/* * Copyright 2007-2008 Extreme Engineering Solutions, Inc. * Author: Nate Case * * Copyright (C) 2018 WAGO Kontakttechnik GmbH & Co. KG * Author: Oleg Karfich * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * This code was ported from linux-4.18 kernel driver. * Orginal code with it's copyright info can be found in * drivers/leds/leds-pca955x.c * * LED driver for various PCA955x I2C LED drivers * * Supported devices: * * Device Description 7-bit slave address * ------ ----------- ------------------- * PCA9550 2-bit driver 0x60 .. 0x61 * PCA9551 8-bit driver 0x60 .. 0x67 * PCA9552 16-bit driver 0x60 .. 0x67 * PCA9553/01 4-bit driver 0x62 * PCA9553/02 4-bit driver 0x63 * * Philips PCA955x LED driver chips follow a register map as shown below: * * Control Register Description * ---------------- ----------- * 0x0 Input register 0 * .. * NUM_INPUT_REGS - 1 Last Input register X * * NUM_INPUT_REGS Frequency prescaler 0 * NUM_INPUT_REGS + 1 PWM register 0 * NUM_INPUT_REGS + 2 Frequency prescaler 1 * NUM_INPUT_REGS + 3 PWM register 1 * * NUM_INPUT_REGS + 4 LED selector 0 * NUM_INPUT_REGS + 4 * + NUM_LED_REGS - 1 Last LED selector * * where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many * bits the chip supports. * */ #include #include #include #include #include #include /* LED select registers determine the source that drives LED outputs */ #define PCA955X_LS_LED_ON 0x0 /* Output LOW */ #define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */ #define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */ #define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */ enum led_brightness { LED_OFF = 0, LED_HALF = 127, LED_FULL = 255, }; enum pca955x_type { pca9550, pca9551, pca9552, pca9553, }; struct pca955x_chipdef { int bits; u8 slv_addr; /* 7-bit slave address mask */ int slv_addr_shift; /* Number of bits to ignore */ }; static struct pca955x_chipdef pca955x_chipdefs[] = { [pca9550] = { .bits = 2, .slv_addr = /* 110000x */ 0x60, .slv_addr_shift = 1, }, [pca9551] = { .bits = 8, .slv_addr = /* 1100xxx */ 0x60, .slv_addr_shift = 3, }, [pca9552] = { .bits = 16, .slv_addr = /* 1100xxx */ 0x60, .slv_addr_shift = 3, }, [pca9553] = { .bits = 4, .slv_addr = /* 110001x */ 0x62, .slv_addr_shift = 1, }, }; static const struct platform_device_id led_pca955x_id[] = { { "pca9550", pca9550 }, { "pca9551", pca9551 }, { "pca9552", pca9552 }, { "pca9553", pca9553 }, { } }; struct pca955x { struct pca955x_led *leds; struct pca955x_chipdef *chipdef; struct i2c_client *client; }; struct pca955x_led { struct pca955x *pca955x; struct led led_cdev; int led_num; /* 0 .. 15 potentially */ char name[32]; }; struct pca955x_platform_data { struct pca955x_led *leds; int num_leds; }; /* 8 bits per input register */ static inline int pca95xx_num_input_regs(int bits) { return (bits + 7) / 8; } /* * Return an LED selector register value based on an existing one, with * the appropriate 2-bit state value set for the given LED number (0-3). */ static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state) { return (oldval & (~(0x3 << (led_num << 1)))) | ((state & 0x3) << (led_num << 1)); } /* * Write to frequency prescaler register, used to program the * period of the PWM output. period = (PSCx + 1) / 38 */ static int pca955x_write_psc(struct i2c_client *client, int n, u8 val) { struct pca955x *pca955x = i2c_get_clientdata(client); int ret; ret = i2c_smbus_write_byte_data(client, pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n, val); if (ret < 0) dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", __func__, n, val, ret); return ret; } /* * Write to PWM register, which determines the duty cycle of the * output. LED is OFF when the count is less than the value of this * register, and ON when it is greater. If PWMx == 0, LED is always OFF. * * Duty cycle is (256 - PWMx) / 256 */ static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val) { struct pca955x *pca955x = i2c_get_clientdata(client); int ret; ret = i2c_smbus_write_byte_data(client, pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n, val); if (ret < 0) dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", __func__, n, val, ret); return ret; } /* * Write to LED selector register, which determines the source that * drives the LED output. */ static int pca955x_write_ls(struct i2c_client *client, int n, u8 val) { struct pca955x *pca955x = i2c_get_clientdata(client); int ret; ret = i2c_smbus_write_byte_data(client, pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n, val); if (ret < 0) dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n", __func__, n, val, ret); return ret; } /* * Read the LED selector register, which determines the source that * drives the LED output. */ static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val) { struct pca955x *pca955x = i2c_get_clientdata(client); int ret; ret = i2c_smbus_read_byte_data(client, pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n); if (ret < 0) { dev_err(&client->dev, "%s: reg 0x%x, err %d\n", __func__, n, ret); return ret; } *val = (u8)ret; return 0; } static void pca955x_led_set(struct led *led_cdev, unsigned int value) { struct pca955x_led *pca955x_led; struct pca955x *pca955x; u8 ls; int chip_ls; /* which LSx to use (0-3 potentially) */ int ls_led; /* which set of bits within LSx to use (0-3) */ int ret; pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev); pca955x = pca955x_led->pca955x; chip_ls = pca955x_led->led_num / 4; ls_led = pca955x_led->led_num % 4; ret = pca955x_read_ls(pca955x->client, chip_ls, &ls); if (ret) return; switch (value) { case LED_FULL: ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON); break; case LED_OFF: ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF); break; case LED_HALF: ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0); break; default: /* * Use PWM1 for all other values. This has the unwanted * side effect of making all LEDs on the chip share the * same brightness level if set to a value other than * OFF, HALF, or FULL. But, this is probably better than * just turning off for all other values. */ ret = pca955x_write_pwm(pca955x->client, 1, 255 - value); if (ret) return; ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1); break; } pca955x_write_ls(pca955x->client, chip_ls, ls); } static struct pca955x_platform_data * led_pca955x_pdata_of_init(struct device_node *np, struct pca955x *pca955x) { struct device_node *child; struct pca955x_chipdef *chip = pca955x->chipdef; struct pca955x_platform_data *pdata; int count, err; count = of_get_child_count(np); if (!count || count > chip->bits) return ERR_PTR(-ENODEV); pdata = xzalloc(sizeof(*pdata)); if (!pdata) return ERR_PTR(-ENOMEM); pdata->leds = xzalloc(chip->bits * sizeof(struct pca955x_led)); if (!pdata->leds) return ERR_PTR(-ENOMEM); for_each_child_of_node(np, child) { struct pca955x_led *pca955x_led; const char *name; u32 reg; int res; res = of_property_read_u32(child, "reg", ®); if ((res != 0) || (reg >= chip->bits)) continue; pca955x_led = &pdata->leds[reg]; pca955x_led->led_num = reg; pca955x_led->pca955x = pca955x; if (of_property_read_string(child, "label", &name)) name = child->name; snprintf(pca955x_led->name, sizeof(pca955x_led->name), "%s", name); pca955x_led->led_cdev.name = pca955x_led->name; pca955x_led->led_cdev.set = pca955x_led_set; pca955x_led->led_cdev.num = pca955x_led->led_num; pca955x_led->led_cdev.max_value = 255; err = led_register(&pca955x_led->led_cdev); if (err) return ERR_PTR(err); /* Turn off LED */ pca955x_led_set(&pca955x_led->led_cdev, LED_OFF); led_of_parse_trigger(&pca955x_led->led_cdev, child); } pdata->num_leds = count; return pdata; } static const struct of_device_id of_pca955x_match[] = { { .compatible = "nxp,pca9550", .data = (void *)pca9550 }, { .compatible = "nxp,pca9551", .data = (void *)pca9551 }, { .compatible = "nxp,pca9552", .data = (void *)pca9552 }, { .compatible = "nxp,pca9553", .data = (void *)pca9553 }, {}, }; static int led_pca955x_probe(struct device_d *dev) { struct pca955x *pca955x; struct pca955x_led *pca955x_led; struct pca955x_chipdef *chip; struct i2c_client *client; int err; struct pca955x_platform_data *pdata; chip = &pca955x_chipdefs[dev->id_entry->driver_data]; client = to_i2c_client(dev); /* Make sure the slave address / chip type combo given is possible */ if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) != chip->slv_addr) { dev_err(dev, "invalid slave address %02x\n", client->addr); return -ENODEV; } dev_info(dev, "leds-pca955x: Using %s %d-bit LED driver at " "slave address 0x%02x\n", client->dev.name, chip->bits, client->addr); pca955x = xzalloc(sizeof(*pca955x)); if (!pca955x) return -ENOMEM; pca955x->leds = xzalloc(chip->bits * sizeof(*pca955x_led)); if (!pca955x->leds) return -ENOMEM; i2c_set_clientdata(client, pca955x); pca955x->client = client; pca955x->chipdef = chip; pdata = led_pca955x_pdata_of_init(dev->device_node, pca955x); if (IS_ERR(pdata)) return PTR_ERR(pdata); if (pdata->num_leds != chip->bits) dev_warn(dev, "board info claims %d LEDs on a %d-bit chip\n", pdata->num_leds, chip->bits); /* PWM0 is used for half brightness or 50% duty cycle */ err = pca955x_write_pwm(client, 0, 255 - LED_HALF); if (err) return err; /* PWM1 is used for variable brightness, default to OFF */ err = pca955x_write_pwm(client, 1, 0); if (err) return err; /* Set to fast frequency so we do not see flashing */ err = pca955x_write_psc(client, 0, 0); if (err) return err; err = pca955x_write_psc(client, 1, 0); if (err) return err; return 0; } static struct driver_d led_pca955x_driver = { .name = "led-pca955x", .probe = led_pca955x_probe, .id_table = led_pca955x_id, .of_compatible = DRV_OF_COMPAT(of_pca955x_match), }; static int __init led_pca955x_init(void) { return i2c_driver_register(&led_pca955x_driver); } device_initcall(led_pca955x_init);