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"); 222