drivers/i2c/tegra186_bpmp_i2c.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2016, NVIDIA CORPORATION.
   4  */
   5
   6 #include <dm.h>
   7 #include <i2c.h>
   8 #include <log.h>
   9 #include <misc.h>
  10 #include <asm/arch-tegra/bpmp_abi.h>
  11 #include <asm/global_data.h>
  12 #include <linux/bitops.h>
  13
  14 DECLARE_GLOBAL_DATA_PTR;
  15
  16 struct tegra186_bpmp_i2c {
  17         uint32_t bpmp_bus_id;
  18 };
  19
  20 static inline void serialize_u16(uint8_t **p, uint16_t val)
  21 {
  22         (*p)[0] = val & 0xff;
  23         (*p)[1] = val >> 8;
  24         (*p) += 2;
  25 }
  26
  27 /* These just happen to have the same values as I2C_M_* and SERIALI2C_* */
  28 #define SUPPORTED_FLAGS \
  29         (I2C_M_TEN | \
  30         I2C_M_RD | \
  31         I2C_M_STOP | \
  32         I2C_M_NOSTART | \
  33         I2C_M_REV_DIR_ADDR | \
  34         I2C_M_IGNORE_NAK | \
  35         I2C_M_NO_RD_ACK | \
  36         I2C_M_RECV_LEN)
  37
  38 static int tegra186_bpmp_i2c_xfer(struct udevice *dev, struct i2c_msg *msg,
  39                                   int nmsgs)
  40 {
  41         struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
  42         struct mrq_i2c_request req;
  43         struct mrq_i2c_response resp;
  44         uint8_t *p;
  45         int left, i, ret;
  46
  47         req.cmd = CMD_I2C_XFER;
  48         req.xfer.bus_id = priv->bpmp_bus_id;
  49         p = &req.xfer.data_buf[0];
  50         left = ARRAY_SIZE(req.xfer.data_buf);
  51         for (i = 0; i < nmsgs; i++) {
  52                 int len = 6;
  53                 if (!(msg[i].flags & I2C_M_RD))
  54                         len += msg[i].len;
  55                 if ((len >= BIT(16)) || (len > left))
  56                         return -ENOSPC;
  57
  58                 if (msg[i].flags & ~SUPPORTED_FLAGS)
  59                         return -EINVAL;
  60
  61                 serialize_u16(&p, msg[i].addr);
  62                 serialize_u16(&p, msg[i].flags);
  63                 serialize_u16(&p, msg[i].len);
  64                 if (!(msg[i].flags & I2C_M_RD)) {
  65                         memcpy(p, msg[i].buf, msg[i].len);
  66                         p += msg[i].len;
  67                 }
  68         }
  69         req.xfer.data_size = p - &req.xfer.data_buf[0];
  70
  71         ret = misc_call(dev->parent, MRQ_I2C, &req, sizeof(req), &resp,
  72                         sizeof(resp));
  73         if (ret < 0)
  74                 return ret;
  75
  76         p = &resp.xfer.data_buf[0];
  77         left = resp.xfer.data_size;
  78         if (left > ARRAY_SIZE(resp.xfer.data_buf))
  79                 return -EINVAL;
  80         for (i = 0; i < nmsgs; i++) {
  81                 if (msg[i].flags & I2C_M_RD) {
  82                         memcpy(msg[i].buf, p, msg[i].len);
  83                         p += msg[i].len;
  84                 }
  85         }
  86
  87         return 0;
  88 }
  89
  90 static int tegra186_bpmp_probe_chip(struct udevice *bus, uint chip_addr,
  91                                     uint chip_flags)
  92 {
  93         return 0;
  94 }
  95
  96 static int tegra186_bpmp_i2c_probe(struct udevice *dev)
  97 {
  98         struct tegra186_bpmp_i2c *priv = dev_get_priv(dev);
  99
 100         priv->bpmp_bus_id = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
 101                                             "nvidia,bpmp-bus-id", U32_MAX);
 102         if (priv->bpmp_bus_id == U32_MAX) {
 103                 debug("%s: could not parse nvidia,bpmp-bus-id\n", __func__);
 104                 return -EINVAL;
 105         }
 106
 107         return 0;
 108 }
 109
 110 static const struct dm_i2c_ops tegra186_bpmp_i2c_ops = {
 111         .xfer = tegra186_bpmp_i2c_xfer,
 112         .probe_chip = tegra186_bpmp_probe_chip,
 113 };
 114
 115 static const struct udevice_id tegra186_bpmp_i2c_ids[] = {
 116         { .compatible = "nvidia,tegra186-bpmp-i2c" },
 117         { }
 118 };
 119
 120 U_BOOT_DRIVER(i2c_gpio) = {
 121         .name   = "tegra186_bpmp_i2c",
 122         .id     = UCLASS_I2C,
 123         .of_match = tegra186_bpmp_i2c_ids,
 124         .probe  = tegra186_bpmp_i2c_probe,
 125         .priv_auto      = sizeof(struct tegra186_bpmp_i2c),
 126         .ops    = &tegra186_bpmp_i2c_ops,
 127 };