drivers/mfd/ti_am335x_tscadc.c - kernel/common - Git at Google

 /*
  * TI Touch Screen / ADC MFD driver
  *
  * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.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 version 2.
  *
  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
  * kind, whether express or implied; without even the implied warranty
  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/clk.h>
 #include <linux/regmap.h>
 #include <linux/mfd/core.h>
 #include <linux/pm_runtime.h>
 #include <linux/of.h>
 #include <linux/of_device.h>

 #include <linux/mfd/ti_am335x_tscadc.h>

 static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
 {
 	unsigned int val;

 	regmap_read(tsadc->regmap_tscadc, reg, &val);
 	return val;
 }

 static void tscadc_writel(struct ti_tscadc_dev *tsadc, unsigned int reg,
 					unsigned int val)
 {
 	regmap_write(tsadc->regmap_tscadc, reg, val);
 }

 static const struct regmap_config tscadc_regmap_config = {
 	.name = "ti_tscadc",
 	.reg_bits = 32,
 	.reg_stride = 4,
 	.val_bits = 32,
 };

 void am335x_tsc_se_update(struct ti_tscadc_dev *tsadc)
 {
 	tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
 }
 EXPORT_SYMBOL_GPL(am335x_tsc_se_update);

 void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val)
 {
 	spin_lock(&tsadc->reg_lock);
 	tsadc->reg_se_cache |= val;
 	spin_unlock(&tsadc->reg_lock);

 	am335x_tsc_se_update(tsadc);
 }
 EXPORT_SYMBOL_GPL(am335x_tsc_se_set);

 void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val)
 {
 	spin_lock(&tsadc->reg_lock);
 	tsadc->reg_se_cache &= ~val;
 	spin_unlock(&tsadc->reg_lock);

 	am335x_tsc_se_update(tsadc);
 }
 EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);

 static void tscadc_idle_config(struct ti_tscadc_dev *config)
 {
 	unsigned int idleconfig;

 	idleconfig = STEPCONFIG_YNN | STEPCONFIG_INM_ADCREFM |
 			STEPCONFIG_INP_ADCREFM | STEPCONFIG_YPN;

 	tscadc_writel(config, REG_IDLECONFIG, idleconfig);
 }

 static	int ti_tscadc_probe(struct platform_device *pdev)
 {
 	struct ti_tscadc_dev	*tscadc;
 	struct resource		*res;
 	struct clk		*clk;
 	struct device_node	*node = pdev->dev.of_node;
 	struct mfd_cell		*cell;
 	struct property         *prop;
 	const __be32            *cur;
 	u32			val;
 	int			err, ctrl;
 	int			clk_value, clock_rate;
 	int			tsc_wires = 0, adc_channels = 0, total_channels;
 	int			readouts = 0;

 	if (!pdev->dev.of_node) {
 		dev_err(&pdev->dev, "Could not find valid DT data.\n");
 		return -EINVAL;
 	}

 	node = of_get_child_by_name(pdev->dev.of_node, "tsc");
 	of_property_read_u32(node, "ti,wires", &tsc_wires);
 	of_property_read_u32(node, "ti,coordiante-readouts", &readouts);

 	node = of_get_child_by_name(pdev->dev.of_node, "adc");
 	of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
 		adc_channels++;
 		if (val > 7) {
 			dev_err(&pdev->dev, " PIN numbers are 0..7 (not %d)\n",
 					val);
 			return -EINVAL;
 		}
 	}
 	total_channels = tsc_wires + adc_channels;
 	if (total_channels > 8) {
 		dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
 		return -EINVAL;
 	}
 	if (total_channels == 0) {
 		dev_err(&pdev->dev, "Need atleast one channel.\n");
 		return -EINVAL;
 	}

 	if (readouts * 2 + 2 + adc_channels > 16) {
 		dev_err(&pdev->dev, "Too many step configurations requested\n");
 		return -EINVAL;
 	}

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		dev_err(&pdev->dev, "no memory resource defined.\n");
 		return -EINVAL;
 	}

