drivers/i2c/tegra186_bpmp_i2c.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2016, NVIDIA CORPORATION.
   4  */
   5
   6 #include <common.h>
   7 #include <dm.h>
   8 #include <i2c.h>
   9 #include <misc.h>
  10 #include <asm/arch-tegra/bpmp_abi.h>
  11
  12 DECLARE_GLOBAL_DATA_PTR;
  13
  14 struct tegra186_bpmp_i2c {
  15         uint32_t bpmp_bus_id;
  16 };
  17
  18 static inline void serialize_u16(uint8_t **p, uint16_t val)
  19 {
  20         (*p)[0] = val & 0xff;
  21         (*p)[1] = val >> 8;
  22         (*p) += 2;
  23 }
  24
  25 /* These just happen to have the same values as I2C_M_* and SERIALI2C_* */
  26 #define SUPPORTED_FLAGS \
  27         (I2C_M_TEN | \
  28         I2C_M_RD | \
  29         I2C_M_STOP | \
  30         I2C_M_NOSTART | \
  31         I2C_M_REV_DIR_ADDR | \
  32         I2C_M_IGNORE_NAK | \
  33         I2C_M_NO_RD_ACK | \
  34         I2C_M_RECV_LEN)
  35
  36 static int tegra186_bpmp_i2c_xfer(struct udevice *dev, struct i2c_msg *msg,
  37                                   int nmsgs)
  38 {
  39         struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
  40         struct mrq_i2c_request req;
  41         struct mrq_i2c_response resp;
  42         uint8_t *p;
  43         int left, i, ret;
  44
  45         req.cmd = CMD_I2C_XFER;
  46         req.xfer.bus_id = priv->bpmp_bus_id;
  47         p = &req.xfer.data_buf[0];
  48         left = ARRAY_SIZE(req.xfer.data_buf);
  49         for (i = 0; i < nmsgs; i++) {
  50                 int len = 6;
  51                 if (!(msg[i].flags & I2C_M_RD))
  52                         len += msg[i].len;
  53                 if ((len >= BIT(16)) || (len > left))
  54                         return -ENOSPC;
  55
  56                 if (msg[i].flags & ~SUPPORTED_FLAGS)
  57                         return -EINVAL;
  58
  59                 serialize_u16(&p, msg[i].addr);
  60                 serialize_u16(&p, msg[i].flags);
  61                 serialize_u16(&p, msg[i].len);
  62                 if (!(msg[i].flags & I2C_M_RD)) {
  63                         memcpy(p, msg[i].buf, msg[i].len);
  64                         p += msg[i].len;
  65                 }
  66         }
  67         req.xfer.data_size = p - &req.xfer.data_buf[0];
  68
  69         ret = misc_call(dev->parent, MRQ_I2C, &req, sizeof(req), &resp,
  70                         sizeof(resp));
  71         if (ret < 0)
  72                 return ret;
  73
  74         p = &resp.xfer.data_buf[0];
  75         left = resp.xfer.data_size;
  76         if (left > ARRAY_SIZE(resp.xfer.data_buf))
  77                 return -EINVAL;
  78         for (i = 0; i < nmsgs; i++) {
  79                 if (msg[i].flags & I2C_M_RD) {
  80                         memcpy(msg[i].buf, p, msg[i].len);
  81                         p += msg[i].len;
  82                 }
  83         }
  84
  85         return 0;
  86 }
  87
  88 static int tegra186_bpmp_probe_chip(struct udevice *bus, uint chip_addr,
  89                                     uint chip_flags)
  90 {
  91         return 0;
  92 }
  93
  94 static int tegra186_bpmp_i2c_probe(struct udevice *dev)
  95 {
  96         struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
  97
  98         priv->bpmp_bus_id = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
  99                                             "nvidia,bpmp-bus-id", U32_MAX);
 100         if (priv->bpmp_bus_id == U32_MAX) {
 101                 debug("%s: could not parse nvidia,bpmp-bus-id\n", __func__);
 102                 return -EINVAL;
 103         }
 104
 105         return 0;
 106 }
 107
 108 static const struct dm_i2c_ops tegra186_bpmp_i2c_ops = {
 109         .xfer = tegra186_bpmp_i2c_xfer,
 110         .probe_chip = tegra186_bpmp_probe_chip,
 111 };
 112
 113 static const struct udevice_id tegra186_bpmp_i2c_ids[] = {
 114         { .compatible = "nvidia,tegra186-bpmp-i2c" },
 115         { }
 116 };
 117
 118 U_BOOT_DRIVER(i2c_gpio) = {
 119         .name   = "tegra186_bpmp_i2c",
 120         .id     = UCLASS_I2C,
 121         .of_match = tegra186_bpmp_i2c_ids,
 122         .probe  = tegra186_bpmp_i2c_probe,
 123         .priv_auto_alloc_size = sizeof(struct tegra186_bpmp_i2c),
 124         .ops    = &tegra186_bpmp_i2c_ops,
 125 };