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;
148 /* 4 bits per LED selector register */
149 static inline int pca95xx_num_led_regs(int bits)
151 return (bits + 3) / 4;
155 * Return an LED selector register value based on an existing one, with
156 * the appropriate 2-bit state value set for the given LED number (0-3).
158 static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
160 return (oldval & (~(0x3 << (led_num << 1)))) |
161 ((state & 0x3) << (led_num << 1));
165 * Write to frequency prescaler register, used to program the
166 * period of the PWM output. period = (PSCx + 1) / 38
168 static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
170 struct pca955x *pca955x = i2c_get_clientdata(client);
171 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + (2 * n);
174 ret = i2c_smbus_write_byte_data(client, cmd, val);
176 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
177 __func__, n, val, ret);
182 * Write to PWM register, which determines the duty cycle of the
183 * output. LED is OFF when the count is less than the value of this
184 * register, and ON when it is greater. If PWMx == 0, LED is always OFF.
186 * Duty cycle is (256 - PWMx) / 256
188 static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
190 struct pca955x *pca955x = i2c_get_clientdata(client);
191 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
194 ret = i2c_smbus_write_byte_data(client, cmd, val);
196 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
197 __func__, n, val, ret);
202 * Write to LED selector register, which determines the source that
203 * drives the LED output.
205 static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
207 struct pca955x *pca955x = i2c_get_clientdata(client);
208 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n;
211 ret = i2c_smbus_write_byte_data(client, cmd, val);
213 dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
214 __func__, n, val, ret);
219 * Read the LED selector register, which determines the source that
220 * drives the LED output.
222 static int pca955x_read_ls(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) + 4 + n;
228 ret = i2c_smbus_read_byte_data(client, cmd);
230 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
238 static int pca955x_read_pwm(struct i2c_client *client, int n, u8 *val)
240 struct pca955x *pca955x = i2c_get_clientdata(client);
241 u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
244 ret = i2c_smbus_read_byte_data(client, cmd);
246 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
254 static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev)
256 struct pca955x_led *pca955x_led = container_of(led_cdev,
259 struct pca955x *pca955x = pca955x_led->pca955x;
263 ret = pca955x_read_ls(pca955x->client, pca955x_led->led_num / 4, &ls);
267 ls = (ls >> ((pca955x_led->led_num % 4) << 1)) & 0x3;
269 case PCA955X_LS_LED_ON:
272 case PCA955X_LS_LED_OFF:
275 case PCA955X_LS_BLINK0:
278 case PCA955X_LS_BLINK1:
279 ret = pca955x_read_pwm(pca955x->client, 1, &pwm);
289 static int pca955x_led_set(struct led_classdev *led_cdev,
290 enum led_brightness value)
292 struct pca955x_led *pca955x_led;
293 struct pca955x *pca955x;
295 int chip_ls; /* which LSx to use (0-3 potentially) */
296 int ls_led; /* which set of bits within LSx to use (0-3) */
299 pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev);
300 pca955x = pca955x_led->pca955x;
302 chip_ls = pca955x_led->led_num / 4;
303 ls_led = pca955x_led->led_num % 4;
305 mutex_lock(&pca955x->lock);
307 ret = pca955x_read_ls(pca955x->client, chip_ls, &ls);
313 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
316 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
319 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
323 * Use PWM1 for all other values. This has the unwanted
324 * side effect of making all LEDs on the chip share the
325 * same brightness level if set to a value other than
326 * OFF, HALF, or FULL. But, this is probably better than
327 * just turning off for all other values.
329 ret = pca955x_write_pwm(pca955x->client, 1, 255 - value);
332 ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
336 ret = pca955x_write_ls(pca955x->client, chip_ls, ls);
339 mutex_unlock(&pca955x->lock);
344 #ifdef CONFIG_LEDS_PCA955X_GPIO
346 * Read the INPUT register, which contains the state of LEDs.