 	/* Allocate memory for device */
 	tscadc = devm_kzalloc(&pdev->dev,
 			sizeof(struct ti_tscadc_dev), GFP_KERNEL);
 	if (!tscadc) {
 		dev_err(&pdev->dev, "failed to allocate memory.\n");
 		return -ENOMEM;
 	}
 	tscadc->dev = &pdev->dev;

 	err = platform_get_irq(pdev, 0);
 	if (err < 0) {
 		dev_err(&pdev->dev, "no irq ID is specified.\n");
 		goto ret;
 	} else
 		tscadc->irq = err;

 	res = devm_request_mem_region(&pdev->dev,
 			res->start, resource_size(res), pdev->name);
 	if (!res) {
 		dev_err(&pdev->dev, "failed to reserve registers.\n");
 		return -EBUSY;
 	}

 	tscadc->tscadc_base = devm_ioremap(&pdev->dev,
 			res->start, resource_size(res));
 	if (!tscadc->tscadc_base) {
 		dev_err(&pdev->dev, "failed to map registers.\n");
 		return -ENOMEM;
 	}

 	tscadc->regmap_tscadc = devm_regmap_init_mmio(&pdev->dev,
 			tscadc->tscadc_base, &tscadc_regmap_config);
 	if (IS_ERR(tscadc->regmap_tscadc)) {
 		dev_err(&pdev->dev, "regmap init failed\n");
 		err = PTR_ERR(tscadc->regmap_tscadc);
 		goto ret;
 	}

 	spin_lock_init(&tscadc->reg_lock);
 	pm_runtime_enable(&pdev->dev);
 	pm_runtime_get_sync(&pdev->dev);

 	/*
 	 * The TSC_ADC_Subsystem has 2 clock domains
 	 * OCP_CLK and ADC_CLK.
 	 * The ADC clock is expected to run at target of 3MHz,
 	 * and expected to capture 12-bit data at a rate of 200 KSPS.
 	 * The TSC_ADC_SS controller design assumes the OCP clock is
 	 * at least 6x faster than the ADC clock.
 	 */
 	clk = clk_get(&pdev->dev, "adc_tsc_fck");
 	if (IS_ERR(clk)) {
 		dev_err(&pdev->dev, "failed to get TSC fck\n");
 		err = PTR_ERR(clk);
 		goto err_disable_clk;
 	}
 	clock_rate = clk_get_rate(clk);
 	clk_put(clk);
 	clk_value = clock_rate / ADC_CLK;
 	if (clk_value < MAX_CLK_DIV) {
 		dev_err(&pdev->dev, "clock input less than min clock requirement\n");
 		err = -EINVAL;
 		goto err_disable_clk;
 	}
 	/* TSCADC_CLKDIV needs to be configured to the value minus 1 */
 	clk_value = clk_value - 1;
 	tscadc_writel(tscadc, REG_CLKDIV, clk_value);

 	/* Set the control register bits */
 	ctrl = CNTRLREG_STEPCONFIGWRT |
 			CNTRLREG_TSCENB |
 			CNTRLREG_STEPID |
 			CNTRLREG_4WIRE;
 	tscadc_writel(tscadc, REG_CTRL, ctrl);

 	/* Set register bits for Idle Config Mode */
 	tscadc_idle_config(tscadc);

 	/* Enable the TSC module enable bit */
 	ctrl = tscadc_readl(tscadc, REG_CTRL);
 	ctrl |= CNTRLREG_TSCSSENB;
 	tscadc_writel(tscadc, REG_CTRL, ctrl);

 	tscadc->used_cells = 0;
 	tscadc->tsc_cell = -1;
 	tscadc->adc_cell = -1;

 	/* TSC Cell */
 	if (tsc_wires > 0) {
 		tscadc->tsc_cell = tscadc->used_cells;
 		cell = &tscadc->cells[tscadc->used_cells++];
 		cell->name = "TI-am335x-tsc";
 		cell->of_compatible = "ti,am3359-tsc";
 		cell->platform_data = &tscadc;
 		cell->pdata_size = sizeof(tscadc);
 	}

 	/* ADC Cell */
 	if (adc_channels > 0) {
 		tscadc->adc_cell = tscadc->used_cells;
 		cell = &tscadc->cells[tscadc->used_cells++];
 		cell->name = "TI-am335x-adc";
 		cell->of_compatible = "ti,am3359-adc";
 		cell->platform_data = &tscadc;
 		cell->pdata_size = sizeof(tscadc);
 	}

 	err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
 			tscadc->used_cells, NULL, 0, NULL);
 	if (err < 0)
 		goto err_disable_clk;

 	device_init_wakeup(&pdev->dev, true);
 	platform_set_drvdata(pdev, tscadc);
 	return 0;

 err_disable_clk:
 	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 ret:
 	return err;
 }

 static int ti_tscadc_remove(struct platform_device *pdev)
 {
 	struct ti_tscadc_dev	*tscadc = platform_get_drvdata(pdev);

 	tscadc_writel(tscadc, REG_SE, 0x00);

