1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright 2007-2008 Extreme Engineering Solutions, Inc.
5 * Author: Nate Case <ncase@xes-inc.com>
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 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,
107 static const struct i2c_device_id pca955x_id[] = {
108 { "pca9550", pca9550 },
109 { "pca9551", pca9551 },
110 { "pca9552", pca9552 },
111 { "ibm-pca9552", ibm_pca9552 },
112 { "pca9553", pca9553 },
115 MODULE_DEVICE_TABLE(i2c, pca955x_id);
119 struct pca955x_led *leds;
120 struct pca955x_chipdef *chipdef;
121 struct i2c_client *client;
122 unsigned long active_pins;
123 #ifdef CONFIG_LEDS_PCA955X_GPIO
124 struct gpio_chip gpio;
129 struct pca955x *pca955x;
130 struct led_classdev led_cdev;
131 int led_num; /* 0 .. 15 potentially */
134 struct fwnode_handle *fwnode;
137 struct pca955x_platform_data {
138 struct pca955x_led *leds;
142 /* 8 bits per input register */
143 static inline int pca95xx_num_input_regs(int bits)
145 return (bits + 7) / 8;
149 * Return an LED selector register value based on an existing one, with
150 * the appropriate 2-bit state value set for the given LED number (0-3).
152 static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
154 return (oldval & (~(0x3 << (led_num << 1)))) |
155 ((state & 0x3) << (led_num << 1));
159 * Write to frequency prescaler register, used to program the
160 * period of the PWM output. period = (PSCx + 1) / 38
162 static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
164 struct pca955x *pca955x = i2c_get_clientdata(client);
165 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + (2 * n);
168 ret = i2c_smbus_write_byte_data(client, cmd, val);
170 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
171 __func__, n, val, ret);
176 * Write to PWM register, which determines the duty cycle of the
177 * output. LED is OFF when the count is less than the value of this
178 * register, and ON when it is greater. If PWMx == 0, LED is always OFF.
180 * Duty cycle is (256 - PWMx) / 256
182 static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
184 struct pca955x *pca955x = i2c_get_clientdata(client);
185 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
188 ret = i2c_smbus_write_byte_data(client, cmd, val);
190 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
191 __func__, n, val, ret);
196 * Write to LED selector register, which determines the source that
197 * drives the LED output.
199 static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
201 struct pca955x *pca955x = i2c_get_clientdata(client);
202 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n;
205 ret = i2c_smbus_write_byte_data(client, cmd, val);
207 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
208 __func__, n, val, ret);
213 * Read the LED selector register, which determines the source that
214 * drives the LED output.
216 static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val)
218 struct pca955x *pca955x = i2c_get_clientdata(client);
219 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n;
222 ret = i2c_smbus_read_byte_data(client, cmd);
224 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
232 static int pca955x_read_pwm(struct i2c_client *client, int n, u8 *val)
234 struct pca955x *pca955x = i2c_get_clientdata(client);
235 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
238 ret = i2c_smbus_read_byte_data(client, cmd);
240 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
248 static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev)
250 struct pca955x_led *pca955x_led = container_of(led_cdev,
253 struct pca955x *pca955x = pca955x_led->pca955x;
257 ret = pca955x_read_ls(pca955x->client, pca955x_led->led_num / 4, &ls);
261 ls = (ls >> ((pca955x_led->led_num % 4) << 1)) & 0x3;
263 case PCA955X_LS_LED_ON:
266 case PCA955X_LS_LED_OFF:
269 case PCA955X_LS_BLINK0:
272 case PCA955X_LS_BLINK1:
273 ret = pca955x_read_pwm(pca955x->client, 1, &pwm);
283 static int pca955x_led_set(struct led_classdev *led_cdev,
284 enum led_brightness value)
286 struct pca955x_led *pca955x_led;
287 struct pca955x *pca955x;
289 int chip_ls; /* which LSx to use (0-3 potentially) */
290 int ls_led; /* which set of bits within LSx to use (0-3) */
293 pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev);
294 pca955x = pca955x_led->pca955x;
296 chip_ls = pca955x_led->led_num / 4;
297 ls_led = pca955x_led->led_num % 4;
299 mutex_lock(&pca955x->lock);
301 ret = pca955x_read_ls(pca955x->client, chip_ls, &ls);
307 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
310 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
313 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
317 * Use PWM1 for all other values. This has the unwanted
318 * side effect of making all LEDs on the chip share the
319 * same brightness level if set to a value other than
320 * OFF, HALF, or FULL. But, this is probably better than
321 * just turning off for all other values.
323 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value);
326 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
330 ret = pca955x_write_ls(pca955x->client, chip_ls, ls);
333 mutex_unlock(&pca955x->lock);
338 #ifdef CONFIG_LEDS_PCA955X_GPIO
340 * Read the INPUT register, which contains the state of LEDs.
