
330 * Read the INPUT register, which contains the state of LEDs.
332 static int pca955x_read_input(struct i2c_client *client, int n, u8 *val)
334 int ret = i2c_smbus_read_byte_data(client, n);
337 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
346 static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
348 struct pca955x *pca955x = gpiochip_get_data(gc);
350 return test_and_set_bit(offset, &pca955x->active_pins) ? -EBUSY : 0;
353 static void pca955x_gpio_free_pin(struct gpio_chip *gc, unsigned int offset)
355 struct pca955x *pca955x = gpiochip_get_data(gc);
357 clear_bit(offset, &pca955x->active_pins);
360 static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset,
363 struct pca955x *pca955x = gpiochip_get_data(gc);
364 struct pca955x_led *led = &pca955x->leds[offset];
367 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH);
369 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW);
372 static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
375 pca955x_set_value(gc, offset, val);
378 static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
380 struct pca955x *pca955x = gpiochip_get_data(gc);
381 struct pca955x_led *led = &pca955x->leds[offset];
384 /* There is nothing we can do about errors */
385 pca955x_read_input(pca955x->client, led->led_num / 8, ®);
387 return !!(reg & (1 << (led->led_num % 8)));
390 static int pca955x_gpio_direction_input(struct gpio_chip *gc,
393 struct pca955x *pca955x = gpiochip_get_data(gc);
394 struct pca955x_led *led = &pca955x->leds[offset];
396 /* To use as input ensure pin is not driven. */
397 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
400 static int pca955x_gpio_direction_output(struct gpio_chip *gc,
401 unsigned int offset, int val)
403 return pca955x_set_value(gc, offset, val);
405 #endif /* CONFIG_LEDS_PCA955X_GPIO */
407 static struct pca955x_platform_data *
408 pca955x_get_pdata(struct i2c_client *client, const struct pca955x_chipdef *chip)
410 struct pca955x_platform_data *pdata;
411 struct pca955x_led *led;
412 struct fwnode_handle *child;
415 count = device_get_child_node_count(&client->dev);
416 if (count > chip->bits)
417 return ERR_PTR(-ENODEV);
419 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
421 return ERR_PTR(-ENOMEM);
423 pdata->leds = devm_kcalloc(&client->dev,
424 chip->bits, sizeof(struct pca955x_led),
427 return ERR_PTR(-ENOMEM);
429 device_for_each_child_node(&client->dev, child) {
433 res = fwnode_property_read_u32(child, "reg", ®);
434 if ((res != 0) || (reg >= chip->bits))
437 led = &pdata->leds[reg];
438 led->type = PCA955X_TYPE_LED;
440 led->default_state = led_init_default_state_get(child);
442 fwnode_property_read_u32(child, "type", &led->type);
445 pdata->num_leds = chip->bits;
450 static int pca955x_probe(struct i2c_client *client)
452 struct pca955x *pca955x;
453 struct pca955x_led *pca955x_led;
454 const struct pca955x_chipdef *chip;
455 struct led_classdev *led;
456 struct led_init_data init_data;
457 struct i2c_adapter *adapter;
459 struct pca955x_platform_data *pdata;
460 bool set_default_label = false;
461 bool keep_pwm = false;
462 char default_label[8];
464 chip = i2c_get_match_data(client);
466 return dev_err_probe(&client->dev, -ENODEV, "unknown chip\n");
468 adapter = client->adapter;
469 pdata = dev_get_platdata(&client->dev);
471 pdata = pca955x_get_pdata(client, chip);
473 return PTR_ERR(pdata);
476 /* Make sure the slave address / chip type combo given is possible */
477 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
479 dev_err(&client->dev, "invalid slave address %02x\n",
484 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
485 "slave address 0x%02x\n", client->name, chip->bits,
488 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
491 if (pdata->num_leds != chip->bits) {
492 dev_err(&client->dev,
493 "board info claims %d LEDs on a %d-bit chip\n",
494 pdata->num_leds, chip->bits);
498 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
502 pca955x->leds = devm_kcalloc(&client->dev, chip->bits,
503 sizeof(*pca955x_led), GFP_KERNEL);
507 i2c_set_clientdata(client, pca955x);
509 mutex_init(&pca955x->lock);
510 pca955x->client = client;
511 pca955x->chipdef = chip;
513 init_data.devname_mandatory = false;
514 init_data.devicename = "pca955x";
516 for (i = 0; i < chip->bits; i++) {
517 pca955x_led = &pca955x->leds[i];
518 pca955x_led->led_num = i;
519 pca955x_led->pca955x = pca955x;
520 pca955x_led->type = pdata->leds[i].type;
522 switch (pca955x_led->type) {
523 case PCA955X_TYPE_NONE:
524 case PCA955X_TYPE_GPIO:
526 case PCA955X_TYPE_LED:
527 led = &pca955x_led->led_cdev;
528 led->brightness_set_blocking = pca955x_led_set;
529 led->brightness_get = pca955x_led_get;
531 if (pdata->leds[i].default_state == LEDS_DEFSTATE_OFF) {
532 err = pca955x_led_set(led, LED_OFF);
535 } else if (pdata->leds[i].default_state == LEDS_DEFSTATE_ON) {
536 err = pca955x_led_set(led, LED_FULL);
541 init_data.fwnode = pdata->leds[i].fwnode;
543 if (is_of_node(init_data.fwnode)) {
544 if (to_of_node(init_data.fwnode)->name[0] ==
546 set_default_label = true;
548 set_default_label = false;
550 set_default_label = true;
553 if (set_default_label) {
554 snprintf(default_label, sizeof(default_label),
556 init_data.default_label = default_label;
558 init_data.default_label = NULL;
561 err = devm_led_classdev_register_ext(&client->dev, led,
566 set_bit(i, &pca955x->active_pins);
569 * For default-state == "keep", let the core update the
570 * brightness from the hardware, then check the
571 * brightness to see if it's using PWM1. If so, PWM1
572 * should not be written below.
