drivers/tty/serial/sc16is7xx_spi.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /* SC16IS7xx SPI interface driver */
   3
   4 #include <linux/dev_printk.h>
   5 #include <linux/mod_devicetable.h>
   6 #include <linux/module.h>
   7 #include <linux/regmap.h>
   8 #include <linux/spi/spi.h>
   9 #include <linux/string.h>
  10 #include <linux/units.h>
  11
  12 #include "sc16is7xx.h"
  13
  14 /* SPI definitions */
  15 #define SC16IS7XX_SPI_READ_BIT  BIT(7)
  16
  17 static int sc16is7xx_spi_probe(struct spi_device *spi)
  18 {
  19         const struct sc16is7xx_devtype *devtype;
  20         struct regmap *regmaps[SC16IS7XX_MAX_PORTS];
  21         struct regmap_config regcfg;
  22         unsigned int i;
  23         int ret;
  24
  25         /* Setup SPI bus */
  26         spi->bits_per_word      = 8;
  27         /* For all variants, only mode 0 is supported */
  28         if ((spi->mode & SPI_MODE_X_MASK) != SPI_MODE_0)
  29                 return dev_err_probe(&spi->dev, -EINVAL, "Unsupported SPI mode\n");
  30
  31         spi->mode               = spi->mode ? : SPI_MODE_0;
  32         spi->max_speed_hz       = spi->max_speed_hz ? : 4 * HZ_PER_MHZ;
  33         ret = spi_setup(spi);
  34         if (ret)
  35                 return ret;
  36
  37         devtype = spi_get_device_match_data(spi);
  38         if (!devtype)
  39                 return dev_err_probe(&spi->dev, -ENODEV, "Failed to match device\n");
  40
  41         memcpy(&regcfg, &sc16is7xx_regcfg, sizeof(struct regmap_config));
  42
  43         for (i = 0; i < devtype->nr_uart; i++) {
  44                 regcfg.name = sc16is7xx_regmap_name(i);
  45                 /*
  46                  * If read_flag_mask is 0, the regmap code sets it to a default
  47                  * of 0x80. Since we specify our own mask, we must add the READ
  48                  * bit ourselves:
  49                  */
  50                 regcfg.read_flag_mask = sc16is7xx_regmap_port_mask(i) |
  51                         SC16IS7XX_SPI_READ_BIT;
  52                 regcfg.write_flag_mask = sc16is7xx_regmap_port_mask(i);
  53                 regmaps[i] = devm_regmap_init_spi(spi, &regcfg);
  54         }
  55
  56         return sc16is7xx_probe(&spi->dev, devtype, regmaps, spi->irq);
  57 }
  58
  59 static void sc16is7xx_spi_remove(struct spi_device *spi)
  60 {
  61         sc16is7xx_remove(&spi->dev);
  62 }
  63
  64 static const struct spi_device_id sc16is7xx_spi_id_table[] = {
  65         { "sc16is74x",  (kernel_ulong_t)&sc16is74x_devtype, },
  66         { "sc16is740",  (kernel_ulong_t)&sc16is74x_devtype, },
  67         { "sc16is741",  (kernel_ulong_t)&sc16is74x_devtype, },
  68         { "sc16is750",  (kernel_ulong_t)&sc16is750_devtype, },
  69         { "sc16is752",  (kernel_ulong_t)&sc16is752_devtype, },
  70         { "sc16is760",  (kernel_ulong_t)&sc16is760_devtype, },
  71         { "sc16is762",  (kernel_ulong_t)&sc16is762_devtype, },
  72         { }
  73 };
  74 MODULE_DEVICE_TABLE(spi, sc16is7xx_spi_id_table);
  75
  76 static struct spi_driver sc16is7xx_spi_driver = {
  77         .driver = {
  78                 .name           = SC16IS7XX_NAME,
  79                 .of_match_table = sc16is7xx_dt_ids,
  80         },
  81         .probe          = sc16is7xx_spi_probe,
  82         .remove         = sc16is7xx_spi_remove,
  83         .id_table       = sc16is7xx_spi_id_table,
  84 };
  85
  86 module_spi_driver(sc16is7xx_spi_driver);
  87
  88 MODULE_LICENSE("GPL");
  89 MODULE_DESCRIPTION("SC16IS7xx SPI interface driver");
  90 MODULE_IMPORT_NS(SERIAL_NXP_SC16IS7XX);