drivers/misc/pca9551_led.c

   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 }