342 static int pca955x_read_input(struct i2c_client *client, int n, u8 *val)
344 int ret = i2c_smbus_read_byte_data(client, n);
347 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
356 static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
358 struct pca955x *pca955x = gpiochip_get_data(gc);
360 return test_and_set_bit(offset, &pca955x->active_pins) ? -EBUSY : 0;
363 static void pca955x_gpio_free_pin(struct gpio_chip *gc, unsigned int offset)
365 struct pca955x *pca955x = gpiochip_get_data(gc);
367 clear_bit(offset, &pca955x->active_pins);
370 static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset,
373 struct pca955x *pca955x = gpiochip_get_data(gc);
374 struct pca955x_led *led = &pca955x->leds[offset];
377 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH);
379 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW);
382 static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
385 pca955x_set_value(gc, offset, val);
388 static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
390 struct pca955x *pca955x = gpiochip_get_data(gc);
391 struct pca955x_led *led = &pca955x->leds[offset];
394 /* There is nothing we can do about errors */
395 pca955x_read_input(pca955x->client, led->led_num / 8, ®);
397 return !!(reg & (1 << (led->led_num % 8)));
400 static int pca955x_gpio_direction_input(struct gpio_chip *gc,
403 struct pca955x *pca955x = gpiochip_get_data(gc);
404 struct pca955x_led *led = &pca955x->leds[offset];
406 /* To use as input ensure pin is not driven. */
407 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
410 static int pca955x_gpio_direction_output(struct gpio_chip *gc,
411 unsigned int offset, int val)
413 return pca955x_set_value(gc, offset, val);
415 #endif /* CONFIG_LEDS_PCA955X_GPIO */
417 static struct pca955x_platform_data *
418 pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip)
420 struct pca955x_platform_data *pdata;
421 struct pca955x_led *led;
422 struct fwnode_handle *child;
425 count = device_get_child_node_count(&client->dev);
426 if (count > chip->bits)
427 return ERR_PTR(-ENODEV);
429 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
431 return ERR_PTR(-ENOMEM);
433 pdata->leds = devm_kcalloc(&client->dev,
434 chip->bits, sizeof(struct pca955x_led),
437 return ERR_PTR(-ENOMEM);
439 device_for_each_child_node(&client->dev, child) {
444 res = fwnode_property_read_u32(child, "reg", ®);
445 if ((res != 0) || (reg >= chip->bits))
448 led = &pdata->leds[reg];
449 led->type = PCA955X_TYPE_LED;
451 fwnode_property_read_u32(child, "type", &led->type);
453 if (!fwnode_property_read_string(child, "default-state",
455 if (!strcmp(state, "keep"))
456 led->default_state = LEDS_GPIO_DEFSTATE_KEEP;
457 else if (!strcmp(state, "on"))
458 led->default_state = LEDS_GPIO_DEFSTATE_ON;
460 led->default_state = LEDS_GPIO_DEFSTATE_OFF;
462 led->default_state = LEDS_GPIO_DEFSTATE_OFF;
466 pdata->num_leds = chip->bits;
471 static const struct of_device_id of_pca955x_match[] = {
472 { .compatible = "nxp,pca9550", .data = (void *)pca9550 },
473 { .compatible = "nxp,pca9551", .data = (void *)pca9551 },
474 { .compatible = "nxp,pca9552", .data = (void *)pca9552 },
475 { .compatible = "ibm,pca9552", .data = (void *)ibm_pca9552 },
476 { .compatible = "nxp,pca9553", .data = (void *)pca9553 },
479 MODULE_DEVICE_TABLE(of, of_pca955x_match);
481 static int pca955x_probe(struct i2c_client *client)
483 struct pca955x *pca955x;
484 struct pca955x_led *pca955x_led;
485 struct pca955x_chipdef *chip;
486 struct led_classdev *led;
487 struct led_init_data init_data;
488 struct i2c_adapter *adapter;
490 struct pca955x_platform_data *pdata;
491 bool set_default_label = false;
492 bool keep_pwm = false;
493 char default_label[8];
494 enum pca955x_type chip_type;
495 const void *md = device_get_match_data(&client->dev);
498 chip_type = (enum pca955x_type)md;
500 const struct i2c_device_id *id = i2c_match_id(pca955x_id,
504 chip_type = (enum pca955x_type)id->driver_data;
506 dev_err(&client->dev, "unknown chip\n");
511 chip = &pca955x_chipdefs[chip_type];
512 adapter = client->adapter;
513 pdata = dev_get_platdata(&client->dev);
