Revision 761bfb999868c413aabed8caa345694836ec6f11 authored by Alex Deucher on 06 August 2013, 17:34:00 UTC, committed by Alex Deucher on 07 August 2013, 21:37:19 UTC
The rlc is required for dpm to work properly, so if
the rlc ucode is missing, don't enable dpm.  Enabling
dpm without the rlc enabled can result in hangs.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
1 parent f61d5b4
Raw File
clk-wm831x.c
/*
 * WM831x clock control
 *
 * Copyright 2011-2 Wolfson Microelectronics PLC.
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.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.
 *
 */

#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/mfd/wm831x/core.h>

struct wm831x_clk {
	struct wm831x *wm831x;
	struct clk_hw xtal_hw;
	struct clk_hw fll_hw;
	struct clk_hw clkout_hw;
	struct clk *xtal;
	struct clk *fll;
	struct clk *clkout;
	bool xtal_ena;
};

static int wm831x_xtal_is_enabled(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  xtal_hw);

	return clkdata->xtal_ena;
}

static unsigned long wm831x_xtal_recalc_rate(struct clk_hw *hw,
					     unsigned long parent_rate)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  xtal_hw);

	if (clkdata->xtal_ena)
		return 32768;
	else
		return 0;
}

static const struct clk_ops wm831x_xtal_ops = {
	.is_enabled = wm831x_xtal_is_enabled,
	.recalc_rate = wm831x_xtal_recalc_rate,
};

static struct clk_init_data wm831x_xtal_init = {
	.name = "xtal",
	.ops = &wm831x_xtal_ops,
	.flags = CLK_IS_ROOT,
};

static const unsigned long wm831x_fll_auto_rates[] = {
	 2048000,
	11289600,
	12000000,
	12288000,
	19200000,
	22579600,
	24000000,
	24576000,
};

static int wm831x_fll_is_enabled(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  fll_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_1);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read FLL_CONTROL_1: %d\n",
			ret);
		return true;
	}

	return (ret & WM831X_FLL_ENA) != 0;
}

static int wm831x_fll_prepare(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  fll_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_1,
			      WM831X_FLL_ENA, WM831X_FLL_ENA);
	if (ret != 0)
		dev_crit(wm831x->dev, "Failed to enable FLL: %d\n", ret);

	usleep_range(2000, 2000);

	return ret;
}

static void wm831x_fll_unprepare(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  fll_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_1, WM831X_FLL_ENA, 0);
	if (ret != 0)
		dev_crit(wm831x->dev, "Failed to disable FLL: %d\n", ret);
}

static unsigned long wm831x_fll_recalc_rate(struct clk_hw *hw,
					    unsigned long parent_rate)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  fll_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
			ret);
		return 0;
	}

	if (ret & WM831X_FLL_AUTO)
		return wm831x_fll_auto_rates[ret & WM831X_FLL_AUTO_FREQ_MASK];

	dev_err(wm831x->dev, "FLL only supported in AUTO mode\n");

	return 0;
}

static long wm831x_fll_round_rate(struct clk_hw *hw, unsigned long rate,
				  unsigned long *unused)
{
	int best = 0;
	int i;

	for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++)
		if (abs(wm831x_fll_auto_rates[i] - rate) <
		    abs(wm831x_fll_auto_rates[best] - rate))
			best = i;

	return wm831x_fll_auto_rates[best];
}

static int wm831x_fll_set_rate(struct clk_hw *hw, unsigned long rate,
			       unsigned long parent_rate)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  fll_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int i;

	for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++)
		if (wm831x_fll_auto_rates[i] == rate)
			break;
	if (i == ARRAY_SIZE(wm831x_fll_auto_rates))
		return -EINVAL;

	if (wm831x_fll_is_enabled(hw))
		return -EPERM;

	return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_2,
			       WM831X_FLL_AUTO_FREQ_MASK, i);
}

static const char *wm831x_fll_parents[] = {
	"xtal",
	"clkin",
};

static u8 wm831x_fll_get_parent(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  fll_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	/* AUTO mode is always clocked from the crystal */
	ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
			ret);
		return 0;
	}

	if (ret & WM831X_FLL_AUTO)
		return 0;

	ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_5);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read FLL_CONTROL_5: %d\n",
			ret);
		return 0;
	}

	switch (ret & WM831X_FLL_CLK_SRC_MASK) {
	case 0:
		return 0;
	case 1:
		return 1;
	default:
		dev_err(wm831x->dev, "Unsupported FLL clock source %d\n",
			ret & WM831X_FLL_CLK_SRC_MASK);
		return 0;
	}
}

static const struct clk_ops wm831x_fll_ops = {
	.is_enabled = wm831x_fll_is_enabled,
	.prepare = wm831x_fll_prepare,
	.unprepare = wm831x_fll_unprepare,
	.round_rate = wm831x_fll_round_rate,
	.recalc_rate = wm831x_fll_recalc_rate,
	.set_rate = wm831x_fll_set_rate,
	.get_parent = wm831x_fll_get_parent,
};

static struct clk_init_data wm831x_fll_init = {
	.name = "fll",
	.ops = &wm831x_fll_ops,
	.parent_names = wm831x_fll_parents,
	.num_parents = ARRAY_SIZE(wm831x_fll_parents),
	.flags = CLK_SET_RATE_GATE,
};

static int wm831x_clkout_is_enabled(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  clkout_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n",
			ret);
		return true;
	}

	return (ret & WM831X_CLKOUT_ENA) != 0;
}

static int wm831x_clkout_prepare(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  clkout_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_reg_unlock(wm831x);
	if (ret != 0) {
		dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret);
		return ret;
	}

	ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
			      WM831X_CLKOUT_ENA, WM831X_CLKOUT_ENA);
	if (ret != 0)
		dev_crit(wm831x->dev, "Failed to enable CLKOUT: %d\n", ret);

	wm831x_reg_lock(wm831x);

	return ret;
}

static void wm831x_clkout_unprepare(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  clkout_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_reg_unlock(wm831x);
	if (ret != 0) {
		dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret);
		return;
	}

	ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
			      WM831X_CLKOUT_ENA, 0);
	if (ret != 0)
		dev_crit(wm831x->dev, "Failed to disable CLKOUT: %d\n", ret);

	wm831x_reg_lock(wm831x);
}

static const char *wm831x_clkout_parents[] = {
	"fll",
	"xtal",
};

static u8 wm831x_clkout_get_parent(struct clk_hw *hw)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  clkout_hw);
	struct wm831x *wm831x = clkdata->wm831x;
	int ret;

	ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n",
			ret);
		return 0;
	}

	if (ret & WM831X_CLKOUT_SRC)
		return 1;
	else
		return 0;
}

static int wm831x_clkout_set_parent(struct clk_hw *hw, u8 parent)
{
	struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
						  clkout_hw);
	struct wm831x *wm831x = clkdata->wm831x;

	return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
			       WM831X_CLKOUT_SRC,
			       parent << WM831X_CLKOUT_SRC_SHIFT);
}

static const struct clk_ops wm831x_clkout_ops = {
	.is_enabled = wm831x_clkout_is_enabled,
	.prepare = wm831x_clkout_prepare,
	.unprepare = wm831x_clkout_unprepare,
	.get_parent = wm831x_clkout_get_parent,
	.set_parent = wm831x_clkout_set_parent,
};

static struct clk_init_data wm831x_clkout_init = {
	.name = "clkout",
	.ops = &wm831x_clkout_ops,
	.parent_names = wm831x_clkout_parents,
	.num_parents = ARRAY_SIZE(wm831x_clkout_parents),
	.flags = CLK_SET_RATE_PARENT,
};

static int wm831x_clk_probe(struct platform_device *pdev)
{
	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
	struct wm831x_clk *clkdata;
	int ret;

	clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
	if (!clkdata)
		return -ENOMEM;

	/* XTAL_ENA can only be set via OTP/InstantConfig so just read once */
	ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
	if (ret < 0) {
		dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
			ret);
		return ret;
	}
	clkdata->xtal_ena = ret & WM831X_XTAL_ENA;

	clkdata->xtal_hw.init = &wm831x_xtal_init;
	clkdata->xtal = devm_clk_register(&pdev->dev, &clkdata->xtal_hw);
	if (IS_ERR(clkdata->xtal))
		return PTR_ERR(clkdata->xtal);

	clkdata->fll_hw.init = &wm831x_fll_init;
	clkdata->fll = devm_clk_register(&pdev->dev, &clkdata->fll_hw);
	if (IS_ERR(clkdata->fll))
		return PTR_ERR(clkdata->fll);

	clkdata->clkout_hw.init = &wm831x_clkout_init;
	clkdata->clkout = devm_clk_register(&pdev->dev, &clkdata->clkout_hw);
	if (IS_ERR(clkdata->clkout))
		return PTR_ERR(clkdata->clkout);

	platform_set_drvdata(pdev, clkdata);

	return 0;
}

static int wm831x_clk_remove(struct platform_device *pdev)
{
	return 0;
}

static struct platform_driver wm831x_clk_driver = {
	.probe = wm831x_clk_probe,
	.remove = wm831x_clk_remove,
	.driver		= {
		.name	= "wm831x-clk",
		.owner	= THIS_MODULE,
	},
};

module_platform_driver(wm831x_clk_driver);

/* Module information */
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("WM831x clock driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-clk");
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