drivers/mfd/rk8xx-spi.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Rockchip RK806 Core (SPI) driver
   4  *
   5  * Copyright (c) 2021 Rockchip Electronics Co., Ltd.
   6  * Copyright (c) 2023 Collabora Ltd.
   7  *
   8  * Author: Xu Shengfei <xsf@rock-chips.com>
   9  * Author: Sebastian Reichel <sebastian.reichel@collabora.com>
  10  */
  11
  12 #include <linux/interrupt.h>
  13 #include <linux/mfd/core.h>
  14 #include <linux/mfd/rk808.h>
  15 #include <linux/module.h>
  16 #include <linux/regmap.h>
  17 #include <linux/spi/spi.h>
  18
  19 #define RK806_ADDR_SIZE 2
  20 #define RK806_CMD_WITH_SIZE(CMD, VALUE_BYTES) \
  21         (RK806_CMD_##CMD | RK806_CMD_CRC_DIS | (VALUE_BYTES - 1))
  22
  23 static const struct regmap_range rk806_volatile_ranges[] = {
  24         regmap_reg_range(RK806_POWER_EN0, RK806_POWER_EN5),
  25         regmap_reg_range(RK806_DVS_START_CTRL, RK806_INT_MSK1),
  26 };
  27
  28 static const struct regmap_access_table rk806_volatile_table = {
  29         .yes_ranges = rk806_volatile_ranges,
  30         .n_yes_ranges = ARRAY_SIZE(rk806_volatile_ranges),
  31 };
  32
  33 static const struct regmap_config rk806_regmap_config_spi = {
  34         .reg_bits = 16,
  35         .val_bits = 8,
  36         .max_register = RK806_BUCK_RSERVE_REG5,
  37         .cache_type = REGCACHE_RBTREE,
  38         .volatile_table = &rk806_volatile_table,
  39 };
  40
  41 static int rk806_spi_bus_write(void *context, const void *vdata, size_t count)
  42 {
  43         struct device *dev = context;
  44         struct spi_device *spi = to_spi_device(dev);
  45         struct spi_transfer xfer[2] = { 0 };
  46         /* data and thus count includes the register address */
  47         size_t val_size = count - RK806_ADDR_SIZE;
  48         char cmd;
  49
  50         if (val_size < 1 || val_size > (RK806_CMD_LEN_MSK + 1))
  51                 return -EINVAL;
  52
  53         cmd = RK806_CMD_WITH_SIZE(WRITE, val_size);
  54
  55         xfer[0].tx_buf = &cmd;
  56         xfer[0].len = sizeof(cmd);
  57         xfer[1].tx_buf = vdata;
  58         xfer[1].len = count;
  59
  60         return spi_sync_transfer(spi, xfer, ARRAY_SIZE(xfer));
  61 }
  62
  63 static int rk806_spi_bus_read(void *context, const void *vreg, size_t reg_size,
  64                               void *val, size_t val_size)
  65 {
  66         struct device *dev = context;
  67         struct spi_device *spi = to_spi_device(dev);
  68         char txbuf[3] = { 0 };
  69
  70         if (reg_size != RK806_ADDR_SIZE ||
  71             val_size < 1 || val_size > (RK806_CMD_LEN_MSK + 1))
  72                 return -EINVAL;
  73
  74         /* TX buffer contains command byte followed by two address bytes */
  75         txbuf[0] = RK806_CMD_WITH_SIZE(READ, val_size);
  76         memcpy(txbuf+1, vreg, reg_size);
  77
  78         return spi_write_then_read(spi, txbuf, sizeof(txbuf), val, val_size);
  79 }
  80
  81 static const struct regmap_bus rk806_regmap_bus_spi = {
  82         .write = rk806_spi_bus_write,
  83         .read = rk806_spi_bus_read,
  84         .reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
  85 };
  86
  87 static int rk8xx_spi_probe(struct spi_device *spi)
  88 {
  89         struct regmap *regmap;
  90
  91         regmap = devm_regmap_init(&spi->dev, &rk806_regmap_bus_spi,
  92                                   &spi->dev, &rk806_regmap_config_spi);
  93         if (IS_ERR(regmap))
  94                 return dev_err_probe(&spi->dev, PTR_ERR(regmap),
  95                                      "Failed to init regmap\n");
  96
  97         return rk8xx_probe(&spi->dev, RK806_ID, spi->irq, regmap);
  98 }
  99
 100 static const struct of_device_id rk8xx_spi_of_match[] = {
 101         { .compatible = "rockchip,rk806", },
 102         { }
 103 };
 104 MODULE_DEVICE_TABLE(of, rk8xx_spi_of_match);
 105
 106 static const struct spi_device_id rk8xx_spi_id_table[] = {
 107         { "rk806", 0 },
 108         { }
 109 };
 110 MODULE_DEVICE_TABLE(spi, rk8xx_spi_id_table);
 111
 112 static struct spi_driver rk8xx_spi_driver = {
 113         .driver         = {
 114                 .name   = "rk8xx-spi",
 115                 .of_match_table = rk8xx_spi_of_match,
 116         },
 117         .probe          = rk8xx_spi_probe,
 118         .id_table       = rk8xx_spi_id_table,
 119 };
 120 module_spi_driver(rk8xx_spi_driver);
 121
 122 MODULE_AUTHOR("Xu Shengfei <xsf@rock-chips.com>");
 123 MODULE_DESCRIPTION("RK8xx SPI PMIC driver");
 124 MODULE_LICENSE("GPL");