348 static int pca955x_read_input(struct i2c_client *client, int n, u8 *val)
350 int ret = i2c_smbus_read_byte_data(client, n);
353 dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
362 static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
364 struct pca955x *pca955x = gpiochip_get_data(gc);
366 return test_and_set_bit(offset, &pca955x->active_pins) ? -EBUSY : 0;
369 static void pca955x_gpio_free_pin(struct gpio_chip *gc, unsigned int offset)
371 struct pca955x *pca955x = gpiochip_get_data(gc);
373 clear_bit(offset, &pca955x->active_pins);
376 static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset,
379 struct pca955x *pca955x = gpiochip_get_data(gc);
380 struct pca955x_led *led = &pca955x->leds[offset];
383 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH);
385 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW);
388 static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
391 pca955x_set_value(gc, offset, val);
394 static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
396 struct pca955x *pca955x = gpiochip_get_data(gc);
397 struct pca955x_led *led = &pca955x->leds[offset];
400 /* There is nothing we can do about errors */
401 pca955x_read_input(pca955x->client, led->led_num / 8, ®);
403 return !!(reg & (1 << (led->led_num % 8)));
406 static int pca955x_gpio_direction_input(struct gpio_chip *gc,
409 struct pca955x *pca955x = gpiochip_get_data(gc);
410 struct pca955x_led *led = &pca955x->leds[offset];
412 /* To use as input ensure pin is not driven. */
413 return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
416 static int pca955x_gpio_direction_output(struct gpio_chip *gc,
417 unsigned int offset, int val)
419 return pca955x_set_value(gc, offset, val);
421 #endif /* CONFIG_LEDS_PCA955X_GPIO */
423 static struct pca955x_platform_data *
424 pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip)
426 struct pca955x_platform_data *pdata;
427 struct pca955x_led *led;
428 struct fwnode_handle *child;
431 count = device_get_child_node_count(&client->dev);
432 if (count > chip->bits)
433 return ERR_PTR(-ENODEV);
435 pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
437 return ERR_PTR(-ENOMEM);
439 pdata->leds = devm_kcalloc(&client->dev,
440 chip->bits, sizeof(struct pca955x_led),
443 return ERR_PTR(-ENOMEM);
445 device_for_each_child_node(&client->dev, child) {
450 res = fwnode_property_read_u32(child, "reg", ®);
451 if ((res != 0) || (reg >= chip->bits))
454 led = &pdata->leds[reg];
455 led->type = PCA955X_TYPE_LED;
457 fwnode_property_read_u32(child, "type", &led->type);
459 if (!fwnode_property_read_string(child, "default-state",
461 if (!strcmp(state, "keep"))
462 led->default_state = LEDS_GPIO_DEFSTATE_KEEP;
463 else if (!strcmp(state, "on"))
464 led->default_state = LEDS_GPIO_DEFSTATE_ON;
466 led->default_state = LEDS_GPIO_DEFSTATE_OFF;
468 led->default_state = LEDS_GPIO_DEFSTATE_OFF;
472 pdata->num_leds = chip->bits;
477 static const struct of_device_id of_pca955x_match[] = {
478 { .compatible = "nxp,pca9550", .data = (void *)pca9550 },
479 { .compatible = "nxp,pca9551", .data = (void *)pca9551 },
480 { .compatible = "nxp,pca9552", .data = (void *)pca9552 },
481 { .compatible = "ibm,pca9552", .data = (void *)ibm_pca9552 },
482 { .compatible = "nxp,pca9553", .data = (void *)pca9553 },
485 MODULE_DEVICE_TABLE(of, of_pca955x_match);
487 static int pca955x_probe(struct i2c_client *client)
489 struct pca955x *pca955x;
490 struct pca955x_led *pca955x_led;
491 struct pca955x_chipdef *chip;
492 struct led_classdev *led;
493 struct led_init_data init_data;
494 struct i2c_adapter *adapter;
496 struct pca955x_platform_data *pdata;
497 bool set_default_label = false;
498 bool keep_pwm = false;
499 char default_label[8];
500 enum pca955x_type chip_type;
501 const void *md = device_get_match_data(&client->dev);
504 chip_type = (enum pca955x_type)md;
506 const struct i2c_device_id *id = i2c_match_id(pca955x_id,
510 chip_type = (enum pca955x_type)id->driver_data;
512 dev_err(&client->dev, "unknown chip\n");
517 chip = &pca955x_chipdefs[chip_type];
518 adapter = client->adapter;
519 pdata = dev_get_platdata(&client->dev);