 	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);

 	mfd_remove_devices(tscadc->dev);

 	return 0;
 }

 #ifdef CONFIG_PM
 static int tscadc_suspend(struct device *dev)
 {
 	struct ti_tscadc_dev	*tscadc_dev = dev_get_drvdata(dev);

 	tscadc_writel(tscadc_dev, REG_SE, 0x00);
 	pm_runtime_put_sync(dev);

 	return 0;
 }

 static int tscadc_resume(struct device *dev)
 {
 	struct ti_tscadc_dev	*tscadc_dev = dev_get_drvdata(dev);
 	unsigned int restore, ctrl;

 	pm_runtime_get_sync(dev);

 	/* context restore */
 	ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_TSCENB |
 			CNTRLREG_STEPID | CNTRLREG_4WIRE;
 	tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
 	tscadc_idle_config(tscadc_dev);
 	am335x_tsc_se_update(tscadc_dev);
 	restore = tscadc_readl(tscadc_dev, REG_CTRL);
 	tscadc_writel(tscadc_dev, REG_CTRL,
 			(restore | CNTRLREG_TSCSSENB));

 	return 0;
 }

 static const struct dev_pm_ops tscadc_pm_ops = {
 	.suspend = tscadc_suspend,
 	.resume = tscadc_resume,
 };
 #define TSCADC_PM_OPS (&tscadc_pm_ops)
 #else
 #define TSCADC_PM_OPS NULL
 #endif

 static const struct of_device_id ti_tscadc_dt_ids[] = {
 	{ .compatible = "ti,am3359-tscadc", },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids);

 static struct platform_driver ti_tscadc_driver = {
 	.driver = {
 		.name   = "ti_am3359-tscadc",
 		.owner	= THIS_MODULE,
 		.pm	= TSCADC_PM_OPS,
 		.of_match_table = of_match_ptr(ti_tscadc_dt_ids),
 	},
 	.probe	= ti_tscadc_probe,
 	.remove	= ti_tscadc_remove,

 };

 module_platform_driver(ti_tscadc_driver);

 MODULE_DESCRIPTION("TI touchscreen / ADC MFD controller driver");
 MODULE_AUTHOR("Rachna Patil <[email protected]>");
 MODULE_LICENSE("GPL");
	/*
	* TI Touch Screen / ADC MFD driver
	*
	* Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.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 version 2.
	*
	* This program is distributed "as is" WITHOUT ANY WARRANTY of any
	* kind, whether express or implied; without even the implied warranty
	* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/slab.h>
	#include <linux/err.h>
	#include <linux/io.h>
	#include <linux/clk.h>
	#include <linux/regmap.h>
	#include <linux/mfd/core.h>
	#include <linux/pm_runtime.h>
	#include <linux/of.h>
	#include <linux/of_device.h>

	#include <linux/mfd/ti_am335x_tscadc.h>

	static unsigned int tscadc_readl(struct ti_tscadc_dev *tsadc, unsigned int reg)
	{
	unsigned int val;

	regmap_read(tsadc->regmap_tscadc, reg, &val);
	return val;
	}

	static void tscadc_writel(struct ti_tscadc_dev *tsadc, unsigned int reg,
	unsigned int val)
	{
	regmap_write(tsadc->regmap_tscadc, reg, val);
	}

	static const struct regmap_config tscadc_regmap_config = {
	.name = "ti_tscadc",
	.reg_bits = 32,
	.reg_stride = 4,
	.val_bits = 32,
	};

	void am335x_tsc_se_update(struct ti_tscadc_dev *tsadc)
	{
	tscadc_writel(tsadc, REG_SE, tsadc->reg_se_cache);
	}
	EXPORT_SYMBOL_GPL(am335x_tsc_se_update);

	void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val)
	{
	spin_lock(&tsadc->reg_lock);
	tsadc->reg_se_cache \|= val;
	spin_unlock(&tsadc->reg_lock);

	am335x_tsc_se_update(tsadc);
	}
	EXPORT_SYMBOL_GPL(am335x_tsc_se_set);

	void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val)
	{
	spin_lock(&tsadc->reg_lock);
	tsadc->reg_se_cache &= ~val;
	spin_unlock(&tsadc->reg_lock);

	am335x_tsc_se_update(tsadc);
	}
	EXPORT_SYMBOL_GPL(am335x_tsc_se_clr);

	static void tscadc_idle_config(struct ti_tscadc_dev *config)
	{
	unsigned int idleconfig;

	idleconfig = STEPCONFIG_YNN \| STEPCONFIG_INM_ADCREFM \|
	STEPCONFIG_INP_ADCREFM \| STEPCONFIG_YPN;

