Commit 73118e61 authored by Jonghwa Lee's avatar Jonghwa Lee Committed by Mike Turquette

clock: max77686: Add driver for Maxim 77686 32Khz crystal oscillator.

This patch supports max77686 mfd's clock driver using common clock frame work.
max77686 has 3 clock ouputs which all are generated from crystal oscillator and
SOC can enable/disable them via I2C bus. All clocks are fixed-rate clock sources
so that it doesn't supply interface for changing clock rate.
Driver uses regmap API to communicate with internal register.
Signed-off-by: default avatarJonghwa Lee <jonghwa3.lee@samsung.com>
Signed-off-by: default avatarMike Turquette <mturquette@linaro.org>
parent ebc96db7
......@@ -47,4 +47,10 @@ config COMMON_CLK_VERSATILE
Supports clocking on ARM Reference designs Integrator/AP,
Integrator/CP, RealView PB1176, EB, PB11MP and PBX.
config COMMON_CLK_MAX77686
tristate "Clock driver for Maxim 77686 MFD"
depends on MFD_MAX77686
---help---
This driver supports Maxim 77686 crystal oscillator clock.
endmenu
......@@ -19,3 +19,4 @@ obj-$(CONFIG_ARCH_U8500) += ux500/
# Chip specific
obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o
obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
/*
* clk-max77686.c - Clock driver for Maxim 77686
*
* Copyright (C) 2012 Samsung Electornics
* Jonghwa Lee <jonghwa3.lee@samsung.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/mfd/max77686.h>
#include <linux/mfd/max77686-private.h>
#include <linux/clk-provider.h>
#include <linux/mutex.h>
#include <linux/clkdev.h>
enum {
MAX77686_CLK_AP = 0,
MAX77686_CLK_CP,
MAX77686_CLK_PMIC,
MAX77686_CLKS_NUM,
};
struct max77686_clk {
struct max77686_dev *iodev;
u32 mask;
struct clk_hw hw;
struct clk_lookup *lookup;
};
static struct max77686_clk *get_max77686_clk(struct clk_hw *hw)
{
return container_of(hw, struct max77686_clk, hw);
}
static int max77686_clk_prepare(struct clk_hw *hw)
{
struct max77686_clk *max77686;
int ret;
max77686 = get_max77686_clk(hw);
if (!max77686)
return -ENOMEM;
ret = regmap_update_bits(max77686->iodev->regmap,
MAX77686_REG_32KHZ, max77686->mask, max77686->mask);
return ret;
}
static void max77686_clk_unprepare(struct clk_hw *hw)
{
struct max77686_clk *max77686;
max77686 = get_max77686_clk(hw);
if (!max77686)
return;
regmap_update_bits(max77686->iodev->regmap,
MAX77686_REG_32KHZ, max77686->mask, ~max77686->mask);
}
static int max77686_clk_is_enabled(struct clk_hw *hw)
{
struct max77686_clk *max77686;
int ret;
u32 val;
max77686 = get_max77686_clk(hw);
if (!max77686)
return -ENOMEM;
ret = regmap_read(max77686->iodev->regmap,
MAX77686_REG_32KHZ, &val);
if (ret < 0)
return -EINVAL;
return val & max77686->mask;
}
static struct clk_ops max77686_clk_ops = {
.prepare = max77686_clk_prepare,
.unprepare = max77686_clk_unprepare,
.is_enabled = max77686_clk_is_enabled,
};
static struct clk_init_data max77686_clks_init[MAX77686_CLKS_NUM] = {
[MAX77686_CLK_AP] = {
.name = "32khz_ap",
.ops = &max77686_clk_ops,
.flags = CLK_IS_ROOT,
},
[MAX77686_CLK_CP] = {
.name = "32khz_cp",