521 pdata = pca955x_get_pdata(client, chip);
523 return PTR_ERR(pdata);
526 /* Make sure the slave address / chip type combo given is possible */
527 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
529 dev_err(&client->dev, "invalid slave address %02x\n",
534 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
535 "slave address 0x%02x\n", client->name, chip->bits,
538 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
541 if (pdata->num_leds != chip->bits) {
542 dev_err(&client->dev,
543 "board info claims %d LEDs on a %d-bit chip\n",
544 pdata->num_leds, chip->bits);
548 pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
552 pca955x->leds = devm_kcalloc(&client->dev, chip->bits,
553 sizeof(*pca955x_led), GFP_KERNEL);
557 i2c_set_clientdata(client, pca955x);
559 mutex_init(&pca955x->lock);
560 pca955x->client = client;
561 pca955x->chipdef = chip;
563 init_data.devname_mandatory = false;
564 init_data.devicename = "pca955x";
566 for (i = 0; i < chip->bits; i++) {
567 pca955x_led = &pca955x->leds[i];
568 pca955x_led->led_num = i;
569 pca955x_led->pca955x = pca955x;
570 pca955x_led->type = pdata->leds[i].type;
572 switch (pca955x_led->type) {
573 case PCA955X_TYPE_NONE:
574 case PCA955X_TYPE_GPIO:
576 case PCA955X_TYPE_LED:
577 led = &pca955x_led->led_cdev;
578 led->brightness_set_blocking = pca955x_led_set;
579 led->brightness_get = pca955x_led_get;
581 if (pdata->leds[i].default_state ==
582 LEDS_GPIO_DEFSTATE_OFF) {
583 err = pca955x_led_set(led, LED_OFF);
586 } else if (pdata->leds[i].default_state ==
587 LEDS_GPIO_DEFSTATE_ON) {
588 err = pca955x_led_set(led, LED_FULL);
593 init_data.fwnode = pdata->leds[i].fwnode;
595 if (is_of_node(init_data.fwnode)) {
596 if (to_of_node(init_data.fwnode)->name[0] ==
598 set_default_label = true;
600 set_default_label = false;
602 set_default_label = true;
605 if (set_default_label) {
606 snprintf(default_label, sizeof(default_label),
608 init_data.default_label = default_label;
610 init_data.default_label = NULL;
613 err = devm_led_classdev_register_ext(&client->dev, led,
618 set_bit(i, &pca955x->active_pins);
621 * For default-state == "keep", let the core update the
622 * brightness from the hardware, then check the
623 * brightness to see if it's using PWM1. If so, PWM1
624 * should not be written below.
626 if (pdata->leds[i].default_state ==
627 LEDS_GPIO_DEFSTATE_KEEP) {
628 if (led->brightness != LED_FULL &&
629 led->brightness != LED_OFF &&
630 led->brightness != LED_HALF)
636 /* PWM0 is used for half brightness or 50% duty cycle */
637 err = pca955x_write_pwm(client, 0, 255 - LED_HALF);
642 /* PWM1 is used for variable brightness, default to OFF */
643 err = pca955x_write_pwm(client, 1, 0);
648 /* Set to fast frequency so we do not see flashing */
649 err = pca955x_write_psc(client, 0, 0);
652 err = pca955x_write_psc(client, 1, 0);
656 #ifdef CONFIG_LEDS_PCA955X_GPIO
657 pca955x->gpio.label = "gpio-pca955x";
658 pca955x->gpio.direction_input = pca955x_gpio_direction_input;
659 pca955x->gpio.direction_output = pca955x_gpio_direction_output;
660 pca955x->gpio.set = pca955x_gpio_set_value;
661 pca955x->gpio.get = pca955x_gpio_get_value;
662 pca955x->gpio.request = pca955x_gpio_request_pin;
663 pca955x->gpio.free = pca955x_gpio_free_pin;
664 pca955x->gpio.can_sleep = 1;
665 pca955x->gpio.base = -1;
666 pca955x->gpio.ngpio = chip->bits;
667 pca955x->gpio.parent = &client->dev;
668 pca955x->gpio.owner = THIS_MODULE;
670 err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
673 /* Use data->gpio.dev as a flag for freeing gpiochip */
674 pca955x->gpio.parent = NULL;
675 dev_warn(&client->dev, "could not add gpiochip\n");
678 dev_info(&client->dev, "gpios %i...%i\n",
679 pca955x->gpio.base, pca955x->gpio.base +
680 pca955x->gpio.ngpio - 1);
686 static struct i2c_driver pca955x_driver = {
688 .name = "leds-pca955x",
689 .of_match_table = of_pca955x_match,
691 .probe_new = pca955x_probe,
692 .id_table = pca955x_id,
695 module_i2c_driver(pca955x_driver);
697 MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
698 MODULE_DESCRIPTION("PCA955x LED driver");
699 MODULE_LICENSE("GPL v2");