drivers/mfd/atmel-hlcdc.c

   1 /*
   2  * Copyright (C) 2014 Free Electrons
   3  * Copyright (C) 2014 Atmel
   4  *
   5  * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along with
  17  * this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <linux/clk.h>
  21 #include <linux/iopoll.h>
  22 #include <linux/mfd/atmel-hlcdc.h>
  23 #include <linux/mfd/core.h>
  24 #include <linux/module.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/regmap.h>
  27
  28 #define ATMEL_HLCDC_REG_MAX             (0x4000 - 0x4)
  29
  30 struct atmel_hlcdc_regmap {
  31         void __iomem *regs;
  32 };
  33
  34 static const struct mfd_cell atmel_hlcdc_cells[] = {
  35         {
  36                 .name = "atmel-hlcdc-pwm",
  37                 .of_compatible = "atmel,hlcdc-pwm",
  38         },
  39         {
  40                 .name = "atmel-hlcdc-dc",
  41                 .of_compatible = "atmel,hlcdc-display-controller",
  42         },
  43 };
  44
  45 static int regmap_atmel_hlcdc_reg_write(void *context, unsigned int reg,
  46                                         unsigned int val)
  47 {
  48         struct atmel_hlcdc_regmap *hregmap = context;
  49
  50         if (reg <= ATMEL_HLCDC_DIS) {
  51                 u32 status;
  52
  53                 readl_poll_timeout(hregmap->regs + ATMEL_HLCDC_SR, status,
  54                                    !(status & ATMEL_HLCDC_SIP), 1, 100);
  55         }
  56
  57         writel(val, hregmap->regs + reg);
  58
  59         return 0;
  60 }
  61
  62 static int regmap_atmel_hlcdc_reg_read(void *context, unsigned int reg,
  63                                        unsigned int *val)
  64 {
  65         struct atmel_hlcdc_regmap *hregmap = context;
  66
  67         *val = readl(hregmap->regs + reg);
  68
  69         return 0;
  70 }
  71
  72 static const struct regmap_config atmel_hlcdc_regmap_config = {
  73         .reg_bits = 32,
  74         .val_bits = 32,
  75         .reg_stride = 4,
  76         .max_register = ATMEL_HLCDC_REG_MAX,
  77         .reg_write = regmap_atmel_hlcdc_reg_write,
  78         .reg_read = regmap_atmel_hlcdc_reg_read,
  79         .fast_io = true,
  80 };
  81
  82 static int atmel_hlcdc_probe(struct platform_device *pdev)
  83 {
  84         struct atmel_hlcdc_regmap *hregmap;
  85         struct device *dev = &pdev->dev;
  86         struct atmel_hlcdc *hlcdc;
  87         struct resource *res;
  88
  89         hregmap = devm_kzalloc(dev, sizeof(*hregmap), GFP_KERNEL);
  90         if (!hregmap)
  91                 return -ENOMEM;
  92
  93         hlcdc = devm_kzalloc(dev, sizeof(*hlcdc), GFP_KERNEL);
  94         if (!hlcdc)
  95                 return -ENOMEM;
  96
  97         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  98         hregmap->regs = devm_ioremap_resource(dev, res);
  99         if (IS_ERR(hregmap->regs))
 100                 return PTR_ERR(hregmap->regs);
 101
 102         hlcdc->irq = platform_get_irq(pdev, 0);
 103         if (hlcdc->irq < 0)
 104                 return hlcdc->irq;
 105
 106         hlcdc->periph_clk = devm_clk_get(dev, "periph_clk");
 107         if (IS_ERR(hlcdc->periph_clk)) {
 108                 dev_err(dev, "failed to get peripheral clock\n");
 109                 return PTR_ERR(hlcdc->periph_clk);
 110         }
 111
 112         hlcdc->sys_clk = devm_clk_get(dev, "sys_clk");
 113         if (IS_ERR(hlcdc->sys_clk)) {
 114                 dev_err(dev, "failed to get system clock\n");
 115                 return PTR_ERR(hlcdc->sys_clk);
 116         }
 117
 118         hlcdc->slow_clk = devm_clk_get(dev, "slow_clk");
 119         if (IS_ERR(hlcdc->slow_clk)) {
 120                 dev_err(dev, "failed to get slow clock\n");
 121                 return PTR_ERR(hlcdc->slow_clk);
 122         }
 123
 124         hlcdc->regmap = devm_regmap_init(dev, NULL, hregmap,
 125                                          &atmel_hlcdc_regmap_config);
 126         if (IS_ERR(hlcdc->regmap))
 127                 return PTR_ERR(hlcdc->regmap);
 128
 129         dev_set_drvdata(dev, hlcdc);
 130
 131         return mfd_add_devices(dev, -1, atmel_hlcdc_cells,
 132                                ARRAY_SIZE(atmel_hlcdc_cells),
 133                                NULL, 0, NULL);
 134 }
 135
 136 static int atmel_hlcdc_remove(struct platform_device *pdev)
 137 {
 138         mfd_remove_devices(&pdev->dev);
 139
 140         return 0;
 141 }
 142
 143 static const struct of_device_id atmel_hlcdc_match[] = {
 144         { .compatible = "atmel,at91sam9n12-hlcdc" },
 145         { .compatible = "atmel,at91sam9x5-hlcdc" },
 146         { .compatible = "atmel,sama5d2-hlcdc" },
 147         { .compatible = "atmel,sama5d3-hlcdc" },
 148         { .compatible = "atmel,sama5d4-hlcdc" },
 149         { /* sentinel */ },
 150 };
 151 MODULE_DEVICE_TABLE(of, atmel_hlcdc_match);
 152
 153 static struct platform_driver atmel_hlcdc_driver = {
 154         .probe = atmel_hlcdc_probe,
 155         .remove = atmel_hlcdc_remove,
 156         .driver = {
 157                 .name = "atmel-hlcdc",
 158                 .of_match_table = atmel_hlcdc_match,
 159         },
 160 };
 161 module_platform_driver(atmel_hlcdc_driver);
 162
 163 MODULE_ALIAS("platform:atmel-hlcdc");
 164 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
 165 MODULE_DESCRIPTION("Atmel HLCDC driver");
 166 MODULE_LICENSE("GPL v2");