drivers/i2c/tegra186_bpmp_i2c.c

   1 /*
   2  * Copyright (c) 2016, NVIDIA CORPORATION.
   3  *
   4  * SPDX-License-Identifier: GPL-2.0
   5  */
   6
   7 #include <common.h>
   8 #include <dm.h>
   9 #include <i2c.h>
  10 #include <misc.h>
  11 #include <asm/arch-tegra/bpmp_abi.h>
  12
  13 DECLARE_GLOBAL_DATA_PTR;
  14
  15 struct tegra186_bpmp_i2c {
  16         uint32_t bpmp_bus_id;
  17 };
  18
  19 static inline void serialize_u16(uint8_t **p, uint16_t val)
  20 {
  21         (*p)[0] = val & 0xff;
  22         (*p)[1] = val >> 8;
  23         (*p) += 2;
  24 }
  25
  26 /* These just happen to have the same values as I2C_M_* and SERIALI2C_* */
  27 #define SUPPORTED_FLAGS \
  28         (I2C_M_TEN | \
  29         I2C_M_RD | \
  30         I2C_M_STOP | \
  31         I2C_M_NOSTART | \
  32         I2C_M_REV_DIR_ADDR | \
  33         I2C_M_IGNORE_NAK | \
  34         I2C_M_NO_RD_ACK | \
  35         I2C_M_RECV_LEN)
  36
  37 static int tegra186_bpmp_i2c_xfer(struct udevice *dev, struct i2c_msg *msg,
  38                                   int nmsgs)
  39 {
  40         struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
  41         struct mrq_i2c_request req;
  42         struct mrq_i2c_response resp;
  43         uint8_t *p;
  44         int left, i, ret;
  45
  46         req.cmd = CMD_I2C_XFER;
  47         req.xfer.bus_id = priv->bpmp_bus_id;
  48         p = &req.xfer.data_buf[0];
  49         left = ARRAY_SIZE(req.xfer.data_buf);
  50         for (i = 0; i < nmsgs; i++) {
  51                 int len = 6;
  52                 if (!(msg[i].flags & I2C_M_RD))
  53                         len += msg[i].len;
  54                 if ((len >= BIT(16)) || (len > left))
  55                         return -ENOSPC;
  56
  57                 if (msg[i].flags & ~SUPPORTED_FLAGS)
  58                         return -EINVAL;
  59
  60                 serialize_u16(&p, msg[i].addr);
  61                 serialize_u16(&p, msg[i].flags);
  62                 serialize_u16(&p, msg[i].len);
  63                 if (!(msg[i].flags & I2C_M_RD)) {
  64                         memcpy(p, msg[i].buf, msg[i].len);
  65                         p += msg[i].len;
  66                 }
  67         }
  68         req.xfer.data_size = p - &req.xfer.data_buf[0];
  69
  70         ret = misc_call(dev->parent, MRQ_I2C, &req, sizeof(req), &resp,
  71                         sizeof(resp));
  72         if (ret < 0)
  73                 return ret;
  74
  75         p = &resp.xfer.data_buf[0];
  76         left = resp.xfer.data_size;
  77         if (left > ARRAY_SIZE(resp.xfer.data_buf))
  78                 return -EINVAL;
  79         for (i = 0; i < nmsgs; i++) {
  80                 if (msg[i].flags & I2C_M_RD) {
  81                         memcpy(msg[i].buf, p, msg[i].len);
  82                         p += msg[i].len;
  83                 }
  84         }
  85
  86         return 0;
  87 }
  88
  89 static int tegra186_bpmp_i2c_probe(struct udevice *dev)
  90 {
  91         struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
  92
  93         priv->bpmp_bus_id = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
  94                                             "nvidia,bpmp-bus-id", U32_MAX);
  95         if (priv->bpmp_bus_id == U32_MAX) {
  96                 debug("%s: could not parse nvidia,bpmp-bus-id\n", __func__);
  97                 return -EINVAL;
  98         }
  99
 100         return 0;
 101 }
 102
 103 static const struct dm_i2c_ops tegra186_bpmp_i2c_ops = {
 104         .xfer = tegra186_bpmp_i2c_xfer,
 105 };
 106
 107 static const struct udevice_id tegra186_bpmp_i2c_ids[] = {
 108         { .compatible = "nvidia,tegra186-bpmp-i2c" },
 109         { }
 110 };
 111
 112 U_BOOT_DRIVER(i2c_gpio) = {
 113         .name   = "tegra186_bpmp_i2c",
 114         .id     = UCLASS_I2C,
 115         .of_match = tegra186_bpmp_i2c_ids,
 116         .probe  = tegra186_bpmp_i2c_probe,
 117         .priv_auto_alloc_size = sizeof(struct tegra186_bpmp_i2c),
 118         .ops    = &tegra186_bpmp_i2c_ops,
 119 };