drivers/bus/imx-weim.c

   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
  18 struct imx_weim_devtype {
  19         unsigned int    cs_count;
  20         unsigned int    cs_regs_count;
  21         unsigned int    cs_stride;
  22 };
  23
  24 static const struct imx_weim_devtype imx1_weim_devtype = {
  25         .cs_count       = 6,
  26         .cs_regs_count  = 2,
  27         .cs_stride      = 0x08,
  28 };
  29
  30 static const struct imx_weim_devtype imx27_weim_devtype = {
  31         .cs_count       = 6,
  32         .cs_regs_count  = 3,
  33         .cs_stride      = 0x10,
  34 };
  35
  36 static const struct imx_weim_devtype imx50_weim_devtype = {
  37         .cs_count       = 4,
  38         .cs_regs_count  = 6,
  39         .cs_stride      = 0x18,
  40 };
  41
  42 static const struct imx_weim_devtype imx51_weim_devtype = {
  43         .cs_count       = 6,
  44         .cs_regs_count  = 6,
  45         .cs_stride      = 0x18,
  46 };
  47
  48 static 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 };
  60 MODULE_DEVICE_TABLE(of, weim_id_table);
  61
  62 static 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
 106 err:
 107         dev_err(&pdev->dev, "Invalid 'ranges' configuration\n");
 108         return -EINVAL;
 109 }
 110
 111 /* Parse and set the timing for this device. */
 112 static 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
 138 static 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_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, "%s set timing failed.\n",
 160                                 child->full_name);
 161                 else
 162                         have_child = 1;
 163         }
 164
 165         if (have_child)
 166                 ret = of_platform_populate(pdev->dev.of_node,
 167                                    of_default_bus_match_table,
 168                                    NULL, &pdev->dev);
 169         if (ret)
 170                 dev_err(&pdev->dev, "%s fail to create devices.\n",
 171                         pdev->dev.of_node->full_name);
 172         return ret;
 173 }
 174
 175 static int __init weim_probe(struct platform_device *pdev)
 176 {
 177         struct resource *res;
 178         struct clk *clk;
 179         void __iomem *base;
 180         int ret;
 181
 182         /* get the resource */
 183         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 184         base = devm_ioremap_resource(&pdev->dev, res);
 185         if (IS_ERR(base))
 186                 return PTR_ERR(base);
 187
 188         /* get the clock */
 189         clk = devm_clk_get(&pdev->dev, NULL);
 190         if (IS_ERR(clk))
 191                 return PTR_ERR(clk);
 192
 193         ret = clk_prepare_enable(clk);
 194         if (ret)
 195                 return ret;
 196
 197         /* parse the device node */
 198         ret = weim_parse_dt(pdev, base);
 199         if (ret)
 200                 clk_disable_unprepare(clk);
 201         else
 202                 dev_info(&pdev->dev, "Driver registered.\n");
 203
 204         return ret;
 205 }
 206
 207 static struct platform_driver weim_driver = {
 208         .driver = {
 209                 .name           = "imx-weim",
 210                 .of_match_table = weim_id_table,
 211         },
 212 };
 213 module_platform_driver_probe(weim_driver, weim_probe);
 214
 215 MODULE_AUTHOR("Freescale Semiconductor Inc.");
 216 MODULE_DESCRIPTION("i.MX EIM Controller Driver");
 217 MODULE_LICENSE("GPL");