linux/drivers/clk/clk-palmas.c

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/*
* Clock driver for Palmas device.
*
* Copyright (c) 2013, NVIDIA Corporation.
* Copyright (c) 2013-2014 Texas Instruments, Inc.
*
* Author: Laxman Dewangan <ldewangan@nvidia.com>
* Peter Ujfalusi <peter.ujfalusi@ti.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 version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
* whether express or implied; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/mfd/palmas.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#define PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE1 1
#define PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE2 2
#define PALMAS_CLOCK_DT_EXT_CONTROL_NSLEEP 3
struct palmas_clk32k_desc {
const char *clk_name;
unsigned int control_reg;
unsigned int enable_mask;
unsigned int sleep_mask;
unsigned int sleep_reqstr_id;
int delay;
};
struct palmas_clock_info {
struct device *dev;
struct clk *clk;
struct clk_hw hw;
struct palmas *palmas;
struct palmas_clk32k_desc *clk_desc;
int ext_control_pin;
};
static inline struct palmas_clock_info *to_palmas_clks_info(struct clk_hw *hw)
{
return container_of(hw, struct palmas_clock_info, hw);
}
static unsigned long palmas_clks_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
return 32768;
}
static int palmas_clks_prepare(struct clk_hw *hw)
{
struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
int ret;
ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
cinfo->clk_desc->control_reg,
cinfo->clk_desc->enable_mask,
cinfo->clk_desc->enable_mask);
if (ret < 0)
dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
cinfo->clk_desc->control_reg, ret);
else if (cinfo->clk_desc->delay)
udelay(cinfo->clk_desc->delay);
return ret;
}
static void palmas_clks_unprepare(struct clk_hw *hw)
{
struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
int ret;
/*
* Clock can be disabled through external pin if it is externally
* controlled.
*/
if (cinfo->ext_control_pin)
return;
ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
cinfo->clk_desc->control_reg,
cinfo->clk_desc->enable_mask, 0);
if (ret < 0)
dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
cinfo->clk_desc->control_reg, ret);
}
static int palmas_clks_is_prepared(struct clk_hw *hw)
{
struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
int ret;
u32 val;
if (cinfo->ext_control_pin)
return 1;
ret = palmas_read(cinfo->palmas, PALMAS_RESOURCE_BASE,
cinfo->clk_desc->control_reg, &val);
if (ret < 0) {
dev_err(cinfo->dev, "Reg 0x%02x read failed, %d\n",
cinfo->clk_desc->control_reg, ret);
return ret;
}
return !!(val & cinfo->clk_desc->enable_mask);
}
static struct clk_ops palmas_clks_ops = {
.prepare = palmas_clks_prepare,
.unprepare = palmas_clks_unprepare,
.is_prepared = palmas_clks_is_prepared,
.recalc_rate = palmas_clks_recalc_rate,
};
struct palmas_clks_of_match_data {
struct clk_init_data init;
struct palmas_clk32k_desc desc;
};
static struct palmas_clks_of_match_data palmas_of_clk32kg = {
.init = {
.name = "clk32kg",
.ops = &palmas_clks_ops,
.flags = CLK_IS_ROOT | CLK_IGNORE_UNUSED,
},
.desc = {
.clk_name = "clk32kg",
.control_reg = PALMAS_CLK32KG_CTRL,
.enable_mask = PALMAS_CLK32KG_CTRL_MODE_ACTIVE,
.sleep_mask = PALMAS_CLK32KG_CTRL_MODE_SLEEP,
.sleep_reqstr_id = PALMAS_EXTERNAL_REQSTR_ID_CLK32KG,
.delay = 200,
},
};
static struct palmas_clks_of_match_data palmas_of_clk32kgaudio = {
.init = {
.name = "clk32kgaudio",
.ops = &palmas_clks_ops,
.flags = CLK_IS_ROOT | CLK_IGNORE_UNUSED,
},
.desc = {
.clk_name = "clk32kgaudio",
.control_reg = PALMAS_CLK32KGAUDIO_CTRL,
