Commit 4cfaa55f authored by Tirupathi Reddy's avatar Tirupathi Reddy Committed by Stephen Boyd
Browse files

clk: qcom: Add spmi_pmic clock divider support 



Clkdiv module provides a clock output on the PMIC with CXO as
the source. This clock can be routed through PMIC GPIOs. Add
a device driver to configure this clkdiv module.

Signed-off-by: default avatarTirupathi Reddy <tirupath@codeaurora.org>
[sboyd: Simplified code and moved to devm clk provider APIs]
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
parent e3447a67

drivers/clk/qcom/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -196,3 +196,12 @@ config MSM_MMCC_8996 
	  Support for the multimedia clock controller on msm8996 devices.

	  Say Y if you want to support multimedia devices such as display,

	  graphics, video encode/decode, camera, etc.



config SPMI_PMIC_CLKDIV

	tristate "SPMI PMIC clkdiv Support"

	depends on (COMMON_CLK_QCOM && SPMI) || COMPILE_TEST

	help

	  This driver supports the clkdiv functionality on the Qualcomm

	  Technologies, Inc. SPMI PMIC. It configures the frequency of

	  clkdiv outputs of the PMIC. These clocks are typically wired

	  through alternate functions on GPIO pins.

drivers/clk/qcom/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -34,3 +34,4 @@ obj-$(CONFIG_MSM_MMCC_8974) += mmcc-msm8974.o 
obj-$(CONFIG_MSM_MMCC_8996) += mmcc-msm8996.o

obj-$(CONFIG_QCOM_CLK_RPM) += clk-rpm.o

obj-$(CONFIG_QCOM_CLK_SMD_RPM) += clk-smd-rpm.o

obj-$(CONFIG_SPMI_PMIC_CLKDIV) += clk-spmi-pmic-div.o

drivers/clk/qcom/clk-spmi-pmic-div.c

0 → 100644
+302 −0
Original line number Diff line number Diff line 
/* Copyright (c) 2017, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only 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.

 */



#include <linux/bitops.h>

#include <linux/clk.h>

#include <linux/clk-provider.h>

#include <linux/delay.h>

#include <linux/err.h>

#include <linux/log2.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/regmap.h>

#include <linux/slab.h>

#include <linux/types.h>



#define REG_DIV_CTL1			0x43

#define DIV_CTL1_DIV_FACTOR_MASK	GENMASK(2, 0)



#define REG_EN_CTL			0x46

#define REG_EN_MASK			BIT(7)



struct clkdiv {

	struct regmap		*regmap;

	u16			base;

	spinlock_t		lock;



	struct clk_hw		hw;

	unsigned int		cxo_period_ns;

};



static inline struct clkdiv *to_clkdiv(struct clk_hw *hw)

{

	return container_of(hw, struct clkdiv, hw);

}



static inline unsigned int div_factor_to_div(unsigned int div_factor)

{

	if (!div_factor)

		div_factor = 1;



	return 1 << (div_factor - 1);

}



static inline unsigned int div_to_div_factor(unsigned int div)

{

	return min(ilog2(div) + 1, 7);

}



static bool is_spmi_pmic_clkdiv_enabled(struct clkdiv *clkdiv)

{

	unsigned int val = 0;



	regmap_read(clkdiv->regmap, clkdiv->base + REG_EN_CTL, &val);



	return val & REG_EN_MASK;

}



static int

__spmi_pmic_clkdiv_set_enable_state(struct clkdiv *clkdiv, bool enable,

				    unsigned int div_factor)

{

	int ret;

	unsigned int ns = clkdiv->cxo_period_ns;

	unsigned int div = div_factor_to_div(div_factor);



	ret = regmap_update_bits(clkdiv->regmap, clkdiv->base + REG_EN_CTL,

				 REG_EN_MASK, enable ? REG_EN_MASK : 0);

	if (ret)

		return ret;



	if (enable)

		ndelay((2 + 3 * div) * ns);

	else

		ndelay(3 * div * ns);



	return 0;

}



static int spmi_pmic_clkdiv_set_enable_state(struct clkdiv *clkdiv, bool enable)

{

	unsigned int div_factor;



	regmap_read(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1, &div_factor);

	div_factor &= DIV_CTL1_DIV_FACTOR_MASK;



	return __spmi_pmic_clkdiv_set_enable_state(clkdiv, enable, div_factor);

}



static int clk_spmi_pmic_div_enable(struct clk_hw *hw)

{

	struct clkdiv *clkdiv = to_clkdiv(hw);

	unsigned long flags;

	int ret;



	spin_lock_irqsave(&clkdiv->lock, flags);

	ret = spmi_pmic_clkdiv_set_enable_state(clkdiv, true);

	spin_unlock_irqrestore(&clkdiv->lock, flags);



	return ret;

}



static void clk_spmi_pmic_div_disable(struct clk_hw *hw)

{

	struct clkdiv *clkdiv = to_clkdiv(hw);

	unsigned long flags;



	spin_lock_irqsave(&clkdiv->lock, flags);

	spmi_pmic_clkdiv_set_enable_state(clkdiv, false);

	spin_unlock_irqrestore(&clkdiv->lock, flags);

}



static long clk_spmi_pmic_div_round_rate(struct clk_hw *hw, unsigned long rate,

					 unsigned long *parent_rate)

{

	unsigned int div, div_factor;



	div = DIV_ROUND_UP(*parent_rate, rate);

	div_factor = div_to_div_factor(div);

	div = div_factor_to_div(div_factor);



	return *parent_rate / div;

}



static unsigned long

clk_spmi_pmic_div_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)

