drivers/led/led_bcm6358.c

   1 /*
   2  * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #include <common.h>
   8 #include <dm.h>
   9 #include <errno.h>
  10 #include <led.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 DECLARE_GLOBAL_DATA_PTR;
  36
  37 struct bcm6358_led_priv {
  38         void __iomem *regs;
  39         uint8_t pin;
  40         bool active_low;
  41 };
  42
  43 static void bcm6358_led_busy(void __iomem *regs)
  44 {
  45         while (readl_be(regs + LED_CTRL_REG) & LED_CTRL_BUSY_MASK)
  46                 udelay(LEDS_WAIT);
  47 }
  48
  49 static unsigned long bcm6358_led_get_mode(struct bcm6358_led_priv *priv)
  50 {
  51         bcm6358_led_busy(priv->regs);
  52
  53         return (readl_be(priv->regs + LED_MODE_REG) >> priv->pin) &
  54                LED_MODE_MASK;
  55 }
  56
  57 static int bcm6358_led_set_mode(struct bcm6358_led_priv *priv, uint8_t mode)
  58 {
  59         bcm6358_led_busy(priv->regs);
  60
  61         clrsetbits_be32(priv->regs + LED_MODE_REG,
  62                         (LED_MODE_MASK << priv->pin),
  63                         (mode << priv->pin));
  64
  65         return 0;
  66 }
  67
  68 static enum led_state_t bcm6358_led_get_state(struct udevice *dev)
  69 {
  70         struct bcm6358_led_priv *priv = dev_get_priv(dev);
  71         enum led_state_t state = LEDST_OFF;
  72
  73         switch (bcm6358_led_get_mode(priv)) {
  74         case LED_MODE_OFF:
  75                 state = (priv->active_low ? LEDST_ON : LEDST_OFF);
  76                 break;
  77         case LED_MODE_ON:
  78                 state = (priv->active_low ? LEDST_OFF : LEDST_ON);
  79                 break;
  80         }
  81
  82         return state;
  83 }
  84
  85 static int bcm6358_led_set_state(struct udevice *dev, enum led_state_t state)
  86 {
  87         struct bcm6358_led_priv *priv = dev_get_priv(dev);
  88         unsigned long mode;
  89
  90         switch (state) {
  91         case LEDST_OFF:
  92                 mode = (priv->active_low ? LED_MODE_ON : LED_MODE_OFF);
  93                 break;
  94         case LEDST_ON:
  95                 mode = (priv->active_low ? LED_MODE_OFF : LED_MODE_ON);
  96                 break;
  97         case LEDST_TOGGLE:
  98                 if (bcm6358_led_get_state(dev) == LEDST_OFF)
  99                         return bcm6358_led_set_state(dev, LEDST_ON);
 100                 else
 101                         return bcm6358_led_set_state(dev, LEDST_OFF);
 102                 break;
 103         default:
 104                 return -ENOSYS;
 105         }
 106
 107         return bcm6358_led_set_mode(priv, mode);
 108 }
 109
 110 static const struct led_ops bcm6358_led_ops = {
 111         .get_state = bcm6358_led_get_state,
 112         .set_state = bcm6358_led_set_state,
 113 };
 114
 115 static int bcm6358_led_probe(struct udevice *dev)
 116 {
 117         struct led_uc_plat *uc_plat = dev_get_uclass_platdata(dev);
 118         fdt_addr_t addr;
 119         fdt_size_t size;
 120
 121         /* Top-level LED node */
 122         if (!uc_plat->label) {
 123                 void __iomem *regs;
 124                 unsigned int clk_div;
 125                 u32 set_bits = 0;
 126
 127                 addr = devfdt_get_addr_size_index(dev, 0, &size);
 128                 if (addr == FDT_ADDR_T_NONE)
 129                         return -EINVAL;
 130
 131                 regs = ioremap(addr, size);
 132
 133                 if (fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
 134                                     "brcm,clk-dat-low"))
 135                         set_bits |= LED_CTRL_POL_MASK;
 136                 clk_div = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
 137                                           "brcm,clk-div", LED_CTRL_CLK_1);
 138                 switch (clk_div) {
 139                 case 8:
 140                         set_bits |= LED_CTRL_CLK_8;
 141                         break;
 142                 case 4:
 143                         set_bits |= LED_CTRL_CLK_4;
 144                         break;
 145                 case 2:
 146                         set_bits |= LED_CTRL_CLK_2;
 147                         break;
 148                 default:
 149                         set_bits |= LED_CTRL_CLK_1;
 150                         break;
 151                 }
 152
 153                 bcm6358_led_busy(regs);
 154                 clrsetbits_be32(regs + LED_CTRL_REG,
 155                                 LED_CTRL_POL_MASK | LED_CTRL_CLK_MASK,
 156                                 set_bits);
 157         } else {
 158                 struct bcm6358_led_priv *priv = dev_get_priv(dev);
 159                 unsigned int pin;
 160
 161                 addr = devfdt_get_addr_size_index(dev_get_parent(dev), 0,
 162                                                   &size);
 163                 if (addr == FDT_ADDR_T_NONE)
 164                         return -EINVAL;
 165
 166                 pin = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev), "reg",
 167                                       LEDS_MAX);
 168                 if (pin >= LEDS_MAX)
 169                         return -EINVAL;
 170
 171                 priv->regs = ioremap(addr, size);
 172                 priv->pin = pin;
 173
 174                 if (fdtdec_get_bool(gd->fdt_blob, dev_of_offset(dev),
 175                                     "active-low"))
 176                         priv->active_low = true;
 177         }
 178
 179         return 0;
 180 }
 181
 182 static int bcm6358_led_bind(struct udevice *parent)
 183 {
 184         const void *blob = gd->fdt_blob;
 185         int node;
 186
 187         for (node = fdt_first_subnode(blob, dev_of_offset(parent));
 188              node > 0;
 189              node = fdt_next_subnode(blob, node)) {
 190                 struct led_uc_plat *uc_plat;
 191                 struct udevice *dev;
 192                 const char *label;
 193                 int ret;
 194
 195                 label = fdt_getprop(blob, node, "label", NULL);
 196                 if (!label) {
 197                         debug("%s: node %s has no label\n", __func__,
 198                               fdt_get_name(blob, node, NULL));
 199                         return -EINVAL;
 200                 }
 201
 202                 ret = device_bind_driver_to_node(parent, "bcm6358-led",
 203                                                  fdt_get_name(blob, node, NULL),
 204                                                  node, &dev);
 205                 if (ret)
 206                         return ret;
 207
 208                 uc_plat = dev_get_uclass_platdata(dev);
 209                 uc_plat->label = label;
 210         }
 211
 212         return 0;
 213 }
 214
 215 static const struct udevice_id bcm6358_led_ids[] = {
 216         { .compatible = "brcm,bcm6358-leds" },
 217         { /* sentinel */ }
 218 };
 219
 220 U_BOOT_DRIVER(bcm6358_led) = {
 221         .name = "bcm6358-led",
 222         .id = UCLASS_LED,
 223         .of_match = bcm6358_led_ids,
 224         .bind = bcm6358_led_bind,
 225         .probe = bcm6358_led_probe,
 226         .priv_auto_alloc_size = sizeof(struct bcm6358_led_priv),
 227         .ops = &bcm6358_led_ops,
 228 };