	tscadc_writel(config, REG_IDLECONFIG, idleconfig);
	}

	static int ti_tscadc_probe(struct platform_device *pdev)
	{
	struct ti_tscadc_dev *tscadc;
	struct resource *res;
	struct clk *clk;
	struct device_node *node = pdev->dev.of_node;
	struct mfd_cell *cell;
	struct property *prop;
	const __be32 *cur;
	u32 val;
	int err, ctrl;
	int clk_value, clock_rate;
	int tsc_wires = 0, adc_channels = 0, total_channels;
	int readouts = 0;

	if (!pdev->dev.of_node) {
	dev_err(&pdev->dev, "Could not find valid DT data.\n");
	return -EINVAL;
	}

	node = of_get_child_by_name(pdev->dev.of_node, "tsc");
	of_property_read_u32(node, "ti,wires", &tsc_wires);
	of_property_read_u32(node, "ti,coordiante-readouts", &readouts);

	node = of_get_child_by_name(pdev->dev.of_node, "adc");
	of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
	adc_channels++;
	if (val > 7) {
	dev_err(&pdev->dev, " PIN numbers are 0..7 (not %d)\n",
	val);
	return -EINVAL;
	}
	}
	total_channels = tsc_wires + adc_channels;
	if (total_channels > 8) {
	dev_err(&pdev->dev, "Number of i/p channels more than 8\n");
	return -EINVAL;
	}
	if (total_channels == 0) {
	dev_err(&pdev->dev, "Need atleast one channel.\n");
	return -EINVAL;
	}

	if (readouts * 2 + 2 + adc_channels > 16) {
	dev_err(&pdev->dev, "Too many step configurations requested\n");
	return -EINVAL;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
	dev_err(&pdev->dev, "no memory resource defined.\n");
	return -EINVAL;
	}

	/* Allocate memory for device */
	tscadc = devm_kzalloc(&pdev->dev,
	sizeof(struct ti_tscadc_dev), GFP_KERNEL);
	if (!tscadc) {
	dev_err(&pdev->dev, "failed to allocate memory.\n");
	return -ENOMEM;
	}
	tscadc->dev = &pdev->dev;

	err = platform_get_irq(pdev, 0);
	if (err < 0) {
	dev_err(&pdev->dev, "no irq ID is specified.\n");
	goto ret;
	} else
	tscadc->irq = err;

	res = devm_request_mem_region(&pdev->dev,
	res->start, resource_size(res), pdev->name);
	if (!res) {
	dev_err(&pdev->dev, "failed to reserve registers.\n");
	return -EBUSY;
	}

	tscadc->tscadc_base = devm_ioremap(&pdev->dev,
	res->start, resource_size(res));
	if (!tscadc->tscadc_base) {
	dev_err(&pdev->dev, "failed to map registers.\n");
	return -ENOMEM;
	}

	tscadc->regmap_tscadc = devm_regmap_init_mmio(&pdev->dev,
	tscadc->tscadc_base, &tscadc_regmap_config);
	if (IS_ERR(tscadc->regmap_tscadc)) {
	dev_err(&pdev->dev, "regmap init failed\n");
	err = PTR_ERR(tscadc->regmap_tscadc);
	goto ret;
	}

	spin_lock_init(&tscadc->reg_lock);
	pm_runtime_enable(&pdev->dev);
	pm_runtime_get_sync(&pdev->dev);

	/*
	* The TSC_ADC_Subsystem has 2 clock domains
	* OCP_CLK and ADC_CLK.
	* The ADC clock is expected to run at target of 3MHz,
	* and expected to capture 12-bit data at a rate of 200 KSPS.
	* The TSC_ADC_SS controller design assumes the OCP clock is
	* at least 6x faster than the ADC clock.
	*/
	clk = clk_get(&pdev->dev, "adc_tsc_fck");
	if (IS_ERR(clk)) {
	dev_err(&pdev->dev, "failed to get TSC fck\n");
	err = PTR_ERR(clk);
	goto err_disable_clk;
	}
	clock_rate = clk_get_rate(clk);
	clk_put(clk);
	clk_value = clock_rate / ADC_CLK;
	if (clk_value < MAX_CLK_DIV) {
	dev_err(&pdev->dev, "clock input less than min clock requirement\n");
	err = -EINVAL;
	goto err_disable_clk;
	}
	/* TSCADC_CLKDIV needs to be configured to the value minus 1 */
	clk_value = clk_value - 1;
	tscadc_writel(tscadc, REG_CLKDIV, clk_value);

