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 #define MAX_CS_REGS_COUNT       6
  49
  50 static const struct of_device_id weim_id_table[] = {
  51         /* i.MX1/21 */
  52         { .compatible = "fsl,imx1-weim", .data = &imx1_weim_devtype, },
  53         /* i.MX25/27/31/35 */
  54         { .compatible = "fsl,imx27-weim", .data = &imx27_weim_devtype, },
  55         /* i.MX50/53/6Q */
  56         { .compatible = "fsl,imx50-weim", .data = &imx50_weim_devtype, },
  57         { .compatible = "fsl,imx6q-weim", .data = &imx50_weim_devtype, },
  58         /* i.MX51 */
  59         { .compatible = "fsl,imx51-weim", .data = &imx51_weim_devtype, },
  60         { }
  61 };
  62 MODULE_DEVICE_TABLE(of, weim_id_table);
  63
  64 static int __init imx_weim_gpr_setup(struct platform_device *pdev)
  65 {
  66         struct device_node *np = pdev->dev.of_node;
  67         struct property *prop;
  68         const __be32 *p;
  69         struct regmap *gpr;
  70         u32 gprvals[4] = {
  71                 05,     /* CS0(128M) CS1(0M)  CS2(0M)  CS3(0M)  */
  72                 033,    /* CS0(64M)  CS1(64M) CS2(0M)  CS3(0M)  */
  73                 0113,   /* CS0(64M)  CS1(32M) CS2(32M) CS3(0M)  */
  74                 01111,  /* CS0(32M)  CS1(32M) CS2(32M) CS3(32M) */
  75         };
  76         u32 gprval = 0;
  77         u32 val;
  78         int cs = 0;
  79         int i = 0;
  80
  81         gpr = syscon_regmap_lookup_by_phandle(np, "fsl,weim-cs-gpr");
  82         if (IS_ERR(gpr)) {
  83                 dev_dbg(&pdev->dev, "failed to find weim-cs-gpr\n");
  84                 return 0;
  85         }
  86
  87         of_property_for_each_u32(np, "ranges", prop, p, val) {
  88                 if (i % 4 == 0) {
  89                         cs = val;
  90                 } else if (i % 4 == 3 && val) {
  91                         val = (val / SZ_32M) | 1;
  92                         gprval |= val << cs * 3;
  93                 }
  94                 i++;
  95         }
  96
  97         if (i == 0 || i % 4)
  98                 goto err;
  99
 100         for (i = 0; i < ARRAY_SIZE(gprvals); i++) {
 101                 if (gprval == gprvals[i]) {
 102                         /* Found it. Set up IOMUXC_GPR1[11:0] with it. */
 103                         regmap_update_bits(gpr, IOMUXC_GPR1, 0xfff, gprval);
 104                         return 0;
 105                 }
 106         }
 107
 108 err:
 109         dev_err(&pdev->dev, "Invalid 'ranges' configuration\n");
 110         return -EINVAL;
 111 }
 112
 113 /* Parse and set the timing for this device. */
 114 static int __init weim_timing_setup(struct device_node *np, void __iomem *base,
 115                                     const struct imx_weim_devtype *devtype)
 116 {
 117         u32 cs_idx, value[MAX_CS_REGS_COUNT];
 118         int i, ret;
 119
 120         if (WARN_ON(devtype->cs_regs_count > MAX_CS_REGS_COUNT))
 121                 return -EINVAL;
 122
 123         /* get the CS index from this child node's "reg" property. */
 124         ret = of_property_read_u32(np, "reg", &cs_idx);
 125         if (ret)
 126                 return ret;
 127
 128         if (cs_idx >= devtype->cs_count)
 129                 return -EINVAL;
 130
 131         ret = of_property_read_u32_array(np, "fsl,weim-cs-timing",
 132                                          value, devtype->cs_regs_count);
 133         if (ret)
 134                 return ret;
 135
 136         /* set the timing for WEIM */
 137         for (i = 0; i < devtype->cs_regs_count; i++)
 138                 writel(value[i], base + cs_idx * devtype->cs_stride + i * 4);
 139
 140         return 0;
 141 }
 142
 143 static int __init weim_parse_dt(struct platform_device *pdev,
 144                                 void __iomem *base)
 145 {
 146         const struct of_device_id *of_id = of_match_device(weim_id_table,
 147                                                            &pdev->dev);
 148         const struct imx_weim_devtype *devtype = of_id->data;
 149         struct device_node *child;
 150         int ret, have_child = 0;
 151
 152         if (devtype == &imx50_weim_devtype) {
 153                 ret = imx_weim_gpr_setup(pdev);
 154                 if (ret)
 155                         return ret;
 156         }
 157
 158         for_each_available_child_of_node(pdev->dev.of_node, child) {
 159                 if (!child->name)
 160                         continue;
 161
 162                 ret = weim_timing_setup(child, base, devtype);
 163                 if (ret)
 164                         dev_warn(&pdev->dev, "%pOF set timing failed.\n",
 165                                 child);
 166                 else
 167                         have_child = 1;
 168         }
 169
 170         if (have_child)
 171                 ret = of_platform_default_populate(pdev->dev.of_node,
 172                                                    NULL, &pdev->dev);
 173         if (ret)
 174                 dev_err(&pdev->dev, "%pOF fail to create devices.\n",
 175                         pdev->dev.of_node);
 176         return ret;
 177 }
 178
 179 static int __init weim_probe(struct platform_device *pdev)
 180 {
 181         struct resource *res;
 182         struct clk *clk;
 183         void __iomem *base;
 184         int ret;
 185
 186         /* get the resource */
 187         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 188         base = devm_ioremap_resource(&pdev->dev, res);
 189         if (IS_ERR(base))
 190                 return PTR_ERR(base);
 191
 192         /* get the clock */
 193         clk = devm_clk_get(&pdev->dev, NULL);
 194         if (IS_ERR(clk))
 195                 return PTR_ERR(clk);
 196
 197         ret = clk_prepare_enable(clk);
 198         if (ret)
 199                 return ret;
 200
 201         /* parse the device node */
 202         ret = weim_parse_dt(pdev, base);
 203         if (ret)
 204                 clk_disable_unprepare(clk);
 205         else
 206                 dev_info(&pdev->dev, "Driver registered.\n");
 207
 208         return ret;
 209 }
 210
 211 static struct platform_driver weim_driver = {
 212         .driver = {
 213                 .name           = "imx-weim",
 214                 .of_match_table = weim_id_table,
 215         },
 216 };
 217 module_platform_driver_probe(weim_driver, weim_probe);
 218
 219 MODULE_AUTHOR("Freescale Semiconductor Inc.");
 220 MODULE_DESCRIPTION("i.MX EIM Controller Driver");
 221 MODULE_LICENSE("GPL");