drivers/spmi/spmi-msm.c

   1 /*
   2  * Qualcomm SPMI bus driver
   3  *
   4  * (C) Copyright 2015 Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
   5  *
   6  * Loosely based on Little Kernel driver
   7  *
   8  * SPDX-License-Identifier:     BSD-3-Clause
   9  */
  10
  11 #include <common.h>
  12 #include <dm.h>
  13 #include <errno.h>
  14 #include <fdtdec.h>
  15 #include <asm/io.h>
  16 #include <spmi/spmi.h>
  17
  18 DECLARE_GLOBAL_DATA_PTR;
  19
  20 #define ARB_CHANNEL_OFFSET(n)           (0x4 * (n))
  21 #define SPMI_CH_OFFSET(chnl)            ((chnl) * 0x8000)
  22
  23 #define SPMI_REG_CMD0                   0x0
  24 #define SPMI_REG_CONFIG                 0x4
  25 #define SPMI_REG_STATUS                 0x8
  26 #define SPMI_REG_WDATA                  0x10
  27 #define SPMI_REG_RDATA                  0x18
  28
  29 #define SPMI_CMD_OPCODE_SHIFT           27
  30 #define SPMI_CMD_SLAVE_ID_SHIFT         20
  31 #define SPMI_CMD_ADDR_SHIFT             12
  32 #define SPMI_CMD_ADDR_OFFSET_SHIFT      4
  33 #define SPMI_CMD_BYTE_CNT_SHIFT         0
  34
  35 #define SPMI_CMD_EXT_REG_WRITE_LONG     0x00
  36 #define SPMI_CMD_EXT_REG_READ_LONG      0x01
  37
  38 #define SPMI_STATUS_DONE                0x1
  39
  40 #define SPMI_MAX_CHANNELS       128
  41 #define SPMI_MAX_SLAVES         16
  42 #define SPMI_MAX_PERIPH         256
  43
  44 struct msm_spmi_priv {
  45         phys_addr_t arb_chnl; /* ARB channel mapping base */
  46         phys_addr_t spmi_core; /* SPMI core */
  47         phys_addr_t spmi_obs; /* SPMI observer */
  48         /* SPMI channel map */
  49         uint8_t channel_map[SPMI_MAX_SLAVES][SPMI_MAX_PERIPH];
  50 };
  51
  52 static int msm_spmi_write(struct udevice *dev, int usid, int pid, int off,
  53                           uint8_t val)
  54 {
  55         struct msm_spmi_priv *priv = dev_get_priv(dev);
  56         unsigned channel;
  57         uint32_t reg = 0;
  58
  59         if (usid >= SPMI_MAX_SLAVES)
  60                 return -EINVAL;
  61         if (pid >= SPMI_MAX_PERIPH)
  62                 return -EINVAL;
  63
  64         channel = priv->channel_map[usid][pid];
  65
  66         /* Disable IRQ mode for the current channel*/
  67         writel(0x0, priv->spmi_core + SPMI_CH_OFFSET(channel) +
  68                SPMI_REG_CONFIG);
  69
  70         /* Write single byte */
  71         writel(val, priv->spmi_core + SPMI_CH_OFFSET(channel) + SPMI_REG_WDATA);
  72
  73         /* Prepare write command */
  74         reg |= SPMI_CMD_EXT_REG_WRITE_LONG << SPMI_CMD_OPCODE_SHIFT;
  75         reg |= (usid << SPMI_CMD_SLAVE_ID_SHIFT);
  76         reg |= (pid << SPMI_CMD_ADDR_SHIFT);
  77         reg |= (off << SPMI_CMD_ADDR_OFFSET_SHIFT);
  78         reg |= 1; /* byte count */
  79
  80         /* Send write command */
  81         writel(reg, priv->spmi_core + SPMI_CH_OFFSET(channel) + SPMI_REG_CMD0);
  82
  83         /* Wait till CMD DONE status */
  84         reg = 0;
  85         while (!reg) {
  86                 reg = readl(priv->spmi_core + SPMI_CH_OFFSET(channel) +
  87                             SPMI_REG_STATUS);
  88         }
  89
  90         if (reg ^ SPMI_STATUS_DONE) {
  91                 printf("SPMI write failure.\n");
  92                 return -EIO;
  93         }
  94
  95         return 0;
  96 }
  97
  98 static int msm_spmi_read(struct udevice *dev, int usid, int pid, int off)
  99 {
 100         struct msm_spmi_priv *priv = dev_get_priv(dev);
 101         unsigned channel;
 102         uint32_t reg = 0;
