linux/drivers/bus/imx-weim.c
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   1/*
   2 * EIM driver for Freescale's i.MX chips
   3 *
   4 * Copyright (C) 2013 Freescale Semiconductor, Inc.
   5 *
   6 * This file is licensed under the terms of the GNU General Public
   7 * License version 2. This program is licensed "as is" without any
   8 * warranty of any kind, whether express or implied.
   9 */
  10#include <linux/module.h>
  11#include <linux/clk.h>
  12#include <linux/io.h>
  13#include <linux/of_device.h>
  14#include <linux/mfd/syscon.h>
  15#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
  16#include <linux/regmap.h>
  17
  18struct imx_weim_devtype {
  19        unsigned int    cs_count;
  20        unsigned int    cs_regs_count;
  21        unsigned int    cs_stride;
  22};
  23
  24static const struct imx_weim_devtype imx1_weim_devtype = {
  25        .cs_count       = 6,
  26        .cs_regs_count  = 2,
  27        .cs_stride      = 0x08,
  28};
  29
  30static const struct imx_weim_devtype imx27_weim_devtype = {
  31        .cs_count       = 6,
  32        .cs_regs_count  = 3,
  33        .cs_stride      = 0x10,
  34};
  35
  36static const struct imx_weim_devtype imx50_weim_devtype = {
  37        .cs_count       = 4,
  38        .cs_regs_count  = 6,
  39        .cs_stride      = 0x18,
  40};
  41
  42static const struct imx_weim_devtype imx51_weim_devtype = {
  43        .cs_count       = 6,
  44        .cs_regs_count  = 6,
  45        .cs_stride      = 0x18,
  46};
  47
  48static const struct of_device_id weim_id_table[] = {
  49        /* i.MX1/21 */
  50        { .compatible = "fsl,imx1-weim", .data = &imx1_weim_devtype, },
  51        /* i.MX25/27/31/35 */
  52        { .compatible = "fsl,imx27-weim", .data = &imx27_weim_devtype, },
  53        /* i.MX50/53/6Q */
  54        { .compatible = "fsl,imx50-weim", .data = &imx50_weim_devtype, },
  55        { .compatible = "fsl,imx6q-weim", .data = &imx50_weim_devtype, },
  56        /* i.MX51 */
  57        { .compatible = "fsl,imx51-weim", .data = &imx51_weim_devtype, },
  58        { }
  59};
  60MODULE_DEVICE_TABLE(of, weim_id_table);
  61
  62static int __init imx_weim_gpr_setup(struct platform_device *pdev)
  63{
  64        struct device_node *np = pdev->dev.of_node;
  65        struct property *prop;
  66        const __be32 *p;
  67        struct regmap *gpr;
  68        u32 gprvals[4] = {
  69                05,     /* CS0(128M) CS1(0M)  CS2(0M)  CS3(0M)  */
  70                033,    /* CS0(64M)  CS1(64M) CS2(0M)  CS3(0M)  */
  71                0113,   /* CS0(64M)  CS1(32M) CS2(32M) CS3(0M)  */
  72                01111,  /* CS0(32M)  CS1(32M) CS2(32M) CS3(32M) */
  73        };
  74        u32 gprval = 0;
  75        u32 val;
  76        int cs = 0;
  77        int i = 0;
  78
  79        gpr = syscon_regmap_lookup_by_phandle(np, "fsl,weim-cs-gpr");
  80        if (IS_ERR(gpr)) {
  81                dev_dbg(&pdev->dev, "failed to find weim-cs-gpr\n");
  82                return 0;
  83        }
  84
  85        of_property_for_each_u32(np, "ranges", prop, p, val) {
  86                if (i % 4 == 0) {
  87                        cs = val;
  88                } else if (i % 4 == 3 && val) {
  89                        val = (val / SZ_32M) | 1;
  90                        gprval |= val << cs * 3;
  91                }
  92                i++;
  93        }
  94
  95        if (i == 0 || i % 4)
  96                goto err;
  97
  98        for (i = 0; i < ARRAY_SIZE(gprvals); i++) {
  99                if (gprval == gprvals[i]) {
 100                        /* Found it. Set up IOMUXC_GPR1[11:0] with it. */
 101                        regmap_update_bits(gpr, IOMUXC_GPR1, 0xfff, gprval);
 102                        return 0;
 103                }
 104        }
 105
 106err:
