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_atomic(hregmap->regs + ATMEL_HLCDC_SR,
  54                                           status, !(status & ATMEL_HLCDC_SIP),
  55                                           1, 100);
  56         }
  57
  58         writel(val, hregmap->regs + reg);
  59
  60         return 0;
  61 }
  62
  63 static int regmap_atmel_hlcdc_reg_read(void *context, unsigned int reg,
  64                                        unsigned int *val)
  65 {
  66         struct atmel_hlcdc_regmap *hregmap = context;
  67
  68         *val = readl(hregmap->regs + reg);
  69
  70         return 0;
  71 }
  72
  73 static const struct regmap_config atmel_hlcdc_regmap_config = {
  74         .reg_bits = 32,
  75         .val_bits = 32,
  76         .reg_stride = 4,
  77         .max_register = ATMEL_HLCDC_REG_MAX,
  78         .reg_write = regmap_atmel_hlcdc_reg_write,
  79         .reg_read = regmap_atmel_hlcdc_reg_read,
  80         .fast_io = true,
  81 };
  82
  83 static int atmel_hlcdc_probe(struct platform_device *pdev)
  84 {
  85         struct atmel_hlcdc_regmap *hregmap;
  86         struct device *dev = &pdev->dev;
  87         struct atmel_hlcdc *hlcdc;
  88         struct resource *res;
  89
  90         hregmap = devm_kzalloc(dev, sizeof(*hregmap), GFP_KERNEL);
  91         if (!hregmap)
  92                 return -ENOMEM;
  93
  94         hlcdc = devm_kzalloc(dev, sizeof(*hlcdc), GFP_KERNEL);
  95         if (!hlcdc)
  96                 return -ENOMEM;
  97
  98         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  99         hregmap->regs = devm_ioremap_resource(dev, res);
 100         if (IS_ERR(hregmap->regs))
 101                 return PTR_ERR(hregmap->regs);
 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 mfd_add_devices(dev, -1, atmel_hlcdc_cells,
 133                                ARRAY_SIZE(atmel_hlcdc_cells),
 134                                NULL, 0, NULL);
 135 }
 136
 137 static int atmel_hlcdc_remove(struct platform_device *pdev)
 138 {
 139         mfd_remove_devices(&pdev->dev);
 140
 141         return 0;
 142 }
 143
 144 static const struct of_device_id atmel_hlcdc_match[] = {
 145         { .compatible = "atmel,at91sam9n12-hlcdc" },
 146         { .compatible = "atmel,at91sam9x5-hlcdc" },
 147         { .compatible = "atmel,sama5d2-hlcdc" },
 148         { .compatible = "atmel,sama5d3-hlcdc" },
 149         { .compatible = "atmel,sama5d4-hlcdc" },
 150         { /* sentinel */ },
 151 };
 152 MODULE_DEVICE_TABLE(of, atmel_hlcdc_match);
 153
 154 static struct platform_driver atmel_hlcdc_driver = {
 155         .probe = atmel_hlcdc_probe,
 156         .remove = atmel_hlcdc_remove,
 157         .driver = {
 158                 .name = "atmel-hlcdc",
 159                 .of_match_table = atmel_hlcdc_match,
 160         },
 161 };
 162 module_platform_driver(atmel_hlcdc_driver);
 163
 164 MODULE_ALIAS("platform:atmel-hlcdc");
 165 MODULE_AUTHOR("Boris Brezillon <boris.brezillon@free-electrons.com>");
 166 MODULE_DESCRIPTION("Atmel HLCDC driver");
 167 MODULE_LICENSE("GPL v2");