 103
 104         if (usid >= SPMI_MAX_SLAVES)
 105                 return -EINVAL;
 106         if (pid >= SPMI_MAX_PERIPH)
 107                 return -EINVAL;
 108
 109         channel = priv->channel_map[usid][pid];
 110
 111         /* Disable IRQ mode for the current channel*/
 112         writel(0x0, priv->spmi_obs + SPMI_CH_OFFSET(channel) + SPMI_REG_CONFIG);
 113
 114         /* Prepare read command */
 115         reg |= SPMI_CMD_EXT_REG_READ_LONG << SPMI_CMD_OPCODE_SHIFT;
 116         reg |= (usid << SPMI_CMD_SLAVE_ID_SHIFT);
 117         reg |= (pid << SPMI_CMD_ADDR_SHIFT);
 118         reg |= (off << SPMI_CMD_ADDR_OFFSET_SHIFT);
 119         reg |= 1; /* byte count */
 120
 121         /* Request read */
 122         writel(reg, priv->spmi_obs + SPMI_CH_OFFSET(channel) + SPMI_REG_CMD0);
 123
 124         /* Wait till CMD DONE status */
 125         reg = 0;
 126         while (!reg) {
 127                 reg = readl(priv->spmi_obs + SPMI_CH_OFFSET(channel) +
 128                             SPMI_REG_STATUS);
 129         }
 130
 131         if (reg ^ SPMI_STATUS_DONE) {
 132                 printf("SPMI read failure.\n");
 133                 return -EIO;
 134         }
 135
 136         /* Read the data */
 137         return readl(priv->spmi_obs + SPMI_CH_OFFSET(channel) +
 138                      SPMI_REG_RDATA) & 0xFF;
 139 }
 140
 141 static struct dm_spmi_ops msm_spmi_ops = {
 142         .read = msm_spmi_read,
 143         .write = msm_spmi_write,
 144 };
 145
 146 static int msm_spmi_probe(struct udevice *dev)
 147 {
 148         struct udevice *parent = dev->parent;
 149         struct msm_spmi_priv *priv = dev_get_priv(dev);
 150         int i;
 151
 152         priv->arb_chnl = dev_get_addr(dev);
 153         priv->spmi_core = fdtdec_get_addr_size_auto_parent(gd->fdt_blob,
 154                                                            parent->of_offset,
 155                                                            dev->of_offset,
 156                                                            "reg", 1, NULL,
 157                                                            false);
 158         priv->spmi_obs = fdtdec_get_addr_size_auto_parent(gd->fdt_blob,
 159                                                           parent->of_offset,
 160                                                           dev->of_offset, "reg",
 161                                                           2, NULL, false);
 162         if (priv->arb_chnl == FDT_ADDR_T_NONE ||
 163             priv->spmi_core == FDT_ADDR_T_NONE ||
 164             priv->spmi_obs == FDT_ADDR_T_NONE)
 165                 return -EINVAL;
 166
 167         /* Scan peripherals connected to each SPMI channel */
 168         for (i = 0; i < SPMI_MAX_CHANNELS ; i++) {
 169                 uint32_t periph = readl(priv->arb_chnl + ARB_CHANNEL_OFFSET(i));
 170                 uint8_t slave_id = (periph & 0xf0000) >> 16;
 171                 uint8_t pid = (periph & 0xff00) >> 8;
 172
 173                 priv->channel_map[slave_id][pid] = i;
 174         }
 175         return 0;
 176 }
 177
 178 static const struct udevice_id msm_spmi_ids[] = {
 179         { .compatible = "qcom,spmi-pmic-arb" },
 180         { }
 181 };
 182
 183 U_BOOT_DRIVER(msm_spmi) = {
 184         .name = "msm_spmi",
 185         .id = UCLASS_SPMI,
 186         .of_match = msm_spmi_ids,
 187         .ops = &msm_spmi_ops,
 188         .probe = msm_spmi_probe,
 189         .priv_auto_alloc_size = sizeof(struct msm_spmi_priv),
 190 };