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 #include <linux/delay.h>
  14
  15 #define LEDS_MAX                32
  16 #define LEDS_WAIT               100
  17
  18 /* LED Mode register */
  19 #define LED_MODE_REG            0x0
  20 #define LED_MODE_OFF            0
  21 #define LED_MODE_ON             1
  22 #define LED_MODE_MASK           1
  23
  24 /* LED Control register */
  25 #define LED_CTRL_REG            0x4
  26 #define LED_CTRL_CLK_MASK       0x3
  27 #define LED_CTRL_CLK_1          0
  28 #define LED_CTRL_CLK_2          1
  29 #define LED_CTRL_CLK_4          2
  30 #define LED_CTRL_CLK_8          3
  31 #define LED_CTRL_POL_SHIFT      2
  32 #define LED_CTRL_POL_MASK       (1 << LED_CTRL_POL_SHIFT)
  33 #define LED_CTRL_BUSY_SHIFT     3
  34 #define LED_CTRL_BUSY_MASK      (1 << LED_CTRL_BUSY_SHIFT)
  35
  36 struct bcm6358_led_priv {
  37         void __iomem *regs;
  38         uint8_t pin;
  39         bool active_low;
  40 };
  41
  42 static void bcm6358_led_busy(void __iomem *regs)
  43 {
  44         while (readl_be(regs + LED_CTRL_REG) & LED_CTRL_BUSY_MASK)
  45                 udelay(LEDS_WAIT);
  46 }
  47
  48 static unsigned long bcm6358_led_get_mode(struct bcm6358_led_priv *priv)
  49 {
  50         bcm6358_led_busy(priv->regs);
  51
  52         return (readl_be(priv->regs + LED_MODE_REG) >> priv->pin) &
  53                LED_MODE_MASK;
  54 }
  55
  56 static int bcm6358_led_set_mode(struct bcm6358_led_priv *priv, uint8_t mode)
  57 {
  58         bcm6358_led_busy(priv->regs);
  59
  60         clrsetbits_be32(priv->regs + LED_MODE_REG,
  61                         (LED_MODE_MASK << priv->pin),
  62                         (mode << priv->pin));
  63
  64         return 0;
  65 }
  66
  67 static enum led_state_t bcm6358_led_get_state(struct udevice *dev)
  68 {
  69         struct bcm6358_led_priv *priv = dev_get_priv(dev);
  70         enum led_state_t state = LEDST_OFF;
  71
  72         switch (bcm6358_led_get_mode(priv)) {
  73         case LED_MODE_OFF:
  74                 state = (priv->active_low ? LEDST_ON : LEDST_OFF);
  75                 break;
  76         case LED_MODE_ON:
  77                 state = (priv->active_low ? LEDST_OFF : LEDST_ON);
  78                 break;
  79         }
  80
  81         return state;
  82 }
  83
  84 static int bcm6358_led_set_state(struct udevice *dev, enum led_state_t state)
  85 {
  86         struct bcm6358_led_priv *priv = dev_get_priv(dev);
  87         unsigned long mode;
  88
  89         switch (state) {
  90         case LEDST_OFF:
  91                 mode = (priv->active_low ? LED_MODE_ON : LED_MODE_OFF);
  92                 break;
  93         case LEDST_ON:
  94                 mode = (priv->active_low ? LED_MODE_OFF : LED_MODE_ON);
  95                 break;
  96         case LEDST_TOGGLE:
  97                 if (bcm6358_led_get_state(dev) == LEDST_OFF)
  98                         return bcm6358_led_set_state(dev, LEDST_ON);
  99                 else
 100                         return bcm6358_led_set_state(dev, LEDST_OFF);
 101                 break;
 102         default:
 103                 return -ENOSYS;
 104         }
 105
 106         return bcm6358_led_set_mode(priv, mode);
 107 }
 108
 109 static const struct led_ops bcm6358_led_ops = {
 110         .get_state = bcm6358_led_get_state,
 111         .set_state = bcm6358_led_set_state,
 112 };
 113
 114 static int bcm6358_led_probe(struct udevice *dev)
 115 {
 116         struct led_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
 117
 118         /* Top-level LED node */
 119         if (!uc_plat->label) {
 120                 void __iomem *regs;
 121                 unsigned int clk_div;
 122                 u32 set_bits = 0;
 123
 124                 regs = dev_remap_addr(dev);
 125                 if (!regs)
 126                         return -EINVAL;
 127
 128                 if (dev_read_bool(dev, "brcm,clk-dat-low"))
 129                         set_bits |= LED_CTRL_POL_MASK;
 130                 clk_div = dev_read_u32_default(dev, "brcm,clk-div",
 131                                                LED_CTRL_CLK_1);
 132                 switch (clk_div) {
 133                 case 8:
 134                         set_bits |= LED_CTRL_CLK_8;
 135                         break;
 136                 case 4:
 137                         set_bits |= LED_CTRL_CLK_4;
 138                         break;
 139                 case 2:
 140                         set_bits |= LED_CTRL_CLK_2;
 141                         break;
 142                 default:
 143                         set_bits |= LED_CTRL_CLK_1;
 144                         break;
 145                 }
 146
 147                 bcm6358_led_busy(regs);
 148                 clrsetbits_be32(regs + LED_CTRL_REG,
 149                                 LED_CTRL_POL_MASK | LED_CTRL_CLK_MASK,
 150                                 set_bits);
 151         } else {
 152                 struct bcm6358_led_priv *priv = dev_get_priv(dev);
 153                 unsigned int pin;
 154
 155                 priv->regs = dev_remap_addr(dev);
 156                 if (!priv->regs)
 157                         return -EINVAL;
 158
 159                 pin = dev_read_u32_default(dev, "reg", LEDS_MAX);
 160                 if (pin >= LEDS_MAX)
 161                         return -EINVAL;
 162
 163                 priv->pin = pin;
 164
 165                 if (dev_read_bool(dev, "active-low"))
 166                         priv->active_low = true;
 167         }
 168
 169         return 0;
 170 }
 171
 172 static int bcm6358_led_bind(struct udevice *parent)
 173 {
 174         ofnode node;
 175
 176         dev_for_each_subnode(node, parent) {
 177                 struct led_uc_plat *uc_plat;
 178                 struct udevice *dev;
 179                 const char *label;
 180                 int ret;
 181
 182                 label = ofnode_read_string(node, "label");
 183                 if (!label) {
 184                         debug("%s: node %s has no label\n", __func__,
 185                               ofnode_get_name(node));
 186                         return -EINVAL;
 187                 }
 188
 189                 ret = device_bind_driver_to_node(parent, "bcm6358-led",
 190                                                  ofnode_get_name(node),
 191                                                  node, &dev);
 192                 if (ret)
 193                         return ret;
 194
 195                 uc_plat = dev_get_uclass_platdata(dev);
 196                 uc_plat->label = label;
 197         }
 198
 199         return 0;
 200 }
 201
 202 static const struct udevice_id bcm6358_led_ids[] = {
 203         { .compatible = "brcm,bcm6358-leds" },
 204         { /* sentinel */ }
 205 };
 206
 207 U_BOOT_DRIVER(bcm6358_led) = {
 208         .name = "bcm6358-led",
 209         .id = UCLASS_LED,
 210         .of_match = bcm6358_led_ids,
 211         .bind = bcm6358_led_bind,
 212         .probe = bcm6358_led_probe,
 213         .priv_auto_alloc_size = sizeof(struct bcm6358_led_priv),
 214         .ops = &bcm6358_led_ops,
 215 };