CLK: clk-twl6040: Initial clock driver for OMAP4+ McPDM fclk clock

On OMAP4+ platforms the functional clock for the McPDM IP is suplied by
the twl6040 codec (bit clock on the PDM bus).
This common clock driver for twl6040 will register the mcpdm_fclk clock to
be used by the McPDM driver to make sure that the needed clocks are
available when needed.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
This commit is contained in:
Peter Ujfalusi 2012-09-14 17:30:27 +03:00 committed by Mike Turquette
parent 2968f85185
commit f9f8c0438d
3 changed files with 135 additions and 0 deletions

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@ -53,4 +53,12 @@ config COMMON_CLK_MAX77686
---help---
This driver supports Maxim 77686 crystal oscillator clock.
config CLK_TWL6040
tristate "External McPDM functional clock from twl6040"
depends on TWL6040_CORE
---help---
Enable the external functional clock support on OMAP4+ platforms for
McPDM. McPDM module is using the external bit clock on the McPDM bus
as functional clock.
endmenu

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@ -23,3 +23,4 @@ obj-$(CONFIG_ARCH_VT8500) += clk-vt8500.o
# Chip specific
obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o
obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
obj-$(CONFIG_CLK_TWL6040) += clk-twl6040.o

126
drivers/clk/clk-twl6040.c Normal file
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@ -0,0 +1,126 @@
/*
* TWL6040 clock module driver for OMAP4 McPDM functional clock
*
* Copyright (C) 2012 Texas Instruments Inc.
* 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
* version 2 as published by the Free Software Foundation.
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/mfd/twl6040.h>
#include <linux/clk-provider.h>
struct twl6040_clk {
struct twl6040 *twl6040;
struct device *dev;
struct clk_hw mcpdm_fclk;
struct clk *clk;
int enabled;
};
static int twl6040_bitclk_is_enabled(struct clk_hw *hw)
{
struct twl6040_clk *twl6040_clk = container_of(hw, struct twl6040_clk,
mcpdm_fclk);
return twl6040_clk->enabled;
}
static int twl6040_bitclk_prepare(struct clk_hw *hw)
{
struct twl6040_clk *twl6040_clk = container_of(hw, struct twl6040_clk,
mcpdm_fclk);
int ret;
ret = twl6040_power(twl6040_clk->twl6040, 1);
if (!ret)
twl6040_clk->enabled = 1;
return ret;
}
static void twl6040_bitclk_unprepare(struct clk_hw *hw)
{
struct twl6040_clk *twl6040_clk = container_of(hw, struct twl6040_clk,
mcpdm_fclk);
int ret;
ret = twl6040_power(twl6040_clk->twl6040, 0);
if (!ret)
twl6040_clk->enabled = 0;
}
static const struct clk_ops twl6040_mcpdm_ops = {
.is_enabled = twl6040_bitclk_is_enabled,
.prepare = twl6040_bitclk_prepare,
.unprepare = twl6040_bitclk_unprepare,
};
static struct clk_init_data wm831x_clkout_init = {
.name = "mcpdm_fclk",
.ops = &twl6040_mcpdm_ops,
.flags = CLK_IS_ROOT,
};
static int __devinit twl6040_clk_probe(struct platform_device *pdev)
{
struct twl6040 *twl6040 = dev_get_drvdata(pdev->dev.parent);
struct twl6040_clk *clkdata;
clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
if (!clkdata)
return -ENOMEM;
clkdata->dev = &pdev->dev;
clkdata->twl6040 = twl6040;
clkdata->mcpdm_fclk.init = &wm831x_clkout_init;
clkdata->clk = clk_register(&pdev->dev, &clkdata->mcpdm_fclk);
if (!clkdata->clk)
return -EINVAL;
dev_set_drvdata(&pdev->dev, clkdata);
return 0;
}
static int __devexit twl6040_clk_remove(struct platform_device *pdev)
{
struct twl6040_clk *clkdata = dev_get_drvdata(&pdev->dev);
clk_unregister(clkdata->clk);
return 0;
}
static struct platform_driver twl6040_clk_driver = {
.driver = {
.name = "twl6040-clk",
.owner = THIS_MODULE,
},
.probe = twl6040_clk_probe,
.remove = __devexit_p(twl6040_clk_remove),
};
module_platform_driver(twl6040_clk_driver);
MODULE_DESCRIPTION("TWL6040 clock driver for McPDM functional clock");
MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
MODULE_ALIAS("platform:twl6040-clk");
MODULE_LICENSE("GPL");