515 pdata = pca955x_get_pdata(client, chip);
517 return PTR_ERR(pdata);
520 /* Make sure the slave address / chip type combo given is possible */
521 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
523 dev_err(&client->dev, "invalid slave address %02x\n",
528 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
529 "slave address 0x%02x\n", client->name, chip->bits,
532 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
535 if (pdata->num_leds != chip->bits) {
536 dev_err(&client->dev,
537 "board info claims %d LEDs on a %d-bit chip\n",
538 pdata->num_leds, chip->bits);
542 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
546 pca955x->leds = devm_kcalloc(&client->dev, chip->bits,
547 sizeof(*pca955x_led), GFP_KERNEL);
551 i2c_set_clientdata(client, pca955x);
553 mutex_init(&pca955x->lock);
554 pca955x->client = client;
555 pca955x->chipdef = chip;
557 init_data.devname_mandatory = false;
558 init_data.devicename = "pca955x";
560 for (i = 0; i < chip->bits; i++) {
561 pca955x_led = &pca955x->leds[i];
562 pca955x_led->led_num = i;
563 pca955x_led->pca955x = pca955x;
564 pca955x_led->type = pdata->leds[i].type;
566 switch (pca955x_led->type) {
567 case PCA955X_TYPE_NONE:
568 case PCA955X_TYPE_GPIO:
570 case PCA955X_TYPE_LED:
571 led = &pca955x_led->led_cdev;
572 led->brightness_set_blocking = pca955x_led_set;
573 led->brightness_get = pca955x_led_get;
575 if (pdata->leds[i].default_state ==
576 LEDS_GPIO_DEFSTATE_OFF) {
577 err = pca955x_led_set(led, LED_OFF);
580 } else if (pdata->leds[i].default_state ==
581 LEDS_GPIO_DEFSTATE_ON) {
582 err = pca955x_led_set(led, LED_FULL);
587 init_data.fwnode = pdata->leds[i].fwnode;
589 if (is_of_node(init_data.fwnode)) {
590 if (to_of_node(init_data.fwnode)->name[0] ==
592 set_default_label = true;
594 set_default_label = false;
596 set_default_label = true;
599 if (set_default_label) {
600 snprintf(default_label, sizeof(default_label),
602 init_data.default_label = default_label;
604 init_data.default_label = NULL;
607 err = devm_led_classdev_register_ext(&client->dev, led,
612 set_bit(i, &pca955x->active_pins);
615 * For default-state == "keep", let the core update the
616 * brightness from the hardware, then check the
617 * brightness to see if it's using PWM1. If so, PWM1
618 * should not be written below.
620 if (pdata->leds[i].default_state ==
621 LEDS_GPIO_DEFSTATE_KEEP) {
622 if (led->brightness != LED_FULL &&
623 led->brightness != LED_OFF &&
624 led->brightness != LED_HALF)
630 /* PWM0 is used for half brightness or 50% duty cycle */
631 err = pca955x_write_pwm(client, 0, 255 - LED_HALF);
636 /* PWM1 is used for variable brightness, default to OFF */
637 err = pca955x_write_pwm(client, 1, 0);
642 /* Set to fast frequency so we do not see flashing */
643 err = pca955x_write_psc(client, 0, 0);
646 err = pca955x_write_psc(client, 1, 0);
650 #ifdef CONFIG_LEDS_PCA955X_GPIO
651 pca955x->gpio.label = "gpio-pca955x";
652 pca955x->gpio.direction_input = pca955x_gpio_direction_input;
653 pca955x->gpio.direction_output = pca955x_gpio_direction_output;
654 pca955x->gpio.set = pca955x_gpio_set_value;
655 pca955x->gpio.get = pca955x_gpio_get_value;
656 pca955x->gpio.request = pca955x_gpio_request_pin;
657 pca955x->gpio.free = pca955x_gpio_free_pin;
658 pca955x->gpio.can_sleep = 1;
659 pca955x->gpio.base = -1;
660 pca955x->gpio.ngpio = chip->bits;
661 pca955x->gpio.parent = &client->dev;
662 pca955x->gpio.owner = THIS_MODULE;
664 err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
667 /* Use data->gpio.dev as a flag for freeing gpiochip */
668 pca955x->gpio.parent = NULL;
669 dev_warn(&client->dev, "could not add gpiochip\n");
672 dev_info(&client->dev, "gpios %i...%i\n",
673 pca955x->gpio.base, pca955x->gpio.base +
674 pca955x->gpio.ngpio - 1);
680 static struct i2c_driver pca955x_driver = {
682 .name = "leds-pca955x",
683 .of_match_table = of_pca955x_match,
685 .probe_new = pca955x_probe,
686 .id_table = pca955x_id,
689 module_i2c_driver(pca955x_driver);
691 MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
692 MODULE_DESCRIPTION("PCA955x LED driver");
693 MODULE_LICENSE("GPL v2");