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/module.h>
  26 #include <linux/platform_device.h>
  27 #include <linux/mfd/max77686-private.h>
  28 #include <linux/clk-provider.h>
  29 #include <linux/mutex.h>
  30 #include <linux/clkdev.h>
  31
  32 #include <dt-bindings/clock/maxim,max77802.h>
  33 #include "clk-max-gen.h"
  34
  35 #define MAX77802_CLOCK_OPMODE_MASK      0x1
  36 #define MAX77802_CLOCK_LOW_JITTER_SHIFT 0x3
  37
  38 static struct clk_init_data max77802_clks_init[MAX77802_CLKS_NUM] = {
  39         [MAX77802_CLK_32K_AP] = {
  40                 .name = "32khz_ap",
  41                 .ops = &max_gen_clk_ops,
  42                 .flags = CLK_IS_ROOT,
  43         },
  44         [MAX77802_CLK_32K_CP] = {
  45                 .name = "32khz_cp",
  46                 .ops = &max_gen_clk_ops,
  47                 .flags = CLK_IS_ROOT,
  48         },
  49 };
  50
  51 static int max77802_clk_probe(struct platform_device *pdev)
  52 {
  53         struct max77686_dev *iodev = dev_get_drvdata(pdev->dev.parent);
  54         int ret;
  55
  56         ret = max_gen_clk_probe(pdev, iodev->regmap, MAX77802_REG_32KHZ,
  57                                 max77802_clks_init, MAX77802_CLKS_NUM);
  58
  59         if (ret) {
  60                 dev_err(&pdev->dev, "generic probe failed %d\n", ret);
  61                 return ret;
  62         }
  63
  64         /* Enable low-jitter mode on the 32khz clocks. */
  65         ret = regmap_update_bits(iodev->regmap, MAX77802_REG_32KHZ,
  66                                  1 << MAX77802_CLOCK_LOW_JITTER_SHIFT,
  67                                  1 << MAX77802_CLOCK_LOW_JITTER_SHIFT);
  68         if (ret < 0)
  69                 dev_err(&pdev->dev, "failed to enable low-jitter mode\n");
  70
  71         return ret;
  72 }
  73
  74 static int max77802_clk_remove(struct platform_device *pdev)
  75 {
  76         return max_gen_clk_remove(pdev, MAX77802_CLKS_NUM);
  77 }
  78
  79 static const struct platform_device_id max77802_clk_id[] = {
  80         { "max77802-clk", 0},
  81         { },
  82 };
  83 MODULE_DEVICE_TABLE(platform, max77802_clk_id);
  84
  85 static struct platform_driver max77802_clk_driver = {
  86         .driver = {
  87                 .name  = "max77802-clk",
  88         },
  89         .probe = max77802_clk_probe,
  90         .remove = max77802_clk_remove,
  91         .id_table = max77802_clk_id,
  92 };
  93
  94 module_platform_driver(max77802_clk_driver);
  95
  96 MODULE_DESCRIPTION("MAXIM 77802 Clock Driver");
  97 MODULE_AUTHOR("Javier Martinez Canillas <javier.martinez@collabora.co.uk>");
  98 MODULE_LICENSE("GPL");