	/* Set the control register bits */
	ctrl = CNTRLREG_STEPCONFIGWRT \|
	CNTRLREG_TSCENB \|
	CNTRLREG_STEPID \|
	CNTRLREG_4WIRE;
	tscadc_writel(tscadc, REG_CTRL, ctrl);

	/* Set register bits for Idle Config Mode */
	tscadc_idle_config(tscadc);

	/* Enable the TSC module enable bit */
	ctrl = tscadc_readl(tscadc, REG_CTRL);
	ctrl \|= CNTRLREG_TSCSSENB;
	tscadc_writel(tscadc, REG_CTRL, ctrl);

	tscadc->used_cells = 0;
	tscadc->tsc_cell = -1;
	tscadc->adc_cell = -1;

	/* TSC Cell */
	if (tsc_wires > 0) {
	tscadc->tsc_cell = tscadc->used_cells;
	cell = &tscadc->cells[tscadc->used_cells++];
	cell->name = "TI-am335x-tsc";
	cell->of_compatible = "ti,am3359-tsc";
	cell->platform_data = &tscadc;
	cell->pdata_size = sizeof(tscadc);
	}

	/* ADC Cell */
	if (adc_channels > 0) {
	tscadc->adc_cell = tscadc->used_cells;
	cell = &tscadc->cells[tscadc->used_cells++];
	cell->name = "TI-am335x-adc";
	cell->of_compatible = "ti,am3359-adc";
	cell->platform_data = &tscadc;
	cell->pdata_size = sizeof(tscadc);
	}

	err = mfd_add_devices(&pdev->dev, pdev->id, tscadc->cells,
	tscadc->used_cells, NULL, 0, NULL);
	if (err < 0)
	goto err_disable_clk;

	device_init_wakeup(&pdev->dev, true);
	platform_set_drvdata(pdev, tscadc);
	return 0;

	err_disable_clk:
	pm_runtime_put_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);
	ret:
	return err;
	}

	static int ti_tscadc_remove(struct platform_device *pdev)
	{
	struct ti_tscadc_dev *tscadc = platform_get_drvdata(pdev);

	tscadc_writel(tscadc, REG_SE, 0x00);

	pm_runtime_put_sync(&pdev->dev);
	pm_runtime_disable(&pdev->dev);

	mfd_remove_devices(tscadc->dev);

	return 0;
	}

	#ifdef CONFIG_PM
	static int tscadc_suspend(struct device *dev)
	{
	struct ti_tscadc_dev *tscadc_dev = dev_get_drvdata(dev);

	tscadc_writel(tscadc_dev, REG_SE, 0x00);
	pm_runtime_put_sync(dev);

	return 0;
	}

	static int tscadc_resume(struct device *dev)
	{
	struct ti_tscadc_dev *tscadc_dev = dev_get_drvdata(dev);
	unsigned int restore, ctrl;

	pm_runtime_get_sync(dev);

	/* context restore */
	ctrl = CNTRLREG_STEPCONFIGWRT \| CNTRLREG_TSCENB \|
	CNTRLREG_STEPID \| CNTRLREG_4WIRE;
	tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
	tscadc_idle_config(tscadc_dev);
	am335x_tsc_se_update(tscadc_dev);
	restore = tscadc_readl(tscadc_dev, REG_CTRL);
	tscadc_writel(tscadc_dev, REG_CTRL,
	(restore \| CNTRLREG_TSCSSENB));

	return 0;
	}

	static const struct dev_pm_ops tscadc_pm_ops = {
	.suspend = tscadc_suspend,
	.resume = tscadc_resume,
	};
	#define TSCADC_PM_OPS (&tscadc_pm_ops)
	#else
	#define TSCADC_PM_OPS NULL
	#endif

	static const struct of_device_id ti_tscadc_dt_ids[] = {
	{ .compatible = "ti,am3359-tscadc", },
	{ }
	};
	MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids);

	static struct platform_driver ti_tscadc_driver = {
	.driver = {
	.name = "ti_am3359-tscadc",
	.owner = THIS_MODULE,
	.pm = TSCADC_PM_OPS,
	.of_match_table = of_match_ptr(ti_tscadc_dt_ids),
	},
	.probe = ti_tscadc_probe,
	.remove = ti_tscadc_remove,

	};

	module_platform_driver(ti_tscadc_driver);

	MODULE_DESCRIPTION("TI touchscreen / ADC MFD controller driver");
	MODULE_AUTHOR("Rachna Patil <[email protected]>");
	MODULE_LICENSE("GPL");