drivers/led/led_bcm6358.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
   4  */
   5
   6 #include <common.h>
   7 #include <dm.h>
   8 #include <errno.h>
   9 #include <led.h>
  10 #include <log.h>
  11 #include <asm/io.h>
  12 #include <dm/lists.h>
  13
  14 #define LEDS_MAX                32
  15 #define LEDS_WAIT               100
  16
  17 /* LED Mode register */
  18 #define LED_MODE_REG            0x0
  19 #define LED_MODE_OFF            0
  20 #define LED_MODE_ON             1
  21 #define LED_MODE_MASK           1
  22
  23 /* LED Control register */
  24 #define LED_CTRL_REG            0x4
  25 #define LED_CTRL_CLK_MASK       0x3
  26 #define LED_CTRL_CLK_1          0
  27 #define LED_CTRL_CLK_2          1
  28 #define LED_CTRL_CLK_4          2
  29 #define LED_CTRL_CLK_8          3
  30 #define LED_CTRL_POL_SHIFT      2
  31 #define LED_CTRL_POL_MASK       (1 << LED_CTRL_POL_SHIFT)
  32 #define LED_CTRL_BUSY_SHIFT     3
  33 #define LED_CTRL_BUSY_MASK      (1 << LED_CTRL_BUSY_SHIFT)
  34
  35 struct bcm6358_led_priv {
  36         void __iomem *regs;
  37         uint8_t pin;
  38         bool active_low;
  39 };
  40
  41 static void bcm6358_led_busy(void __iomem *regs)
  42 {
  43         while (readl_be(regs + LED_CTRL_REG) & LED_CTRL_BUSY_MASK)
  44                 udelay(LEDS_WAIT);
  45 }
  46
  47 static unsigned long bcm6358_led_get_mode(struct bcm6358_led_priv *priv)
  48 {
  49         bcm6358_led_busy(priv->regs);
  50
  51         return (readl_be(priv->regs + LED_MODE_REG) >> priv->pin) &
  52                LED_MODE_MASK;
  53 }
  54
  55 static int bcm6358_led_set_mode(struct bcm6358_led_priv *priv, uint8_t mode)
  56 {
  57         bcm6358_led_busy(priv->regs);
  58
  59         clrsetbits_be32(priv->regs + LED_MODE_REG,
  60                         (LED_MODE_MASK << priv->pin),
  61                         (mode << priv->pin));
  62
  63         return 0;
  64 }
  65
  66 static enum led_state_t bcm6358_led_get_state(struct udevice *dev)
  67 {
  68         struct bcm6358_led_priv *priv = dev_get_priv(dev);
  69         enum led_state_t state = LEDST_OFF;
  70
  71         switch (bcm6358_led_get_mode(priv)) {
  72         case LED_MODE_OFF:
  73                 state = (priv->active_low ? LEDST_ON : LEDST_OFF);
  74                 break;
  75         case LED_MODE_ON:
  76                 state = (priv->active_low ? LEDST_OFF : LEDST_ON);
  77                 break;
  78         }
  79
  80         return state;
  81 }
  82
  83 static int bcm6358_led_set_state(struct udevice *dev, enum led_state_t state)
  84 {
  85         struct bcm6358_led_priv *priv = dev_get_priv(dev);
  86         unsigned long mode;
  87
  88         switch (state) {
  89         case LEDST_OFF:
  90                 mode = (priv->active_low ? LED_MODE_ON : LED_MODE_OFF);
  91                 break;
  92         case LEDST_ON:
  93                 mode = (priv->active_low ? LED_MODE_OFF : LED_MODE_ON);
  94                 break;
  95         case LEDST_TOGGLE:
  96                 if (bcm6358_led_get_state(dev) == LEDST_OFF)
  97                         return bcm6358_led_set_state(dev, LEDST_ON);
  98                 else
  99                         return bcm6358_led_set_state(dev, LEDST_OFF);
 100                 break;
 101         default:
 102                 return -ENOSYS;
 103         }
 104
 105         return bcm6358_led_set_mode(priv, mode);
 106 }
 107
 108 static const struct led_ops bcm6358_led_ops = {
 109         .get_state = bcm6358_led_get_state,
 110         .set_state = bcm6358_led_set_state,
 111 };
 112
 113 static int bcm6358_led_probe(struct udevice *dev)
 114 {
