585 lines
15 KiB
C
585 lines
15 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright 2007-2008 Extreme Engineering Solutions, Inc.
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*
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* Author: Nate Case <ncase@xes-inc.com>
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*
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* LED driver for various PCA955x I2C LED drivers
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*
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* Supported devices:
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*
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* Device Description 7-bit slave address
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* ------ ----------- -------------------
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* PCA9550 2-bit driver 0x60 .. 0x61
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* PCA9551 8-bit driver 0x60 .. 0x67
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* PCA9552 16-bit driver 0x60 .. 0x67
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* PCA9553/01 4-bit driver 0x62
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* PCA9553/02 4-bit driver 0x63
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*
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* Philips PCA955x LED driver chips follow a register map as shown below:
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*
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* Control Register Description
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* ---------------- -----------
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* 0x0 Input register 0
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* ..
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* NUM_INPUT_REGS - 1 Last Input register X
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*
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* NUM_INPUT_REGS Frequency prescaler 0
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* NUM_INPUT_REGS + 1 PWM register 0
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* NUM_INPUT_REGS + 2 Frequency prescaler 1
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* NUM_INPUT_REGS + 3 PWM register 1
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*
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* NUM_INPUT_REGS + 4 LED selector 0
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* NUM_INPUT_REGS + 4
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* + NUM_LED_REGS - 1 Last LED selector
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*
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* where NUM_INPUT_REGS and NUM_LED_REGS vary depending on how many
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* bits the chip supports.
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*/
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#include <linux/ctype.h>
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/gpio.h>
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#include <linux/i2c.h>
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#include <linux/leds.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/property.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <dt-bindings/leds/leds-pca955x.h>
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/* LED select registers determine the source that drives LED outputs */
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#define PCA955X_LS_LED_ON 0x0 /* Output LOW */
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#define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */
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#define PCA955X_LS_BLINK0 0x2 /* Blink at PWM0 rate */
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#define PCA955X_LS_BLINK1 0x3 /* Blink at PWM1 rate */
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#define PCA955X_GPIO_INPUT LED_OFF
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#define PCA955X_GPIO_HIGH LED_OFF
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#define PCA955X_GPIO_LOW LED_FULL
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enum pca955x_type {
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pca9550,
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pca9551,
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pca9552,
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pca9553,
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};
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struct pca955x_chipdef {
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int bits;
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u8 slv_addr; /* 7-bit slave address mask */
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int slv_addr_shift; /* Number of bits to ignore */
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};
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static struct pca955x_chipdef pca955x_chipdefs[] = {
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[pca9550] = {
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.bits = 2,
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.slv_addr = /* 110000x */ 0x60,
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.slv_addr_shift = 1,
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},
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[pca9551] = {
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.bits = 8,
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.slv_addr = /* 1100xxx */ 0x60,
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.slv_addr_shift = 3,
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},
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[pca9552] = {
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.bits = 16,
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.slv_addr = /* 1100xxx */ 0x60,
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.slv_addr_shift = 3,
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},
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[pca9553] = {
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.bits = 4,
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.slv_addr = /* 110001x */ 0x62,
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.slv_addr_shift = 1,
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},
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};
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static const struct i2c_device_id pca955x_id[] = {
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{ "pca9550", pca9550 },
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{ "pca9551", pca9551 },
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{ "pca9552", pca9552 },
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{ "pca9553", pca9553 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, pca955x_id);
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struct pca955x {
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struct mutex lock;
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struct pca955x_led *leds;
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struct pca955x_chipdef *chipdef;
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struct i2c_client *client;
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#ifdef CONFIG_LEDS_PCA955X_GPIO
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struct gpio_chip gpio;
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#endif
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};
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struct pca955x_led {
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struct pca955x *pca955x;
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struct led_classdev led_cdev;
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int led_num; /* 0 .. 15 potentially */
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char name[32];
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u32 type;
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const char *default_trigger;
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};
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struct pca955x_platform_data {
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struct pca955x_led *leds;
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int num_leds;
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};
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/* 8 bits per input register */
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static inline int pca95xx_num_input_regs(int bits)
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{
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return (bits + 7) / 8;
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}
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/* 4 bits per LED selector register */
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static inline int pca95xx_num_led_regs(int bits)
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{
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return (bits + 3) / 4;
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}
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/*
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* Return an LED selector register value based on an existing one, with
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* the appropriate 2-bit state value set for the given LED number (0-3).
