drivers/clk/clk-max77802.c

   1 /*
   2  * clk-max77802.c - Clock driver for Maxim 77802
   3  *
   4  * Copyright (C) 2014 Google, Inc
   5  *
   6  * Copyright (C) 2012 Samsung Electornics
   7  * Jonghwa Lee <jonghwa3.lee@samsung.com>
   8  *
   9  * This program is free software; you can redistribute  it and/or modify it
  10  * under  the terms of  the GNU General  Public License as published by the
  11  * Free Software Foundation;  either version 2 of the  License, or (at your
  12  * option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * This driver is based on clk-max77686.c
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/slab.h>
  24 #include <linux/err.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/mfd/max77686-private.h>
  27 #include <linux/clk-provider.h>
  28 #include <linux/mutex.h>
  29 #include <linux/clkdev.h>
  30
  31 #include <dt-bindings/clock/maxim,max77802.h>
  32 #include "clk-max-gen.h"
  33
  34 #define MAX77802_CLOCK_OPMODE_MASK      0x1
  35 #define MAX77802_CLOCK_LOW_JITTER_SHIFT 0x3
  36
  37 static struct clk_init_data max77802_clks_init[MAX77802_CLKS_NUM] = {
  38         [MAX77802_CLK_32K_AP] = {
  39                 .name = "32khz_ap",
  40                 .ops = &max_gen_clk_ops,
  41                 .flags = CLK_IS_ROOT,
  42         },
  43         [MAX77802_CLK_32K_CP] = {
  44                 .name = "32khz_cp",
  45                 .ops = &max_gen_clk_ops,
  46                 .flags = CLK_IS_ROOT,
  47         },
  48 };
  49
  50 static int max77802_clk_probe(struct platform_device *pdev)
  51 {
  52         struct max77686_dev *iodev = dev_get_drvdata(pdev->dev.parent);
  53         int ret;
  54
  55         ret = max_gen_clk_probe(pdev, iodev->regmap, MAX77802_REG_32KHZ,
  56                                 max77802_clks_init, MAX77802_CLKS_NUM);
  57
  58         if (ret) {
  59                 dev_err(&pdev->dev, "generic probe failed %d\n", ret);
  60                 return ret;
  61         }
  62
  63         /* Enable low-jitter mode on the 32khz clocks. */
  64         ret = regmap_update_bits(iodev->regmap, MAX77802_REG_32KHZ,
  65                                  1 << MAX77802_CLOCK_LOW_JITTER_SHIFT,
  66                                  1 << MAX77802_CLOCK_LOW_JITTER_SHIFT);
  67         if (ret < 0)
  68                 dev_err(&pdev->dev, "failed to enable low-jitter mode\n");
  69
  70         return ret;
  71 }
  72
  73 static int max77802_clk_remove(struct platform_device *pdev)
  74 {
  75         return max_gen_clk_remove(pdev, MAX77802_CLKS_NUM);
  76 }
  77
  78 static const struct platform_device_id max77802_clk_id[] = {
  79         { "max77802-clk", 0},
  80         { },
  81 };
  82 MODULE_DEVICE_TABLE(platform, max77802_clk_id);
  83
  84 static struct platform_driver max77802_clk_driver = {
  85         .driver = {
  86                 .name  = "max77802-clk",
  87         },
  88         .probe = max77802_clk_probe,
  89         .remove = max77802_clk_remove,
  90         .id_table = max77802_clk_id,
  91 };
  92
  93 module_platform_driver(max77802_clk_driver);
  94
  95 MODULE_DESCRIPTION("MAXIM 77802 Clock Driver");
  96 MODULE_AUTHOR("Javier Martinez Canillas <javier.martinez@collabora.co.uk>");
  97 MODULE_LICENSE("GPL");