xref: /openbmc/u-boot/drivers/misc/pca9551_led.c (revision dd1033e4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2015 Stefan Roese <sr@denx.de>
4  */
5 
6 #include <common.h>
7 #include <errno.h>
8 #include <i2c.h>
9 
10 #ifndef CONFIG_PCA9551_I2C_ADDR
11 #error "CONFIG_PCA9551_I2C_ADDR not defined!"
12 #endif
13 
14 #define PCA9551_REG_INPUT	0x00	/* Input register (read only) */
15 #define PCA9551_REG_PSC0	0x01	/* Frequency prescaler 0 */
16 #define PCA9551_REG_PWM0	0x02	/* PWM0 */
17 #define PCA9551_REG_PSC1	0x03	/* Frequency prescaler 1 */
18 #define PCA9551_REG_PWM1	0x04	/* PWM1 */
19 #define PCA9551_REG_LS0		0x05	/* LED0 to LED3 selector */
20 #define PCA9551_REG_LS1		0x06	/* LED4 to LED7 selector */
21 
22 #define PCA9551_CTRL_AI		(1 << 4)	/* Auto-increment flag */
23 
24 #define PCA9551_LED_STATE_ON		0x00
25 #define PCA9551_LED_STATE_OFF		0x01
26 #define PCA9551_LED_STATE_BLINK0	0x02
27 #define PCA9551_LED_STATE_BLINK1	0x03
28 
29 struct pca9551_blink_rate {
30 	u8 psc;	/* Frequency preescaler, see PCA9551_7.pdf p. 6 */
31 	u8 pwm;	/* Pulse width modulation, see PCA9551_7.pdf p. 6 */
32 };
33 
34 static int freq_last = -1;
35 static int mask_last = -1;
36 static int idx_last = -1;
37 static int mode_last;
38 
39 static int pca9551_led_get_state(int led, int *state)
40 {
41 	unsigned int reg;
42 	u8 shift, buf;
43 	int ret;
44 
45 	if (led < 0 || led > 7) {
46 		return -EINVAL;
47 	} else if (led < 4) {
48 		reg = PCA9551_REG_LS0;
49 		shift = led << 1;
50 	} else {
51 		reg = PCA9551_REG_LS1;
52 		shift = (led - 4) << 1;
53 	}
54 
55 	ret = i2c_read(CONFIG_PCA9551_I2C_ADDR, reg, 1, &buf, 1);
56 	if (ret)
57 		return ret;
58 
59 	*state = (buf >> shift) & 0x03;
60 	return 0;
61 }
62 
63 static int pca9551_led_set_state(int led, int state)
64 {
65 	unsigned int reg;
66 	u8 shift, buf, mask;
67 	int ret;
68 
69 	if (led < 0 || led > 7) {
70 		return -EINVAL;
71 	} else if (led < 4) {
72 		reg = PCA9551_REG_LS0;
73 		shift = led << 1;
74 	} else {
75 		reg = PCA9551_REG_LS1;
76 		shift = (led - 4) << 1;
77 	}
78 	mask = 0x03 << shift;
79 
80 	ret = i2c_read(CONFIG_PCA9551_I2C_ADDR, reg, 1, &buf, 1);
81 	if (ret)
82 		return ret;
83 
84 	buf = (buf & ~mask) | ((state & 0x03) << shift);
85 
86 	ret = i2c_write(CONFIG_PCA9551_I2C_ADDR, reg, 1, &buf, 1);
87 	if (ret)
88 		return ret;
89 
90 	return 0;
91 }
92 
93 static int pca9551_led_set_blink_rate(int idx, struct pca9551_blink_rate rate)
94 {
95 	unsigned int reg;
96 	int ret;
97 
98 	switch (idx) {
99 	case 0:
100 		reg = PCA9551_REG_PSC0;
101 		break;
102 	case 1:
103 		reg = PCA9551_REG_PSC1;
104 		break;
105 	default:
106 		return -EINVAL;
107 	}
108 	reg |= PCA9551_CTRL_AI;
109 
110 	ret = i2c_write(CONFIG_PCA9551_I2C_ADDR, reg, 1, (u8 *)&rate, 2);
111 	if (ret)
112 		return ret;
113 
114 	return 0;
115 }
116 
117 /*
118  * Functions referenced by cmd_led.c or status_led.c
119  */
120 void __led_init(led_id_t id, int state)
121 {
122 }
123 
124 void __led_set(led_id_t mask, int state)
125 {
126 	if (state == CONFIG_LED_STATUS_OFF)
127 		pca9551_led_set_state(mask, PCA9551_LED_STATE_OFF);
128 	else
129 		pca9551_led_set_state(mask, PCA9551_LED_STATE_ON);
130 }
131 
132 void __led_toggle(led_id_t mask)
133 {
134 	int state = 0;
135 
136 	pca9551_led_get_state(mask, &state);
137 	pca9551_led_set_state(mask, !state);
138 }
139 
140 void __led_blink(led_id_t mask, int freq)
141 {
142 	struct pca9551_blink_rate rate;
143 	int mode;
144 	int idx;
145 
146 	if ((freq == freq_last) || (mask == mask_last)) {
147 		idx = idx_last;
148 		mode = mode_last;
149 	} else {
150 		/* Toggle blink index */
151 		if (idx_last == 0) {
152 			idx = 1;
153 			mode = PCA9551_LED_STATE_BLINK1;
154 		} else {
155 			idx = 0;
156 			mode = PCA9551_LED_STATE_BLINK0;
157 		}
158 
159 		idx_last = idx;
160 		mode_last = mode;
161 	}
162 	freq_last = freq;
163 	mask_last = mask;
164 
165 	rate.psc = ((freq * 38) / 1000) - 1;
166 	rate.pwm = 128;		/* 50% duty cycle */
167 
168 	pca9551_led_set_blink_rate(idx, rate);
169 	pca9551_led_set_state(mask, mode);
170 }
171