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*/
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static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
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{
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return (oldval & (~(0x3 << (led_num << 1)))) |
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((state & 0x3) << (led_num << 1));
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}
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/*
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* Write to frequency prescaler register, used to program the
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* period of the PWM output. period = (PSCx + 1) / 38
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*/
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static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
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{
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struct pca955x *pca955x = i2c_get_clientdata(client);
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int ret;
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ret = i2c_smbus_write_byte_data(client,
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pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n,
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val);
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if (ret < 0)
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dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
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__func__, n, val, ret);
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return ret;
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}
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/*
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* Write to PWM register, which determines the duty cycle of the
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* output. LED is OFF when the count is less than the value of this
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* register, and ON when it is greater. If PWMx == 0, LED is always OFF.
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*
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* Duty cycle is (256 - PWMx) / 256
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*/
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static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
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{
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struct pca955x *pca955x = i2c_get_clientdata(client);
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int ret;
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ret = i2c_smbus_write_byte_data(client,
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pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n,
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val);
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if (ret < 0)
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dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
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__func__, n, val, ret);
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return ret;
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}
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/*
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* Write to LED selector register, which determines the source that
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* drives the LED output.
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*/
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static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
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{
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struct pca955x *pca955x = i2c_get_clientdata(client);
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int ret;
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ret = i2c_smbus_write_byte_data(client,
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pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n,
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val);
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if (ret < 0)
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dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
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__func__, n, val, ret);
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return ret;
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}
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/*
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* Read the LED selector register, which determines the source that
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* drives the LED output.
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*/
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static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val)
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{
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struct pca955x *pca955x = i2c_get_clientdata(client);
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int ret;
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ret = i2c_smbus_read_byte_data(client,
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pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n);
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if (ret < 0) {
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dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
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__func__, n, ret);
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return ret;
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}
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*val = (u8)ret;
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return 0;
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}
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static int pca955x_led_set(struct led_classdev *led_cdev,
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enum led_brightness value)
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{
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struct pca955x_led *pca955x_led;
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struct pca955x *pca955x;
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u8 ls;
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int chip_ls; /* which LSx to use (0-3 potentially) */
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int ls_led; /* which set of bits within LSx to use (0-3) */
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int ret;
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pca955x_led = container_of(led_cdev, struct pca955x_led, led_cdev);
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pca955x = pca955x_led->pca955x;
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chip_ls = pca955x_led->led_num / 4;
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ls_led = pca955x_led->led_num % 4;
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mutex_lock(&pca955x->lock);
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ret = pca955x_read_ls(pca955x->client, chip_ls, &ls);
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if (ret)
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goto out;
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switch (value) {
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case LED_FULL:
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ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_ON);
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break;
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case LED_OFF:
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ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_LED_OFF);
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break;
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case LED_HALF:
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ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK0);
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break;
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default:
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/*
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* Use PWM1 for all other values. This has the unwanted
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* side effect of making all LEDs on the chip share the
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* same brightness level if set to a value other than
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* OFF, HALF, or FULL. But, this is probably better than
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* just turning off for all other values.
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*/
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ret = pca955x_write_pwm(pca955x->client, 1, 255 - value);
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if (ret)
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goto out;
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ls = pca955x_ledsel(ls, ls_led, PCA955X_LS_BLINK1);
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break;
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}
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ret = pca955x_write_ls(pca955x->client, chip_ls, ls);
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out:
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mutex_unlock(&pca955x->lock);
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return ret;
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}
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#ifdef CONFIG_LEDS_PCA955X_GPIO
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/*
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* Read the INPUT register, which contains the state of LEDs.