{

	struct clkdiv *clkdiv = to_clkdiv(hw);

	unsigned int div_factor;



	regmap_read(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1, &div_factor);

	div_factor &= DIV_CTL1_DIV_FACTOR_MASK;



	return parent_rate / div_factor_to_div(div_factor);

}



static int clk_spmi_pmic_div_set_rate(struct clk_hw *hw, unsigned long rate,

				      unsigned long parent_rate)

{

	struct clkdiv *clkdiv = to_clkdiv(hw);

	unsigned int div_factor = div_to_div_factor(parent_rate / rate);

	unsigned long flags;

	bool enabled;

	int ret;



	spin_lock_irqsave(&clkdiv->lock, flags);

	enabled = is_spmi_pmic_clkdiv_enabled(clkdiv);

	if (enabled) {

		ret = spmi_pmic_clkdiv_set_enable_state(clkdiv, false);

		if (ret)

			goto unlock;

	}



	ret = regmap_update_bits(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1,

				 DIV_CTL1_DIV_FACTOR_MASK, div_factor);

	if (ret)

		goto unlock;



	if (enabled)

		ret = __spmi_pmic_clkdiv_set_enable_state(clkdiv, true,

							  div_factor);



unlock:

	spin_unlock_irqrestore(&clkdiv->lock, flags);



	return ret;

}



static const struct clk_ops clk_spmi_pmic_div_ops = {

	.enable = clk_spmi_pmic_div_enable,

	.disable = clk_spmi_pmic_div_disable,

	.set_rate = clk_spmi_pmic_div_set_rate,

	.recalc_rate = clk_spmi_pmic_div_recalc_rate,

	.round_rate = clk_spmi_pmic_div_round_rate,

};



struct spmi_pmic_div_clk_cc {

	int		nclks;

	struct clkdiv	clks[];

};



static struct clk_hw *

spmi_pmic_div_clk_hw_get(struct of_phandle_args *clkspec, void *data)

{

	struct spmi_pmic_div_clk_cc *cc = data;

	int idx = clkspec->args[0] - 1; /* Start at 1 instead of 0 */



	if (idx < 0 || idx >= cc->nclks) {

		pr_err("%s: index value %u is invalid; allowed range [1, %d]\n",

		       __func__, clkspec->args[0], cc->nclks);

		return ERR_PTR(-EINVAL);

	}



	return &cc->clks[idx].hw;

}



static int spmi_pmic_clkdiv_probe(struct platform_device *pdev)

{

	struct spmi_pmic_div_clk_cc *cc;

	struct clk_init_data init = {};

	struct clkdiv *clkdiv;

	struct clk *cxo;

	struct regmap *regmap;

	struct device *dev = &pdev->dev;

	struct device_node *of_node = dev->of_node;

	const char *parent_name;

	int nclks, i, ret, cxo_hz;

	char name[20];

	u32 start;



	ret = of_property_read_u32(of_node, "reg", &start);

	if (ret < 0) {

		dev_err(dev, "reg property reading failed\n");

		return ret;

	}



	regmap = dev_get_regmap(dev->parent, NULL);

	if (!regmap) {

		dev_err(dev, "Couldn't get parent's regmap\n");

		return -EINVAL;

	}



	ret = of_property_read_u32(of_node, "qcom,num-clkdivs", &nclks);

	if (ret < 0) {

		dev_err(dev, "qcom,num-clkdivs property reading failed, ret=%d\n",

			ret);

		return ret;

	}



	if (!nclks)

		return -EINVAL;



	cc = devm_kzalloc(dev, sizeof(*cc) + sizeof(*cc->clks) * nclks,

			  GFP_KERNEL);

	if (!cc)

		return -ENOMEM;

	cc->nclks = nclks;



	cxo = clk_get(dev, "xo");

	if (IS_ERR(cxo)) {

		ret = PTR_ERR(cxo);

		if (ret != -EPROBE_DEFER)

			dev_err(dev, "failed to get xo clock\n");

		return ret;

	}

	cxo_hz = clk_get_rate(cxo);

	clk_put(cxo);



	parent_name = of_clk_get_parent_name(of_node, 0);

	if (!parent_name) {

		dev_err(dev, "missing parent clock\n");

		return -ENODEV;

	}



	init.name = name;

	init.parent_names = &parent_name;

	init.num_parents = 1;

	init.ops = &clk_spmi_pmic_div_ops;



	for (i = 0, clkdiv = cc->clks; i < nclks; i++) {

		snprintf(name, sizeof(name), "div_clk%d", i + 1);



		spin_lock_init(&clkdiv[i].lock);

		clkdiv[i].base = start + i * 0x100;

		clkdiv[i].regmap = regmap;

		clkdiv[i].cxo_period_ns = NSEC_PER_SEC / cxo_hz;

		clkdiv[i].hw.init = &init;



		ret = devm_clk_hw_register(dev, &clkdiv[i].hw);

		if (ret)

			return ret;

	}



	return devm_of_clk_add_hw_provider(dev, spmi_pmic_div_clk_hw_get, cc);

}



static const struct of_device_id spmi_pmic_clkdiv_match_table[] = {

	{ .compatible = "qcom,spmi-clkdiv" },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, spmi_pmic_clkdiv_match_table);



static struct platform_driver spmi_pmic_clkdiv_driver = {

	.driver		= {

		.name	= "qcom,spmi-pmic-clkdiv",

		.of_match_table = spmi_pmic_clkdiv_match_table,

	},

	.probe		= spmi_pmic_clkdiv_probe,

};

module_platform_driver(spmi_pmic_clkdiv_driver);



MODULE_DESCRIPTION("QCOM SPMI PMIC clkdiv driver");

MODULE_LICENSE("GPL v2");

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