574 if (pdata->leds[i].default_state == LEDS_DEFSTATE_KEEP) {
575 if (led->brightness != LED_FULL &&
576 led->brightness != LED_OFF &&
577 led->brightness != LED_HALF)
583 /* PWM0 is used for half brightness or 50% duty cycle */
584 err = pca955x_write_pwm(client, 0, 255 - LED_HALF);
589 /* PWM1 is used for variable brightness, default to OFF */
590 err = pca955x_write_pwm(client, 1, 0);
595 /* Set to fast frequency so we do not see flashing */
596 err = pca955x_write_psc(client, 0, 0);
599 err = pca955x_write_psc(client, 1, 0);
603 #ifdef CONFIG_LEDS_PCA955X_GPIO
604 pca955x->gpio.label = "gpio-pca955x";
605 pca955x->gpio.direction_input = pca955x_gpio_direction_input;
606 pca955x->gpio.direction_output = pca955x_gpio_direction_output;
607 pca955x->gpio.set = pca955x_gpio_set_value;
608 pca955x->gpio.get = pca955x_gpio_get_value;
609 pca955x->gpio.request = pca955x_gpio_request_pin;
610 pca955x->gpio.free = pca955x_gpio_free_pin;
611 pca955x->gpio.can_sleep = 1;
612 pca955x->gpio.base = -1;
613 pca955x->gpio.ngpio = chip->bits;
614 pca955x->gpio.parent = &client->dev;
615 pca955x->gpio.owner = THIS_MODULE;
617 err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
620 /* Use data->gpio.dev as a flag for freeing gpiochip */
621 pca955x->gpio.parent = NULL;
622 dev_warn(&client->dev, "could not add gpiochip\n");
625 dev_info(&client->dev, "gpios %i...%i\n",
626 pca955x->gpio.base, pca955x->gpio.base +
627 pca955x->gpio.ngpio - 1);
633 static const struct i2c_device_id pca955x_id[] = {
634 { "pca9550", (kernel_ulong_t)&pca955x_chipdefs[pca9550] },
635 { "pca9551", (kernel_ulong_t)&pca955x_chipdefs[pca9551] },
636 { "pca9552", (kernel_ulong_t)&pca955x_chipdefs[pca9552] },
637 { "ibm-pca9552", (kernel_ulong_t)&pca955x_chipdefs[ibm_pca9552] },
638 { "pca9553", (kernel_ulong_t)&pca955x_chipdefs[pca9553] },
641 MODULE_DEVICE_TABLE(i2c, pca955x_id);
643 static const struct of_device_id of_pca955x_match[] = {
644 { .compatible = "nxp,pca9550", .data = &pca955x_chipdefs[pca9550] },
645 { .compatible = "nxp,pca9551", .data = &pca955x_chipdefs[pca9551] },
646 { .compatible = "nxp,pca9552", .data = &pca955x_chipdefs[pca9552] },
647 { .compatible = "ibm,pca9552", .data = &pca955x_chipdefs[ibm_pca9552] },
648 { .compatible = "nxp,pca9553", .data = &pca955x_chipdefs[pca9553] },
651 MODULE_DEVICE_TABLE(of, of_pca955x_match);
653 static struct i2c_driver pca955x_driver = {
655 .name = "leds-pca955x",
656 .of_match_table = of_pca955x_match,
658 .probe = pca955x_probe,
659 .id_table = pca955x_id,
662 module_i2c_driver(pca955x_driver);
665 MODULE_DESCRIPTION("PCA955x LED driver");
666 MODULE_LICENSE("GPL v2");