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*/
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static int pca955x_read_input(struct i2c_client *client, int n, u8 *val)
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{
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int ret = i2c_smbus_read_byte_data(client, n);
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if (ret < 0) {
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dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
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__func__, n, ret);
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return ret;
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}
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*val = (u8)ret;
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return 0;
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}
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static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
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{
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struct pca955x *pca955x = gpiochip_get_data(gc);
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struct pca955x_led *led = &pca955x->leds[offset];
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if (led->type == PCA955X_TYPE_GPIO)
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return 0;
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return -EBUSY;
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}
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static int pca955x_set_value(struct gpio_chip *gc, unsigned int offset,
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int val)
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{
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struct pca955x *pca955x = gpiochip_get_data(gc);
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struct pca955x_led *led = &pca955x->leds[offset];
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if (val)
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return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_HIGH);
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return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_LOW);
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}
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static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
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int val)
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{
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pca955x_set_value(gc, offset, val);
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}
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static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
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{
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struct pca955x *pca955x = gpiochip_get_data(gc);
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struct pca955x_led *led = &pca955x->leds[offset];
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u8 reg = 0;
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/* There is nothing we can do about errors */
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pca955x_read_input(pca955x->client, led->led_num / 8, ®);
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return !!(reg & (1 << (led->led_num % 8)));
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}
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static int pca955x_gpio_direction_input(struct gpio_chip *gc,
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unsigned int offset)
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{
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struct pca955x *pca955x = gpiochip_get_data(gc);
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struct pca955x_led *led = &pca955x->leds[offset];
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/* To use as input ensure pin is not driven. */
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return pca955x_led_set(&led->led_cdev, PCA955X_GPIO_INPUT);
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}
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static int pca955x_gpio_direction_output(struct gpio_chip *gc,
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unsigned int offset, int val)
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{
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return pca955x_set_value(gc, offset, val);
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}
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#endif /* CONFIG_LEDS_PCA955X_GPIO */
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static struct pca955x_platform_data *
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pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip)
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{
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struct pca955x_platform_data *pdata;
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struct fwnode_handle *child;
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int count;
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count = device_get_child_node_count(&client->dev);
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if (!count || count > chip->bits)
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return ERR_PTR(-ENODEV);
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pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
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if (!pdata)
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return ERR_PTR(-ENOMEM);
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pdata->leds = devm_kcalloc(&client->dev,
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chip->bits, sizeof(struct pca955x_led),
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GFP_KERNEL);
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if (!pdata->leds)
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return ERR_PTR(-ENOMEM);
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device_for_each_child_node(&client->dev, child) {
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const char *name;
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u32 reg;
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int res;
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res = fwnode_property_read_u32(child, "reg", ®);
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if ((res != 0) || (reg >= chip->bits))
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continue;
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res = fwnode_property_read_string(child, "label", &name);
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if ((res != 0) && is_of_node(child))
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name = to_of_node(child)->name;
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snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name),
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"%s", name);
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pdata->leds[reg].type = PCA955X_TYPE_LED;
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fwnode_property_read_u32(child, "type", &pdata->leds[reg].type);
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fwnode_property_read_string(child, "linux,default-trigger",
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&pdata->leds[reg].default_trigger);
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}
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pdata->num_leds = chip->bits;
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return pdata;