 107        dev_err(&pdev->dev, "Invalid 'ranges' configuration\n");
 108        return -EINVAL;
 109}
 110
 111/* Parse and set the timing for this device. */
 112static int __init weim_timing_setup(struct device_node *np, void __iomem *base,
 113                                    const struct imx_weim_devtype *devtype)
 114{
 115        u32 cs_idx, value[devtype->cs_regs_count];
 116        int i, ret;
 117
 118        /* get the CS index from this child node's "reg" property. */
 119        ret = of_property_read_u32(np, "reg", &cs_idx);
 120        if (ret)
 121                return ret;
 122
 123        if (cs_idx >= devtype->cs_count)
 124                return -EINVAL;
 125
 126        ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
 127                                         value, devtype->cs_regs_count);
 128        if (ret)
 129                return ret;
 130
 131        /* set the timing for WEIM */
 132        for (i = 0; i < devtype->cs_regs_count; i++)
 133                writel(value[i], base + cs_idx * devtype->cs_stride + i * 4);
 134
 135        return 0;
 136}
 137
 138static int __init weim_parse_dt(struct platform_device *pdev,
 139                                void __iomem *base)
 140{
 141        const struct of_device_id *of_id = of_match_device(weim_id_table,
 142                                                           &pdev->dev);
 143        const struct imx_weim_devtype *devtype = of_id->data;
 144        struct device_node *child;
 145        int ret, have_child = 0;
 146
 147        if (devtype == &imx50_weim_devtype) {
 148                ret = imx_weim_gpr_setup(pdev);
 149                if (ret)
 150                        return ret;
 151        }
 152
 153        for_each_available_child_of_node(pdev->dev.of_node, child) {
 154                if (!child->name)
 155                        continue;
 156
 157                ret = weim_timing_setup(child, base, devtype);
 158                if (ret)
 159                        dev_warn(&pdev->dev, "%pOF set timing failed.\n",
 160                                child);
 161                else
 162                        have_child = 1;
 163        }
 164
 165        if (have_child)
 166                ret = of_platform_default_populate(pdev->dev.of_node,
 167                                                   NULL, &pdev->dev);
 168        if (ret)
 169                dev_err(&pdev->dev, "%pOF fail to create devices.\n",
 170                        pdev->dev.of_node);
 171        return ret;
 172}
 173
 174static int __init weim_probe(struct platform_device *pdev)
 175{
 176        struct resource *res;
 177        struct clk *clk;
 178        void __iomem *base;
 179        int ret;
 180
 181        /* get the resource */
 182        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 183        base = devm_ioremap_resource(&pdev->dev, res);
 184        if (IS_ERR(base))
 185                return PTR_ERR(base);
 186
 187        /* get the clock */
 188        clk = devm_clk_get(&pdev->dev, NULL);
 189        if (IS_ERR(clk))
 190                return PTR_ERR(clk);
 191
 192        ret = clk_prepare_enable(clk);
 193        if (ret)
 194                return ret;
 195
 196        /* parse the device node */
 197        ret = weim_parse_dt(pdev, base);
 198        if (ret)
 199                clk_disable_unprepare(clk);
 200        else
 201                dev_info(&pdev->dev, "Driver registered.\n");
 202
 203        return ret;
 204}
 205
 206static struct platform_driver weim_driver = {
 207        .driver = {
 208                .name           = "imx-weim",
 209                .of_match_table = weim_id_table,
 210        },
 211};
 212module_platform_driver_probe(weim_driver, weim_probe);
 213
 214MODULE_AUTHOR("Freescale Semiconductor Inc.");
 215MODULE_DESCRIPTION("i.MX EIM Controller Driver");
 216MODULE_LICENSE("GPL");
 217