drivers/mfd/atmel-hlcdc.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2014 Free Electrons
   4  * Copyright (C) 2014 Atmel
   5  *
   6  * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
   7  */
   8
   9 #include <linux/clk.h>
  10 #include <linux/iopoll.h>
  11 #include <linux/mfd/atmel-hlcdc.h>
  12 #include <linux/mfd/core.h>
  13 #include <linux/module.h>
  14 #include <linux/mod_devicetable.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/regmap.h>
  17
  18 #define ATMEL_HLCDC_REG_MAX             (0x4000 - 0x4)
  19
  20 struct atmel_hlcdc_regmap {
  21         void __iomem *regs;
  22         struct device *dev;
  23 };
  24
  25 static const struct mfd_cell atmel_hlcdc_cells[] = {
  26         {
  27                 .name = "atmel-hlcdc-pwm",
  28                 .of_compatible = "atmel,hlcdc-pwm",
  29         },
  30         {
  31                 .name = "atmel-hlcdc-dc",
  32                 .of_compatible = "atmel,hlcdc-display-controller",
  33         },
  34 };
  35
  36 static int regmap_atmel_hlcdc_reg_write(void *context, unsigned int reg,
  37                                         unsigned int val)
  38 {
  39         struct atmel_hlcdc_regmap *hregmap = context;
  40
  41         if (reg <= ATMEL_HLCDC_DIS) {
  42                 u32 status;
  43                 int ret;
  44
  45                 ret = readl_poll_timeout_atomic(hregmap->regs + ATMEL_HLCDC_SR,
  46                                                 status,
  47                                                 !(status & ATMEL_HLCDC_SIP),
  48                                                 1, 100);
  49                 if (ret) {
  50                         dev_err(hregmap->dev,
  51                                 "Timeout! Clock domain synchronization is in progress!\n");
  52                         return ret;
  53                 }
  54         }
  55
  56         writel(val, hregmap->regs + reg);
  57
  58         return 0;
  59 }
  60
  61 static int regmap_atmel_hlcdc_reg_read(void *context, unsigned int reg,
  62                                        unsigned int *val)
  63 {
  64         struct atmel_hlcdc_regmap *hregmap = context;
  65
  66         *val = readl(hregmap->regs + reg);
  67
  68         return 0;
  69 }
  70
  71 static const struct regmap_config atmel_hlcdc_regmap_config = {
  72         .reg_bits = 32,
  73         .val_bits = 32,
  74         .reg_stride = 4,
  75         .max_register = ATMEL_HLCDC_REG_MAX,
  76         .reg_write = regmap_atmel_hlcdc_reg_write,
  77         .reg_read = regmap_atmel_hlcdc_reg_read,
  78         .fast_io = true,
  79 };
  80
  81 static int atmel_hlcdc_probe(struct platform_device *pdev)
  82 {
  83         struct atmel_hlcdc_regmap *hregmap;
  84         struct device *dev = &pdev->dev;
  85         struct atmel_hlcdc *hlcdc;
  86         struct resource *res;
  87
  88         hregmap = devm_kzalloc(dev, sizeof(*hregmap), GFP_KERNEL);
  89         if (!hregmap)
  90                 return -ENOMEM;
  91
  92         hlcdc = devm_kzalloc(dev, sizeof(*hlcdc), GFP_KERNEL);
  93         if (!hlcdc)
  94                 return -ENOMEM;
  95
  96         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  97         hregmap->regs = devm_ioremap_resource(dev, res);
  98         if (IS_ERR(hregmap->regs))
  99                 return PTR_ERR(hregmap->regs);
 100
 101         hregmap->dev = &pdev->dev;
 102
 103         hlcdc->irq = platform_get_irq(pdev, 0);
 104         if (hlcdc->irq < 0)
 105                 return hlcdc->irq;
 106
 107         hlcdc->periph_clk = devm_clk_get(dev, "periph_clk");
 108         if (IS_ERR(hlcdc->periph_clk)) {
 109                 dev_err(dev, "failed to get peripheral clock\n");
 110                 return PTR_ERR(hlcdc->periph_clk);
 111         }
 112
 113         hlcdc->sys_clk = devm_clk_get(dev, "sys_clk");
 114         if (IS_ERR(hlcdc->sys_clk)) {
 115                 dev_err(dev, "failed to get system clock\n");
 116                 return PTR_ERR(hlcdc->sys_clk);
 117         }
 118
 119         hlcdc->slow_clk = devm_clk_get(dev, "slow_clk");
 120         if (IS_ERR(hlcdc->slow_clk)) {
 121                 dev_err(dev, "failed to get slow clock\n");
 122                 return PTR_ERR(hlcdc->slow_clk);
 123         }
 124
 125         hlcdc->regmap = devm_regmap_init(dev, NULL, hregmap,
 126                                          &atmel_hlcdc_regmap_config);
 127         if (IS_ERR(hlcdc->regmap))
 128                 return PTR_ERR(hlcdc->regmap);
 129
 130         dev_set_drvdata(dev, hlcdc);
 131
 132         return devm_mfd_add_devices(dev, -1, atmel_hlcdc_cells,
 133                                     ARRAY_SIZE(atmel_hlcdc_cells),
 134                                     NULL, 0, NULL);
 135 }
 136
 137 static const struct of_device_id atmel_hlcdc_match[] = {
 138         { .compatible = "atmel,at91sam9n12-hlcdc" },
 139         { .compatible = "atmel,at91sam9x5-hlcdc" },
 140         { .compatible = "atmel,sama5d2-hlcdc" },
 141         { .compatible = "atmel,sama5d3-hlcdc" },
 142         { .compatible = "atmel,sama5d4-hlcdc" },
 143         { .compatible = "microchip,sam9x60-hlcdc" },
 144         { /* sentinel */ },
 145 };
 146 MODULE_DEVICE_TABLE(of, atmel_hlcdc_match);
 147
 148 static struct platform_driver atmel_hlcdc_driver = {
 149         .probe = atmel_hlcdc_probe,
 150         .driver = {
 151                 .name = "atmel-hlcdc",
 152                 .of_match_table = atmel_hlcdc_match,
 153         },
 154 };
 155 module_platform_driver(atmel_hlcdc_driver);
 156
 157 MODULE_ALIAS("platform:atmel-hlcdc");
 158 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
 159 MODULE_DESCRIPTION("Atmel HLCDC driver");
 160 MODULE_LICENSE("GPL v2");