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_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, "%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_default_populate(pdev->dev.of_node, 167 NULL, &pdev->dev); 168 if (ret) 169 dev_err(&pdev->dev, "%s fail to create devices.\n", 170 pdev->dev.of_node->full_name); 171 return ret; 172 } 173 174 static 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 } 205 206 static struct platform_driver weim_driver = { 207 .driver = { 208 .name = "imx-weim", 209 .of_match_table = weim_id_table, 210 }, 211 }; 212 module_platform_driver_probe(weim_driver, weim_probe); 213 214 MODULE_AUTHOR("Freescale Semiconductor Inc."); 215 MODULE_DESCRIPTION("i.MX EIM Controller Driver"); 216 MODULE_LICENSE("GPL"); 217