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}
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static const struct of_device_id of_pca955x_match[] = {
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{ .compatible = "nxp,pca9550", .data = (void *)pca9550 },
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{ .compatible = "nxp,pca9551", .data = (void *)pca9551 },
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{ .compatible = "nxp,pca9552", .data = (void *)pca9552 },
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{ .compatible = "nxp,pca9553", .data = (void *)pca9553 },
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{},
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};
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MODULE_DEVICE_TABLE(of, of_pca955x_match);
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static int pca955x_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct pca955x *pca955x;
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struct pca955x_led *pca955x_led;
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struct pca955x_chipdef *chip;
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struct i2c_adapter *adapter;
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int i, err;
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struct pca955x_platform_data *pdata;
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int ngpios = 0;
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chip = &pca955x_chipdefs[id->driver_data];
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adapter = to_i2c_adapter(client->dev.parent);
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pdata = dev_get_platdata(&client->dev);
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if (!pdata) {
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pdata = pca955x_get_pdata(client, chip);
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if (IS_ERR(pdata))
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return PTR_ERR(pdata);
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}
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/* Make sure the slave address / chip type combo given is possible */
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if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
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chip->slv_addr) {
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dev_err(&client->dev, "invalid slave address %02x\n",
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client->addr);
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return -ENODEV;
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}
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dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
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"slave address 0x%02x\n",
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client->name, chip->bits, client->addr);
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if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
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return -EIO;
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if (pdata->num_leds != chip->bits) {
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dev_err(&client->dev,
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"board info claims %d LEDs on a %d-bit chip\n",
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pdata->num_leds, chip->bits);
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return -ENODEV;
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}
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pca955x = devm_kzalloc(&client->dev, sizeof(*pca955x), GFP_KERNEL);
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if (!pca955x)
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return -ENOMEM;
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pca955x->leds = devm_kcalloc(&client->dev,
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chip->bits, sizeof(*pca955x_led), GFP_KERNEL);
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if (!pca955x->leds)
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return -ENOMEM;
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i2c_set_clientdata(client, pca955x);
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mutex_init(&pca955x->lock);
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pca955x->client = client;
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pca955x->chipdef = chip;
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for (i = 0; i < chip->bits; i++) {
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pca955x_led = &pca955x->leds[i];
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pca955x_led->led_num = i;
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pca955x_led->pca955x = pca955x;
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pca955x_led->type = pdata->leds[i].type;
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switch (pca955x_led->type) {
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case PCA955X_TYPE_NONE:
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break;
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case PCA955X_TYPE_GPIO:
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ngpios++;
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break;
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case PCA955X_TYPE_LED:
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/*
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* Platform data can specify LED names and
|
|
* default triggers
|
|
*/
|
|
if (pdata->leds[i].name[0] == '\0')
|
|
snprintf(pdata->leds[i].name,
|
|
sizeof(pdata->leds[i].name), "%d", i);
|
|
|
|
snprintf(pca955x_led->name,
|
|
sizeof(pca955x_led->name), "pca955x:%s",
|
|
pdata->leds[i].name);
|
|
|
|
if (pdata->leds[i].default_trigger)
|
|
pca955x_led->led_cdev.default_trigger =
|
|
pdata->leds[i].default_trigger;
|
|
|
|
pca955x_led->led_cdev.name = pca955x_led->name;
|
|
pca955x_led->led_cdev.brightness_set_blocking =
|
|
pca955x_led_set;
|
|
|
|
err = devm_led_classdev_register(&client->dev,
|
|
&pca955x_led->led_cdev);
|
|
if (err)
|
|
return err;
|
|
|
|
/* Turn off LED */
|
|
err = pca955x_led_set(&pca955x_led->led_cdev, LED_OFF);
|
|
if (err)
|
|
return err;
|
|
}
|
|
}
|
|
|
|
/* 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;
|
|
|
|
#ifdef CONFIG_LEDS_PCA955X_GPIO
|
|
if (ngpios) {
|
|
pca955x->gpio.label = "gpio-pca955x";
|
|
pca955x->gpio.direction_input = pca955x_gpio_direction_input;
|
|
pca955x->gpio.direction_output = pca955x_gpio_direction_output;
|
|
pca955x->gpio.set = pca955x_gpio_set_value;
|
|
pca955x->gpio.get = pca955x_gpio_get_value;
|
|
pca955x->gpio.request = pca955x_gpio_request_pin;
|
|
pca955x->gpio.can_sleep = 1;
|
|
pca955x->gpio.base = -1;
|
|
pca955x->gpio.ngpio = ngpios;
|
|
pca955x->gpio.parent = &client->dev;
|
|
pca955x->gpio.owner = THIS_MODULE;
|
|
|
|
err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
|
|
pca955x);
|
|
if (err) {
|
|
/* Use data->gpio.dev as a flag for freeing gpiochip */
|
|
pca955x->gpio.parent = NULL;
|
|
dev_warn(&client->dev, "could not add gpiochip\n");
|
|
return err;
|
|
}
|
|
dev_info(&client->dev, "gpios %i...%i\n",
|
|
pca955x->gpio.base, pca955x->gpio.base +
|
|
pca955x->gpio.ngpio - 1);
|
|
}
|
|
#endif
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct i2c_driver pca955x_driver = {
|
|
.driver = {
|
|
.name = "leds-pca955x",
|
|
.of_match_table = of_pca955x_match,
|
|
},
|
|
.probe = pca955x_probe,
|
|
.id_table = pca955x_id,
|
|
};
|
|
|
|
module_i2c_driver(pca955x_driver);
|
|
|
|
MODULE_AUTHOR("Nate Case <ncase@xes-inc.com>");
|
|
MODULE_DESCRIPTION("PCA955x LED driver");
|
|
MODULE_LICENSE("GPL v2");
|