1/*
  2* TWL6040 clock module driver for OMAP4 McPDM functional clock
  3*
  4* Copyright (C) 2012 Texas Instruments Inc.
  5* Peter Ujfalusi <peter.ujfalusi@ti.com>
  6*
  7* This program is free software; you can redistribute it and/or
  8* modify it under the terms of the GNU General Public License
  9* version 2 as published by the Free Software Foundation.
 10*
 11* This program is distributed in the hope that it will be useful, but
 12* WITHOUT ANY WARRANTY; without even the implied warranty of
 13* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 14* General Public License for more details.
 15*
 16* You should have received a copy of the GNU General Public License
 17* along with this program; if not, write to the Free Software
 18* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 19* 02110-1301 USA
 20*
 21*/
 22
 23#include <linux/module.h>
 24#include <linux/slab.h>
 25#include <linux/platform_device.h>
 26#include <linux/mfd/twl6040.h>
 27#include <linux/clk-provider.h>
 28
 29struct twl6040_pdmclk {
 30	struct twl6040 *twl6040;
 31	struct device *dev;
 32	struct clk_hw pdmclk_hw;
 33	int enabled;
 34};
 35
 36static int twl6040_pdmclk_is_prepared(struct clk_hw *hw)
 37{
 38	struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
 39						     pdmclk_hw);
 40
 41	return pdmclk->enabled;
 42}
 43
 44static int twl6040_pdmclk_prepare(struct clk_hw *hw)
 45{
 46	struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
 47						     pdmclk_hw);
 48	int ret;
 49
 50	ret = twl6040_power(pdmclk->twl6040, 1);
 51	if (!ret)
 52		pdmclk->enabled = 1;
 53
 54	return ret;
 55}
 56
 57static void twl6040_pdmclk_unprepare(struct clk_hw *hw)
 58{
 59	struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
 60						     pdmclk_hw);
 61	int ret;
 62
 63	ret = twl6040_power(pdmclk->twl6040, 0);
 64	if (!ret)
 65		pdmclk->enabled = 0;
 66
 67}
 68
 69static unsigned long twl6040_pdmclk_recalc_rate(struct clk_hw *hw,
 70						unsigned long parent_rate)
 71{
 72	struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
 73						     pdmclk_hw);
 74
 75	return twl6040_get_sysclk(pdmclk->twl6040);
 76}
 77
 78static const struct clk_ops twl6040_pdmclk_ops = {
 79	.is_prepared = twl6040_pdmclk_is_prepared,
 80	.prepare = twl6040_pdmclk_prepare,
 81	.unprepare = twl6040_pdmclk_unprepare,
 82	.recalc_rate = twl6040_pdmclk_recalc_rate,
 83};
 84
 85static const struct clk_init_data twl6040_pdmclk_init = {
 86	.name = "pdmclk",
 87	.ops = &twl6040_pdmclk_ops,
 88	.flags = CLK_GET_RATE_NOCACHE,
 89};
 90
 91static int twl6040_pdmclk_probe(struct platform_device *pdev)
 92{
 93	struct twl6040 *twl6040 = dev_get_drvdata(pdev->dev.parent);
 94	struct twl6040_pdmclk *clkdata;
 95	int ret;
 96
 97	clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
 98	if (!clkdata)
 99		return -ENOMEM;
100
101	clkdata->dev = &pdev->dev;
102	clkdata->twl6040 = twl6040;
103
104	clkdata->pdmclk_hw.init = &twl6040_pdmclk_init;
105	ret = devm_clk_hw_register(&pdev->dev, &clkdata->pdmclk_hw);
106	if (ret)
107		return ret;
108
109	platform_set_drvdata(pdev, clkdata);
110
111	return of_clk_add_hw_provider(pdev->dev.parent->of_node,
112				      of_clk_hw_simple_get,
113				      &clkdata->pdmclk_hw);
114}
115
116static struct platform_driver twl6040_pdmclk_driver = {
117	.driver = {
118		.name = "twl6040-pdmclk",
119	},
120	.probe = twl6040_pdmclk_probe,
121};
122
123module_platform_driver(twl6040_pdmclk_driver);
124
125MODULE_DESCRIPTION("TWL6040 clock driver for McPDM functional clock");
126MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
127MODULE_ALIAS("platform:twl6040-pdmclk");
128MODULE_LICENSE("GPL");