drivers/spi/spi-altera-platform.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Altera SPI driver
   4  *
   5  * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
   6  *
   7  * Based on spi_s3c24xx.c, which is:
   8  * Copyright (c) 2006 Ben Dooks
   9  * Copyright (c) 2006 Simtec Electronics
  10  *      Ben Dooks <ben@simtec.co.uk>
  11  */
  12
  13 #include <linux/interrupt.h>
  14 #include <linux/errno.h>
  15 #include <linux/module.h>
  16 #include <linux/platform_device.h>
  17 #include <linux/spi/altera.h>
  18 #include <linux/spi/spi.h>
  19 #include <linux/io.h>
  20 #include <linux/of.h>
  21
  22 #define DRV_NAME "spi_altera"
  23
  24 enum altera_spi_type {
  25         ALTERA_SPI_TYPE_UNKNOWN,
  26         ALTERA_SPI_TYPE_SUBDEV,
  27 };
  28
  29 static const struct regmap_config spi_altera_config = {
  30         .reg_bits = 32,
  31         .reg_stride = 4,
  32         .val_bits = 32,
  33         .fast_io = true,
  34 };
  35
  36 static int altera_spi_probe(struct platform_device *pdev)
  37 {
  38         const struct platform_device_id *platid = platform_get_device_id(pdev);
  39         struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev);
  40         enum altera_spi_type type = ALTERA_SPI_TYPE_UNKNOWN;
  41         struct altera_spi *hw;
  42         struct spi_master *master;
  43         int err = -ENODEV;
  44         u16 i;
  45
  46         master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
  47         if (!master)
  48                 return err;
  49
  50         /* setup the master state. */
  51         master->bus_num = pdev->id;
  52
  53         if (pdata) {
  54                 if (pdata->num_chipselect > ALTERA_SPI_MAX_CS) {
  55                         dev_err(&pdev->dev,
  56                                 "Invalid number of chipselect: %u\n",
  57                                 pdata->num_chipselect);
  58                         err = -EINVAL;
  59                         goto exit;
  60                 }
  61
  62                 master->num_chipselect = pdata->num_chipselect;
  63                 master->mode_bits = pdata->mode_bits;
  64                 master->bits_per_word_mask = pdata->bits_per_word_mask;
  65         } else {
  66                 master->num_chipselect = 16;
  67                 master->mode_bits = SPI_CS_HIGH;
  68                 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16);
  69         }
  70
  71         master->dev.of_node = pdev->dev.of_node;
  72
  73         hw = spi_master_get_devdata(master);
  74         hw->dev = &pdev->dev;
  75
  76         if (platid)
  77                 type = platid->driver_data;
  78
  79         /* find and map our resources */
  80         if (type == ALTERA_SPI_TYPE_SUBDEV) {
  81                 struct resource *regoff;
  82
  83                 hw->regmap = dev_get_regmap(pdev->dev.parent, NULL);
  84                 if (!hw->regmap) {
  85                         dev_err(&pdev->dev, "get regmap failed\n");
  86                         goto exit;
  87                 }
  88
  89                 regoff = platform_get_resource(pdev, IORESOURCE_REG, 0);
  90                 if (regoff)
  91                         hw->regoff = regoff->start;
  92         } else {
  93                 void __iomem *res;
  94
  95                 res = devm_platform_ioremap_resource(pdev, 0);
  96                 if (IS_ERR(res)) {
  97                         err = PTR_ERR(res);
  98                         goto exit;
  99                 }
 100
 101                 hw->regmap = devm_regmap_init_mmio(&pdev->dev, res,
 102                                                    &spi_altera_config);
 103                 if (IS_ERR(hw->regmap)) {
 104                         dev_err(&pdev->dev, "regmap mmio init failed\n");
 105                         err = PTR_ERR(hw->regmap);
 106                         goto exit;
 107                 }
 108         }
 109
 110         altera_spi_init_master(master);
 111
 112         /* irq is optional */
 113         hw->irq = platform_get_irq(pdev, 0);
 114         if (hw->irq >= 0) {
 115                 err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0,
 116                                        pdev->name, master);
 117                 if (err)
 118                         goto exit;
 119         }
 120
 121         err = devm_spi_register_master(&pdev->dev, master);
 122         if (err)
 123                 goto exit;
 124
 125         if (pdata) {
 126                 for (i = 0; i < pdata->num_devices; i++) {
 127                         if (!spi_new_device(master, pdata->devices + i))
 128                                 dev_warn(&pdev->dev,
 129                                          "unable to create SPI device: %s\n",
 130                                          pdata->devices[i].modalias);
 131                 }
 132         }
 133
 134         dev_info(&pdev->dev, "regoff %u, irq %d\n", hw->regoff, hw->irq);
 135
 136         return 0;
 137 exit:
 138         spi_master_put(master);
 139         return err;
 140 }
 141
 142 #ifdef CONFIG_OF
 143 static const struct of_device_id altera_spi_match[] = {
 144         { .compatible = "ALTR,spi-1.0", },
 145         { .compatible = "altr,spi-1.0", },
 146         {},
 147 };
 148 MODULE_DEVICE_TABLE(of, altera_spi_match);
 149 #endif /* CONFIG_OF */
 150
 151 static const struct platform_device_id altera_spi_ids[] = {
 152         { DRV_NAME,             ALTERA_SPI_TYPE_UNKNOWN },
 153         { "subdev_spi_altera",  ALTERA_SPI_TYPE_SUBDEV },
 154         { }
 155 };
 156 MODULE_DEVICE_TABLE(platform, altera_spi_ids);
 157
 158 static struct platform_driver altera_spi_driver = {
 159         .probe = altera_spi_probe,
 160         .driver = {
 161                 .name = DRV_NAME,
 162                 .pm = NULL,
 163                 .of_match_table = of_match_ptr(altera_spi_match),
 164         },
 165         .id_table       = altera_spi_ids,
 166 };
 167 module_platform_driver(altera_spi_driver);
 168
 169 MODULE_DESCRIPTION("Altera SPI driver");
 170 MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
 171 MODULE_LICENSE("GPL");
 172 MODULE_ALIAS("platform:" DRV_NAME);