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