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 <log.h>
  10 #include <misc.h>
  11 #include <asm/arch-tegra/bpmp_abi.h>
  12 #include <asm/global_data.h>
  13 #include <linux/bitops.h>
  14
  15 DECLARE_GLOBAL_DATA_PTR;
  16
  17 struct tegra186_bpmp_i2c {
  18         uint32_t bpmp_bus_id;
  19 };
  20
  21 static inline void serialize_u16(uint8_t **p, uint16_t val)
  22 {
  23         (*p)[0] = val & 0xff;
  24         (*p)[1] = val >> 8;
  25         (*p) += 2;
  26 }
  27
  28 /* These just happen to have the same values as I2C_M_* and SERIALI2C_* */
  29 #define SUPPORTED_FLAGS \
  30         (I2C_M_TEN | \
  31         I2C_M_RD | \
  32         I2C_M_STOP | \
  33         I2C_M_NOSTART | \
  34         I2C_M_REV_DIR_ADDR | \
  35         I2C_M_IGNORE_NAK | \
  36         I2C_M_NO_RD_ACK | \
  37         I2C_M_RECV_LEN)
  38
  39 static int tegra186_bpmp_i2c_xfer(struct udevice *dev, struct i2c_msg *msg,
  40                                   int nmsgs)
  41 {
  42         struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
  43         struct mrq_i2c_request req;
  44         struct mrq_i2c_response resp;
  45         uint8_t *p;
  46         int left, i, ret;
  47
  48         req.cmd = CMD_I2C_XFER;
  49         req.xfer.bus_id = priv->bpmp_bus_id;
  50         p = &req.xfer.data_buf[0];
  51         left = ARRAY_SIZE(req.xfer.data_buf);
  52         for (i = 0; i < nmsgs; i++) {
  53                 int len = 6;
  54                 if (!(msg[i].flags & I2C_M_RD))
  55                         len += msg[i].len;
  56                 if ((len >= BIT(16)) || (len > left))
  57                         return -ENOSPC;
  58
  59                 if (msg[i].flags & ~SUPPORTED_FLAGS)
  60                         return -EINVAL;
  61
  62                 serialize_u16(&p, msg[i].addr);
  63                 serialize_u16(&p, msg[i].flags);
  64                 serialize_u16(&p, msg[i].len);
  65                 if (!(msg[i].flags & I2C_M_RD)) {
  66                         memcpy(p, msg[i].buf, msg[i].len);
  67                         p += msg[i].len;
  68                 }
  69         }
  70         req.xfer.data_size = p - &req.xfer.data_buf[0];
  71
  72         ret = misc_call(dev->parent, MRQ_I2C, &req, sizeof(req), &resp,
  73                         sizeof(resp));
  74         if (ret < 0)
  75                 return ret;
  76
  77         p = &resp.xfer.data_buf[0];
  78         left = resp.xfer.data_size;
  79         if (left > ARRAY_SIZE(resp.xfer.data_buf))
  80                 return -EINVAL;
  81         for (i = 0; i < nmsgs; i++) {
  82                 if (msg[i].flags & I2C_M_RD) {
  83                         memcpy(msg[i].buf, p, msg[i].len);
  84                         p += msg[i].len;
  85                 }
  86         }
  87
  88         return 0;
  89 }
  90
  91 static int tegra186_bpmp_probe_chip(struct udevice *bus, uint chip_addr,
  92                                     uint chip_flags)
  93 {
  94         return 0;
  95 }
  96
  97 static int tegra186_bpmp_i2c_probe(struct udevice *dev)
  98 {
  99         struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
 100
 101         priv->bpmp_bus_id = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
 102                                             "nvidia,bpmp-bus-id", U32_MAX);
 103         if (priv->bpmp_bus_id == U32_MAX) {
 104                 debug("%s: could not parse nvidia,bpmp-bus-id\n", __func__);
 105                 return -EINVAL;
 106         }
 107
 108         return 0;
 109 }
 110
 111 static const struct dm_i2c_ops tegra186_bpmp_i2c_ops = {
 112         .xfer = tegra186_bpmp_i2c_xfer,
 113         .probe_chip = tegra186_bpmp_probe_chip,
 114 };
 115
 116 static const struct udevice_id tegra186_bpmp_i2c_ids[] = {
 117         { .compatible = "nvidia,tegra186-bpmp-i2c" },
 118         { }
 119 };
 120
 121 U_BOOT_DRIVER(i2c_gpio) = {
 122         .name   = "tegra186_bpmp_i2c",
 123         .id     = UCLASS_I2C,
 124         .of_match = tegra186_bpmp_i2c_ids,
 125         .probe  = tegra186_bpmp_i2c_probe,
 126         .priv_auto      = sizeof(struct tegra186_bpmp_i2c),
 127         .ops    = &tegra186_bpmp_i2c_ops,
 128 };