1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * i.MX IIM driver 4 * 5 * Copyright (c) 2017 Pengutronix, Michael Grzeschik <m.grzeschik@pengutronix.de> 6 * 7 * Based on the barebox iim driver, 8 * Copyright (c) 2010 Baruch Siach <baruch@tkos.co.il>, 9 * Orex Computed Radiography 10 */ 11 12 #include <linux/device.h> 13 #include <linux/io.h> 14 #include <linux/module.h> 15 #include <linux/nvmem-provider.h> 16 #include <linux/of.h> 17 #include <linux/of_device.h> 18 #include <linux/platform_device.h> 19 #include <linux/slab.h> 20 #include <linux/clk.h> 21 22 #define IIM_BANK_BASE(n) (0x800 + 0x400 * (n)) 23 24 struct imx_iim_drvdata { 25 unsigned int nregs; 26 }; 27 28 struct iim_priv { 29 void __iomem *base; 30 struct clk *clk; 31 }; 32 33 static int imx_iim_read(void *context, unsigned int offset, 34 void *buf, size_t bytes) 35 { 36 struct iim_priv *iim = context; 37 int i, ret; 38 u8 *buf8 = buf; 39 40 ret = clk_prepare_enable(iim->clk); 41 if (ret) 42 return ret; 43 44 for (i = offset; i < offset + bytes; i++) { 45 int bank = i >> 5; 46 int reg = i & 0x1f; 47 48 *buf8++ = readl(iim->base + IIM_BANK_BASE(bank) + reg * 4); 49 } 50 51 clk_disable_unprepare(iim->clk); 52 53 return 0; 54 } 55 56 static struct imx_iim_drvdata imx27_drvdata = { 57 .nregs = 2 * 32, 58 }; 59 60 static struct imx_iim_drvdata imx25_imx31_imx35_drvdata = { 61 .nregs = 3 * 32, 62 }; 63 64 static struct imx_iim_drvdata imx51_drvdata = { 65 .nregs = 4 * 32, 66 }; 67 68 static struct imx_iim_drvdata imx53_drvdata = { 69 .nregs = 4 * 32 + 16, 70 }; 71 72 static const struct of_device_id imx_iim_dt_ids[] = { 73 { 74 .compatible = "fsl,imx25-iim", 75 .data = &imx25_imx31_imx35_drvdata, 76 }, { 77 .compatible = "fsl,imx27-iim", 78 .data = &imx27_drvdata, 79 }, { 80 .compatible = "fsl,imx31-iim", 81 .data = &imx25_imx31_imx35_drvdata, 82 }, { 83 .compatible = "fsl,imx35-iim", 84 .data = &imx25_imx31_imx35_drvdata, 85 }, { 86 .compatible = "fsl,imx51-iim", 87 .data = &imx51_drvdata, 88 }, { 89 .compatible = "fsl,imx53-iim", 90 .data = &imx53_drvdata, 91 }, { 92 /* sentinel */ 93 }, 94 }; 95 MODULE_DEVICE_TABLE(of, imx_iim_dt_ids); 96 97 static int imx_iim_probe(struct platform_device *pdev) 98 { 99 const struct of_device_id *of_id; 100 struct device *dev = &pdev->dev; 101 struct iim_priv *iim; 102 struct nvmem_device *nvmem; 103 struct nvmem_config cfg = {}; 104 const struct imx_iim_drvdata *drvdata = NULL; 105 106 iim = devm_kzalloc(dev, sizeof(*iim), GFP_KERNEL); 107 if (!iim) 108 return -ENOMEM; 109 110 iim->base = devm_platform_ioremap_resource(pdev, 0); 111 if (IS_ERR(iim->base)) 112 return PTR_ERR(iim->base); 113 114 of_id = of_match_device(imx_iim_dt_ids, dev); 115 if (!of_id) 116 return -ENODEV; 117 118 drvdata = of_id->data; 119 120 iim->clk = devm_clk_get(dev, NULL); 121 if (IS_ERR(iim->clk)) 122 return PTR_ERR(iim->clk); 123 124 cfg.name = "imx-iim", 125 cfg.read_only = true, 126 cfg.word_size = 1, 127 cfg.stride = 1, 128 cfg.reg_read = imx_iim_read, 129 cfg.dev = dev; 130 cfg.size = drvdata->nregs; 131 cfg.priv = iim; 132 133 nvmem = devm_nvmem_register(dev, &cfg); 134 135 return PTR_ERR_OR_ZERO(nvmem); 136 } 137 138 static struct platform_driver imx_iim_driver = { 139 .probe = imx_iim_probe, 140 .driver = { 141 .name = "imx-iim", 142 .of_match_table = imx_iim_dt_ids, 143 }, 144 }; 145 module_platform_driver(imx_iim_driver); 146 147 MODULE_AUTHOR("Michael Grzeschik <m.grzeschik@pengutronix.de>"); 148 MODULE_DESCRIPTION("i.MX IIM driver"); 149 MODULE_LICENSE("GPL v2"); 150