linux-imx

/*

* 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/module.h>

#include <linux/slab.h>

#include <linux/platform_device.h>

#include <linux/mfd/twl6040.h>

#include <linux/clk-provider.h>

​

struct twl6040_pdmclk {

    struct twl6040 *twl6040;

    struct device *dev;

    struct clk_hw pdmclk_hw;

    int enabled;

};

​

static int twl6040_pdmclk_is_prepared(struct clk_hw *hw)

{

    struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,

                             pdmclk_hw);

​

    return pdmclk->enabled;

}

​

static int twl6040_pdmclk_reset_one_clock(struct twl6040_pdmclk *pdmclk,

                      unsigned int reg)

{

    const u8 reset_mask = TWL6040_HPLLRST;  /* Same for HPPLL and LPPLL */

    int ret;

​

    ret = twl6040_set_bits(pdmclk->twl6040, reg, reset_mask);

    if (ret < 0)

        return ret;

​

    ret = twl6040_clear_bits(pdmclk->twl6040, reg, reset_mask);

    if (ret < 0)

        return ret;

​

    return 0;

}

​

/*

 * TWL6040A2 Phoenix Audio IC erratum #6: "PDM Clock Generation Issue At

 * Cold Temperature". This affects cold boot and deeper idle states it