drivers/misc/pca9551_led.c

   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
  30 struct 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
  35 static int freq_last = -1;
  36 static int mask_last = -1;
  37 static int idx_last = -1;
  38 static int mode_last;
  39
  40 static int pca9551_led_get_state(int led, int *state)
  41 {
  42         unsigned int reg;
  43         u8 shift, buf;
  44         int ret;
  45
  46         if (led < 0 || led > 7) {
  47                 return -EINVAL;
  48         } else if (led < 4) {
  49                 reg = PCA9551_REG_LS0;
  50                 shift = led << 1;
  51         } else {
  52                 reg = PCA9551_REG_LS1;
  53                 shift = (led - 4) << 1;
  54         }
  55
  56         ret = i2c_read(CONFIG_PCA9551_I2C_ADDR, reg, 1, &buf, 1);
  57         if (ret)
  58                 return ret;
  59
  60         *state = (buf >> shift) & 0x03;
  61         return 0;
  62 }
  63
  64 static int pca9551_led_set_state(int led, int state)
  65 {
  66         unsigned int reg;
  67         u8 shift, buf, mask;
  68         int ret;
  69
  70         if (led < 0 || led > 7) {
  71                 return -EINVAL;
  72         } else if (led < 4) {
  73                 reg = PCA9551_REG_LS0;
  74                 shift = led << 1;
  75         } else {
  76                 reg = PCA9551_REG_LS1;
  77                 shift = (led - 4) << 1;
  78         }
  79         mask = 0x03 << shift;
  80
  81         ret = i2c_read(CONFIG_PCA9551_I2C_ADDR, reg, 1, &buf, 1);
  82         if (ret)
  83                 return ret;
  84
  85         buf = (buf & ~mask) | ((state & 0x03) << shift);
  86
  87         ret = i2c_write(CONFIG_PCA9551_I2C_ADDR, reg, 1, &buf, 1);
  88         if (ret)
  89                 return ret;
  90
  91         return 0;
  92 }
  93
  94 static int pca9551_led_set_blink_rate(int idx, struct pca9551_blink_rate rate)
  95 {
  96         unsigned int reg;
  97         int ret;
  98
  99         switch (idx) {
 100         case 0:
 101                 reg = PCA9551_REG_PSC0;
 102                 break;
 103         case 1:
 104                 reg = PCA9551_REG_PSC1;
 105                 break;
 106         default:
 107                 return -EINVAL;
 108         }
 109         reg |= PCA9551_CTRL_AI;
 110
 111         ret = i2c_write(CONFIG_PCA9551_I2C_ADDR, reg, 1, (u8 *)&rate, 2);
 112         if (ret)
 113                 return ret;
 114
 115         return 0;
 116 }
 117
 118 /*
 119  * Functions referenced by cmd_led.c or status_led.c
 120  */
 121 void __led_init(led_id_t id, int state)
 122 {
 123 }
 124
 125 void __led_set(led_id_t mask, int state)
 126 {
 127         if (state == CONFIG_LED_STATUS_OFF)
 128                 pca9551_led_set_state(mask, PCA9551_LED_STATE_OFF);
 129         else
 130                 pca9551_led_set_state(mask, PCA9551_LED_STATE_ON);
 131 }
 132
 133 void __led_toggle(led_id_t mask)
 134 {
 135         int state = 0;
 136
 137         pca9551_led_get_state(mask, &state);
 138         pca9551_led_set_state(mask, !state);
 139 }
 140
 141 void __led_blink(led_id_t mask, int freq)
 142 {
 143         struct pca9551_blink_rate rate;
 144         int mode;
 145         int idx;
 146
 147         if ((freq == freq_last) || (mask == mask_last)) {
 148                 idx = idx_last;
 149                 mode = mode_last;
 150         } else {
 151                 /* Toggle blink index */
 152                 if (idx_last == 0) {
 153                         idx = 1;
 154                         mode = PCA9551_LED_STATE_BLINK1;
 155                 } else {
 156                         idx = 0;
 157                         mode = PCA9551_LED_STATE_BLINK0;
 158                 }
 159
 160                 idx_last = idx;
 161                 mode_last = mode;
 162         }
 163         freq_last = freq;
 164         mask_last = mask;
 165
 166         rate.psc = ((freq * 38) / 1000) - 1;
 167         rate.pwm = 128;         /* 50% duty cycle */
 168
 169         pca9551_led_set_blink_rate(idx, rate);
 170         pca9551_led_set_state(mask, mode);
 171 }