LXR linux/drivers/spi/spi-dw-mmio.c

   1/*
   2 * Memory-mapped interface driver for DW SPI Core
   3 *
   4 * Copyright (c) 2010, Octasic semiconductor.
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms and conditions of the GNU General Public License,
   8 * version 2, as published by the Free Software Foundation.
   9 */
  10
  11#include <linux/clk.h>
  12#include <linux/err.h>
  13#include <linux/interrupt.h>
  14#include <linux/platform_device.h>
  15#include <linux/slab.h>
  16#include <linux/spi/spi.h>
  17#include <linux/scatterlist.h>
  18#include <linux/module.h>
  19#include <linux/of.h>
  20#include <linux/of_gpio.h>
  21#include <linux/of_platform.h>
  22#include <linux/property.h>
  23
  24#include "spi-dw.h"
  25
  26#define DRIVER_NAME "dw_spi_mmio"
  27
  28struct dw_spi_mmio {
  29        struct dw_spi  dws;
  30        struct clk     *clk;
  31};
  32
  33static int dw_spi_mmio_probe(struct platform_device *pdev)
  34{
  35        struct dw_spi_mmio *dwsmmio;
  36        struct dw_spi *dws;
  37        struct resource *mem;
  38        int ret;
  39        int num_cs;
  40
  41        dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio),
  42                        GFP_KERNEL);
  43        if (!dwsmmio)
  44                return -ENOMEM;
  45
  46        dws = &dwsmmio->dws;
  47
  48        /* Get basic io resource and map it */
  49        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  50        dws->regs = devm_ioremap_resource(&pdev->dev, mem);
  51        if (IS_ERR(dws->regs)) {
  52                dev_err(&pdev->dev, "SPI region map failed\n");
  53                return PTR_ERR(dws->regs);
  54        }
  55
  56        dws->irq = platform_get_irq(pdev, 0);
  57        if (dws->irq < 0) {
  58                dev_err(&pdev->dev, "no irq resource?\n");
  59                return dws->irq; /* -ENXIO */
  60        }
  61
  62        dwsmmio->clk = devm_clk_get(&pdev->dev, NULL);
  63        if (IS_ERR(dwsmmio->clk))
  64                return PTR_ERR(dwsmmio->clk);
  65        ret = clk_prepare_enable(dwsmmio->clk);
  66        if (ret)
  67                return ret;
  68
  69        dws->bus_num = pdev->id;
  70
  71        dws->max_freq = clk_get_rate(dwsmmio->clk);
  72
  73        device_property_read_u32(&pdev->dev, "reg-io-width", &dws->reg_io_width);
  74
  75        num_cs = 4;
  76
  77        device_property_read_u32(&pdev->dev, "num-cs", &num_cs);
  78
  79        dws->num_cs = num_cs;
  80
  81        if (pdev->dev.of_node) {
  82                int i;
  83
  84                for (i = 0; i < dws->num_cs; i++) {
  85                        int cs_gpio = of_get_named_gpio(pdev->dev.of_node,
  86                                        "cs-gpios", i);
  87
  88                        if (cs_gpio == -EPROBE_DEFER) {
  89                                ret = cs_gpio;
  90                                goto out;
  91                        }
  92
  93                        if (gpio_is_valid(cs_gpio)) {
  94                                ret = devm_gpio_request(&pdev->dev, cs_gpio,
  95                                                dev_name(&pdev->dev));
  96                                if (ret)
  97                                        goto out;
  98                        }
  99                }
 100        }
 101
 102        ret = dw_spi_add_host(&pdev->dev, dws);
 103        if (ret)
 104                goto out;
 105
 106        platform_set_drvdata(pdev, dwsmmio);
 107        return 0;
 108
 109out:
 110        clk_disable_unprepare(dwsmmio->clk);
 111        return ret;
 112}
 113
 114static int dw_spi_mmio_remove(struct platform_device *pdev)
 115{
 116        struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
 117
 118        dw_spi_remove_host(&dwsmmio->dws);
 119        clk_disable_unprepare(dwsmmio->clk);
 120
 121        return 0;
 122}
 123
 124static const struct of_device_id dw_spi_mmio_of_match[] = {
 125        { .compatible = "snps,dw-apb-ssi", },
 126        { /* end of table */}
 127};
 128MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
 129
 130static struct platform_driver dw_spi_mmio_driver = {
 131        .probe          = dw_spi_mmio_probe,
 132        .remove         = dw_spi_mmio_remove,
 133        .driver         = {
 134                .name   = DRIVER_NAME,
 135                .of_match_table = dw_spi_mmio_of_match,
 136        },
 137};
 138module_platform_driver(dw_spi_mmio_driver);
 139
 140MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
 141MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
 142MODULE_LICENSE("GPL v2");
 143