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gerrit.devboardsforandroid.linaro.org / platform / external / u-boot / 891b487098ee2169a16b1bbb354aaef28aa90630 / . / drivers / misc / pca9551_led.c
blob: 79b1e20ccf1e12371d207ce6d42586d1307183d9 [file] [log] [blame]
Stefan Roese1cdd9412015-03-12 11:22:46 +0100[diff] [blame]1/*
2 * Copyright (C) 2015 Stefan Roese <sr@denx.de>
3 *
4 * SPDX-License-Identifier: GPL-2.0+
5 */
6
7#include <common.h>
8#include <errno.h>
9#include <i2c.h>
10
11#ifndef CONFIG_PCA9551_I2C_ADDR
12#error "CONFIG_PCA9551_I2C_ADDR not defined!"
13#endif
14
15#define PCA9551_REG_INPUT 0x00 /* Input register (read only) */
16#define PCA9551_REG_PSC0 0x01 /* Frequency prescaler 0 */
17#define PCA9551_REG_PWM0 0x02 /* PWM0 */
18#define PCA9551_REG_PSC1 0x03 /* Frequency prescaler 1 */
19#define PCA9551_REG_PWM1 0x04 /* PWM1 */
20#define PCA9551_REG_LS0 0x05 /* LED0 to LED3 selector */
21#define PCA9551_REG_LS1 0x06 /* LED4 to LED7 selector */
22
23#define PCA9551_CTRL_AI (1 << 4) /* Auto-increment flag */
24
25#define PCA9551_LED_STATE_ON 0x00
26#define PCA9551_LED_STATE_OFF 0x01
27#define PCA9551_LED_STATE_BLINK0 0x02
28#define PCA9551_LED_STATE_BLINK1 0x03
29
30struct pca9551_blink_rate {
31 u8 psc; /* Frequency preescaler, see PCA9551_7.pdf p. 6 */
32 u8 pwm; /* Pulse width modulation, see PCA9551_7.pdf p. 6 */
33};
34
35static int freq0, freq1;
36
37static int pca9551_led_get_state(int led, int *state)
38{
39 unsigned int reg;
40 u8 shift, buf;
41 int ret;
42
43 if (led < 0 || led > 7) {
44 return -EINVAL;
45 } else if (led < 4) {
46 reg = PCA9551_REG_LS0;
47 shift = led << 1;
48 } else {
49 reg = PCA9551_REG_LS1;
50 shift = (led - 4) << 1;
51 }
52
53 ret = i2c_read(CONFIG_PCA9551_I2C_ADDR, reg, 1, &buf, 1);
54 if (ret)
55 return ret;
56
57 *state = (buf >> shift) & 0x03;
58 return 0;
59}
60
61static int pca9551_led_set_state(int led, int state)
62{
63 unsigned int reg;
64 u8 shift, buf, mask;
65 int ret;
66
67 if (led < 0 || led > 7) {
68 return -EINVAL;
69 } else if (led < 4) {
70 reg = PCA9551_REG_LS0;
71 shift = led << 1;
72 } else {
73 reg = PCA9551_REG_LS1;
74 shift = (led - 4) << 1;
75 }
76 mask = 0x03 << shift;
77
78 ret = i2c_read(CONFIG_PCA9551_I2C_ADDR, reg, 1, &buf, 1);
79 if (ret)
80 return ret;
81
82 buf = (buf & ~mask) | ((state & 0x03) << shift);
83
84 ret = i2c_write(CONFIG_PCA9551_I2C_ADDR, reg, 1, &buf, 1);
85 if (ret)
86 return ret;
87
88 return 0;
89}
90
91static int pca9551_led_set_blink_rate(int idx, struct pca9551_blink_rate rate)
92{
93 unsigned int reg;
94 int ret;
95
96 switch (idx) {
97 case 0:
98 reg = PCA9551_REG_PSC0;
99 break;
100 case 1:
101 reg = PCA9551_REG_PSC1;
102 break;
103 default:
104 return -EINVAL;
105 }
106 reg |= PCA9551_CTRL_AI;
107
108 ret = i2c_write(CONFIG_PCA9551_I2C_ADDR, reg, 1, (u8 *)&rate, 2);
109 if (ret)
110 return ret;
111
112 return 0;
113}
114
115/*
116 * Functions referenced by cmd_led.c
117 */
118void __led_set(led_id_t mask, int state)
119{
120 if (state == STATUS_LED_OFF)
121 pca9551_led_set_state(mask, PCA9551_LED_STATE_OFF);
122 else
123 pca9551_led_set_state(mask, PCA9551_LED_STATE_ON);
124}
125
126void __led_toggle(led_id_t mask)
127{
128 int state = 0;
129
130 pca9551_led_get_state(mask, &state);
131 pca9551_led_set_state(mask, !state);
132}
133
134void __led_blink(led_id_t mask, int freq)
135{
136 struct pca9551_blink_rate rate;
137 int mode;
138 int blink;
139
140 if ((freq0 == 0) || (freq == freq0)) {
141 blink = 0;
142 mode = PCA9551_LED_STATE_BLINK0;
143 freq0 = freq;
144 } else {
145 blink = 1;
146 mode = PCA9551_LED_STATE_BLINK1;
147 freq1 = freq;
148 }
149
150 rate.psc = ((freq * 38) / 1000) - 1;
151 rate.pwm = 128; /* 50% duty cycle */
152
153 pca9551_led_set_blink_rate(blink, rate);
154 pca9551_led_set_state(mask, mode);
155}