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/mod_devicetable.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/regmap.h>
  28
  29 #define ATMEL_HLCDC_REG_MAX             (0x4000 - 0x4)
  30
  31 struct atmel_hlcdc_regmap {
  32         void __iomem *regs;
  33 };
  34
  35 static const struct mfd_cell atmel_hlcdc_cells[] = {
  36         {
  37                 .name = "atmel-hlcdc-pwm",
  38                 .of_compatible = "atmel,hlcdc-pwm",
  39         },
  40         {
  41                 .name = "atmel-hlcdc-dc",
  42                 .of_compatible = "atmel,hlcdc-display-controller",
  43         },
  44 };
  45
  46 static int regmap_atmel_hlcdc_reg_write(void *context, unsigned int reg,
  47                                         unsigned int val)
  48 {
  49         struct atmel_hlcdc_regmap *hregmap = context;
  50
  51         if (reg <= ATMEL_HLCDC_DIS) {
  52                 u32 status;
  53
  54                 readl_poll_timeout_atomic(hregmap->regs + ATMEL_HLCDC_SR,
  55                                           status, !(status & ATMEL_HLCDC_SIP),
  56                                           1, 100);
  57         }
  58
  59         writel(val, hregmap->regs + reg);
  60
  61         return 0;
  62 }
  63
  64 static int regmap_atmel_hlcdc_reg_read(void *context, unsigned int reg,
  65                                        unsigned int *val)
  66 {
  67         struct atmel_hlcdc_regmap *hregmap = context;
  68
  69         *val = readl(hregmap->regs + reg);
  70
  71         return 0;
  72 }
  73
  74 static const struct regmap_config atmel_hlcdc_regmap_config = {
  75         .reg_bits = 32,
  76         .val_bits = 32,
  77         .reg_stride = 4,
  78         .max_register = ATMEL_HLCDC_REG_MAX,
  79         .reg_write = regmap_atmel_hlcdc_reg_write,
  80         .reg_read = regmap_atmel_hlcdc_reg_read,
  81         .fast_io = true,
  82 };
  83
  84 static int atmel_hlcdc_probe(struct platform_device *pdev)
  85 {
  86         struct atmel_hlcdc_regmap *hregmap;
  87         struct device *dev = &pdev->dev;
  88         struct atmel_hlcdc *hlcdc;
  89         struct resource *res;
  90
  91         hregmap = devm_kzalloc(dev, sizeof(*hregmap), GFP_KERNEL);
  92         if (!hregmap)
  93                 return -ENOMEM;
  94
  95         hlcdc = devm_kzalloc(dev, sizeof(*hlcdc), GFP_KERNEL);
  96         if (!hlcdc)
  97                 return -ENOMEM;
  98
  99         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 100         hregmap->regs = devm_ioremap_resource(dev, res);
 101         if (IS_ERR(hregmap->regs))
 102                 return PTR_ERR(hregmap->regs);
 103
 104         hlcdc->irq = platform_get_irq(pdev, 0);
 105         if (hlcdc->irq < 0)
 106                 return hlcdc->irq;
 107
 108         hlcdc->periph_clk = devm_clk_get(dev, "periph_clk");
 109         if (IS_ERR(hlcdc->periph_clk)) {
 110                 dev_err(dev, "failed to get peripheral clock\n");
 111                 return PTR_ERR(hlcdc->periph_clk);
 112         }
 113
 114         hlcdc->sys_clk = devm_clk_get(dev, "sys_clk");
 115         if (IS_ERR(hlcdc->sys_clk)) {
 116                 dev_err(dev, "failed to get system clock\n");
 117                 return PTR_ERR(hlcdc->sys_clk);
 118         }
 119
 120         hlcdc->slow_clk = devm_clk_get(dev, "slow_clk");
 121         if (IS_ERR(hlcdc->slow_clk)) {
 122                 dev_err(dev, "failed to get slow clock\n");
 123                 return PTR_ERR(hlcdc->slow_clk);
 124         }
 125
 126         hlcdc->regmap = devm_regmap_init(dev, NULL, hregmap,
 127                                          &atmel_hlcdc_regmap_config);
 128         if (IS_ERR(hlcdc->regmap))
 129                 return PTR_ERR(hlcdc->regmap);
 130
 131         dev_set_drvdata(dev, hlcdc);
 132
 133         return devm_mfd_add_devices(dev, -1, atmel_hlcdc_cells,
 134                                     ARRAY_SIZE(atmel_hlcdc_cells),
 135                                     NULL, 0, NULL);
 136 }
 137
 138 static const struct of_device_id atmel_hlcdc_match[] = {
 139         { .compatible = "atmel,at91sam9n12-hlcdc" },
 140         { .compatible = "atmel,at91sam9x5-hlcdc" },
 141         { .compatible = "atmel,sama5d2-hlcdc" },
 142         { .compatible = "atmel,sama5d3-hlcdc" },
 143         { .compatible = "atmel,sama5d4-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");