.enable_mask = PALMAS_CLK32KG_CTRL_MODE_ACTIVE,
.sleep_mask = PALMAS_CLK32KG_CTRL_MODE_SLEEP,
.sleep_reqstr_id = PALMAS_EXTERNAL_REQSTR_ID_CLK32KGAUDIO,
.delay = 200,
},
};
static struct of_device_id palmas_clks_of_match[] = {
{
.compatible = "ti,palmas-clk32kg",
.data = &palmas_of_clk32kg,
},
{
.compatible = "ti,palmas-clk32kgaudio",
.data = &palmas_of_clk32kgaudio,
},
{ },
};
MODULE_DEVICE_TABLE(of, palmas_clks_of_match);
static void palmas_clks_get_clk_data(struct platform_device *pdev,
struct palmas_clock_info *cinfo)
{
struct device_node *node = pdev->dev.of_node;
unsigned int prop;
int ret;
ret = of_property_read_u32(node, "ti,external-sleep-control",
&prop);
if (ret)
return;
switch (prop) {
case PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE1:
prop = PALMAS_EXT_CONTROL_ENABLE1;
break;
case PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE2:
prop = PALMAS_EXT_CONTROL_ENABLE2;
break;
case PALMAS_CLOCK_DT_EXT_CONTROL_NSLEEP:
prop = PALMAS_EXT_CONTROL_NSLEEP;
break;
default:
dev_warn(&pdev->dev, "%s: Invalid ext control option: %u\n",
node->name, prop);
prop = 0;
break;
}
cinfo->ext_control_pin = prop;
}
static int palmas_clks_init_configure(struct palmas_clock_info *cinfo)
{
int ret;
ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
cinfo->clk_desc->control_reg,
cinfo->clk_desc->sleep_mask, 0);
if (ret < 0) {
dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
cinfo->clk_desc->control_reg, ret);
return ret;
}
if (cinfo->ext_control_pin) {
ret = clk_prepare(cinfo->clk);
if (ret < 0) {
dev_err(cinfo->dev, "Clock prep failed, %d\n", ret);
return ret;
}
ret = palmas_ext_control_req_config(cinfo->palmas,
cinfo->clk_desc->sleep_reqstr_id,
cinfo->ext_control_pin, true);
if (ret < 0) {
dev_err(cinfo->dev, "Ext config for %s failed, %d\n",
cinfo->clk_desc->clk_name, ret);
return ret;
}
}
return ret;
}
static int palmas_clks_probe(struct platform_device *pdev)
{
struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
struct device_node *node = pdev->dev.of_node;
struct palmas_clks_of_match_data *match_data;
const struct of_device_id *match;
struct palmas_clock_info *cinfo;
struct clk *clk;
int ret;
match = of_match_device(palmas_clks_of_match, &pdev->dev);
match_data = (struct palmas_clks_of_match_data *)match->data;
cinfo = devm_kzalloc(&pdev->dev, sizeof(*cinfo), GFP_KERNEL);
if (!cinfo)
return -ENOMEM;
palmas_clks_get_clk_data(pdev, cinfo);
platform_set_drvdata(pdev, cinfo);
cinfo->dev = &pdev->dev;
cinfo->palmas = palmas;
cinfo->clk_desc = &match_data->desc;
cinfo->hw.init = &match_data->init;
clk = devm_clk_register(&pdev->dev, &cinfo->hw);
if (IS_ERR(clk)) {
ret = PTR_ERR(clk);
dev_err(&pdev->dev, "Fail to register clock %s, %d\n",
match_data->desc.clk_name, ret);
return ret;
}
cinfo->clk = clk;
ret = palmas_clks_init_configure(cinfo);
if (ret < 0) {
dev_err(&pdev->dev, "Clock config failed, %d\n", ret);
return ret;
}
ret = of_clk_add_provider(node, of_clk_src_simple_get, cinfo->clk);
if (ret < 0)
dev_err(&pdev->dev, "Fail to add clock driver, %d\n", ret);
return ret;
}
static int palmas_clks_remove(struct platform_device *pdev)
{
of_clk_del_provider(pdev->dev.of_node);
return 0;
}
static struct platform_driver palmas_clks_driver = {
.driver = {
.name = "palmas-clk",
.of_match_table = palmas_clks_of_match,
},
.probe = palmas_clks_probe,
.remove = palmas_clks_remove,
};
module_platform_driver(palmas_clks_driver);
MODULE_DESCRIPTION("Clock driver for Palmas Series Devices");
MODULE_ALIAS("platform:palmas-clk");
MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
MODULE_LICENSE("GPL v2");