tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
38static 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
51static 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
74static int max77802_clk_remove(struct platform_device *pdev)
75{
76 return max_gen_clk_remove(pdev, MAX77802_CLKS_NUM);
77}
78
79static const struct platform_device_id max77802_clk_id[] = {
80 { "max77802-clk", 0},
81 { },
82};
83MODULE_DEVICE_TABLE(platform, max77802_clk_id);
84
85static 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
94module_platform_driver(max77802_clk_driver);
95
96MODULE_DESCRIPTION("MAXIM 77802 Clock Driver");
97MODULE_AUTHOR("Javier Martinez Canillas <javier@osg.samsung.com");
98MODULE_LICENSE("GPL");