.ops = &max77686_clk_ops,
.flags = CLK_IS_ROOT,
},
[MAX77686_CLK_PMIC] = {
.name = "32khz_pmic",
.ops = &max77686_clk_ops,
.flags = CLK_IS_ROOT,
},
};
static int max77686_clk_register(struct device *dev,
struct max77686_clk *max77686)
{
struct clk *clk;
struct clk_hw *hw = &max77686->hw;
clk = clk_register(dev, hw);
if (IS_ERR(clk))
return -ENOMEM;
max77686->lookup = devm_kzalloc(dev, sizeof(struct clk_lookup),
GFP_KERNEL);
if (IS_ERR(max77686->lookup))
return -ENOMEM;
max77686->lookup->con_id = hw->init->name;
max77686->lookup->clk = clk;
clkdev_add(max77686->lookup);
return 0;
}
static __devinit int max77686_clk_probe(struct platform_device *pdev)
{
struct max77686_dev *iodev = dev_get_drvdata(pdev->dev.parent);
struct max77686_clk **max77686_clks;
int i, ret;
max77686_clks = devm_kzalloc(&pdev->dev, sizeof(struct max77686_clk *)
* MAX77686_CLKS_NUM, GFP_KERNEL);
if (IS_ERR(max77686_clks))
return -ENOMEM;
for (i = 0; i < MAX77686_CLKS_NUM; i++) {
max77686_clks[i] = devm_kzalloc(&pdev->dev,
sizeof(struct max77686_clk), GFP_KERNEL);
if (IS_ERR(max77686_clks[i]))
return -ENOMEM;
}
for (i = 0; i < MAX77686_CLKS_NUM; i++) {
max77686_clks[i]->iodev = iodev;
max77686_clks[i]->mask = 1 << i;
max77686_clks[i]->hw.init = &max77686_clks_init[i];
ret = max77686_clk_register(&pdev->dev, max77686_clks[i]);
if (ret) {
switch (i) {
case MAX77686_CLK_AP:
dev_err(&pdev->dev, "Fail to register CLK_AP\n");
goto err_clk_ap;
break;
case MAX77686_CLK_CP:
dev_err(&pdev->dev, "Fail to register CLK_CP\n");
goto err_clk_cp;
break;
case MAX77686_CLK_PMIC:
dev_err(&pdev->dev, "Fail to register CLK_PMIC\n");
goto err_clk_pmic;
}
}
}
platform_set_drvdata(pdev, max77686_clks);
goto out;
err_clk_pmic:
clkdev_drop(max77686_clks[MAX77686_CLK_CP]->lookup);
kfree(max77686_clks[MAX77686_CLK_CP]->hw.clk);
err_clk_cp:
clkdev_drop(max77686_clks[MAX77686_CLK_AP]->lookup);
kfree(max77686_clks[MAX77686_CLK_AP]->hw.clk);
err_clk_ap:
out:
return ret;
}
static int __devexit max77686_clk_remove(struct platform_device *pdev)
{
struct max77686_clk **max77686_clks = platform_get_drvdata(pdev);
int i;
for (i = 0; i < MAX77686_CLKS_NUM; i++) {
clkdev_drop(max77686_clks[i]->lookup);
kfree(max77686_clks[i]->hw.clk);
}
return 0;
}
static const struct platform_device_id max77686_clk_id[] = {
{ "max77686-clk", 0},
{ },
};
MODULE_DEVICE_TABLE(platform, max77686_clk_id);
static struct platform_driver max77686_clk_driver = {
.driver = {
.name = "max77686-clk",
.owner = THIS_MODULE,
},
.probe = max77686_clk_probe,
.remove = __devexit_p(max77686_clk_remove),
.id_table = max77686_clk_id,
};
static int __init max77686_clk_init(void)
{
return platform_driver_register(&max77686_clk_driver);
}
subsys_initcall(max77686_clk_init);
static void __init max77686_clk_cleanup(void)
{
platform_driver_unregister(&max77686_clk_driver);
}
module_exit(max77686_clk_cleanup);
MODULE_DESCRIPTION("MAXIM 77686 Clock Driver");
MODULE_AUTHOR("Jonghwa Lee <jonghwa3.lee@samsung.com>");
MODULE_LICENSE("GPL");
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