 115         struct led_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
 116
 117         /* Top-level LED node */
 118         if (!uc_plat->label) {
 119                 void __iomem *regs;
 120                 unsigned int clk_div;
 121                 u32 set_bits = 0;
 122
 123                 regs = dev_remap_addr(dev);
 124                 if (!regs)
 125                         return -EINVAL;
 126
 127                 if (dev_read_bool(dev, "brcm,clk-dat-low"))
 128                         set_bits |= LED_CTRL_POL_MASK;
 129                 clk_div = dev_read_u32_default(dev, "brcm,clk-div",
 130                                                LED_CTRL_CLK_1);
 131                 switch (clk_div) {
 132                 case 8:
 133                         set_bits |= LED_CTRL_CLK_8;
 134                         break;
 135                 case 4:
 136                         set_bits |= LED_CTRL_CLK_4;
 137                         break;
 138                 case 2:
 139                         set_bits |= LED_CTRL_CLK_2;
 140                         break;
 141                 default:
 142                         set_bits |= LED_CTRL_CLK_1;
 143                         break;
 144                 }
 145
 146                 bcm6358_led_busy(regs);
 147                 clrsetbits_be32(regs + LED_CTRL_REG,
 148                                 LED_CTRL_POL_MASK | LED_CTRL_CLK_MASK,
 149                                 set_bits);
 150         } else {
 151                 struct bcm6358_led_priv *priv = dev_get_priv(dev);
 152                 unsigned int pin;
 153
 154                 priv->regs = dev_remap_addr(dev);
 155                 if (!priv->regs)
 156                         return -EINVAL;
 157
 158                 pin = dev_read_u32_default(dev, "reg", LEDS_MAX);
 159                 if (pin >= LEDS_MAX)
 160                         return -EINVAL;
 161
 162                 priv->pin = pin;
 163
 164                 if (dev_read_bool(dev, "active-low"))
 165                         priv->active_low = true;
 166         }
 167
 168         return 0;
 169 }
 170
 171 static int bcm6358_led_bind(struct udevice *parent)
 172 {
 173         ofnode node;
 174
 175         dev_for_each_subnode(node, parent) {
 176                 struct led_uc_plat *uc_plat;
 177                 struct udevice *dev;
 178                 const char *label;
 179                 int ret;
 180
 181                 label = ofnode_read_string(node, "label");
 182                 if (!label) {
 183                         debug("%s: node %s has no label\n", __func__,
 184                               ofnode_get_name(node));
 185                         return -EINVAL;
 186                 }
 187
 188                 ret = device_bind_driver_to_node(parent, "bcm6358-led",
 189                                                  ofnode_get_name(node),
 190                                                  node, &dev);
 191                 if (ret)
 192                         return ret;
 193
 194                 uc_plat = dev_get_uclass_platdata(dev);
 195                 uc_plat->label = label;
 196         }
 197
 198         return 0;
 199 }
 200
 201 static const struct udevice_id bcm6358_led_ids[] = {
 202         { .compatible = "brcm,bcm6358-leds" },
 203         { /* sentinel */ }
 204 };
 205
 206 U_BOOT_DRIVER(bcm6358_led) = {
 207         .name = "bcm6358-led",
 208         .id = UCLASS_LED,
 209         .of_match = bcm6358_led_ids,
 210         .bind = bcm6358_led_bind,
 211         .probe = bcm6358_led_probe,
 212         .priv_auto_alloc_size = sizeof(struct bcm6358_led_priv),
 213         .ops = &bcm6358_led_ops,
 214 };