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| /* arch/arm/plat-samsung/adc.c * * Copyright (c) 2008 Simtec Electronics *	http://armlinux.simtec.co.uk/ *	Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org> * * Samsung ADC device core * * 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.*/#include <linux/module.h>#include <linux/kernel.h>#include <linux/platform_device.h>#include <linux/sched.h>#include <linux/list.h>#include <linux/slab.h>#include <linux/err.h>#include <linux/clk.h>#include <linux/interrupt.h>#include <linux/io.h>#include <linux/regulator/consumer.h>#include <plat/regs-adc.h>#include <plat/adc.h>/* This driver is designed to control the usage of the ADC block between * the touchscreen and any other drivers that may need to use it, such as * the hwmon driver. * * Priority will be given to the touchscreen driver, but as this itself is * rate limited it should not starve other requests which are processed in * order that they are received. * * Each user registers to get a client block which uniquely identifies it * and stores information such as the necessary functions to callback when * action is required. */enum s3c_cpu_type {	TYPE_ADCV1, /* S3C24XX */	TYPE_ADCV11, /* S3C2443 */	TYPE_ADCV12, /* S3C2416, S3C2450 */	TYPE_ADCV2, /* S3C64XX, S5P64X0, S5PC100 */	TYPE_ADCV3, /* S5PV210, S5PC110, EXYNOS4210 */};struct s3c_adc_client {	struct platform_device	*pdev;	struct list_head	 pend;	wait_queue_head_t	*wait;	unsigned int		 nr_samples;	int			 result;	unsigned char		 is_ts;	unsigned char		 channel;	void	(*select_cb)(struct s3c_adc_client *c, unsigned selected);	void	(*convert_cb)(struct s3c_adc_client *c,			      unsigned val1, unsigned val2,			      unsigned *samples_left);};struct adc_device {	struct platform_device	*pdev;	struct platform_device	*owner;	struct clk		*clk;	struct s3c_adc_client	*cur;	struct s3c_adc_client	*ts_pend;	void __iomem		*regs;	spinlock_t		 lock;	unsigned int		 prescale;	int			 irq;	struct regulator	*vdd;};static struct adc_device *adc_dev;static LIST_HEAD(adc_pending);	/* protected by adc_device.lock */#define adc_dbg(_adc, msg...) dev_dbg(&(_adc)->pdev->dev, msg)static inline void s3c_adc_convert(struct adc_device *adc){	unsigned con = readl(adc->regs + S3C2410_ADCCON);	con |= S3C2410_ADCCON_ENABLE_START;	writel(con, adc->regs + S3C2410_ADCCON);}static inline void s3c_adc_select(struct adc_device *adc,				  struct s3c_adc_client *client){	unsigned con = readl(adc->regs + S3C2410_ADCCON);	enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;	client->select_cb(client, 1);	if (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV2)		con &= ~S3C2410_ADCCON_MUXMASK;	con &= ~S3C2410_ADCCON_STDBM;	con &= ~S3C2410_ADCCON_STARTMASK;	if (!client->is_ts) {		if (cpu == TYPE_ADCV3)			writel(client->channel & 0xf, adc->regs + S5P_ADCMUX);		else if (cpu == TYPE_ADCV11 || cpu == TYPE_ADCV12)			writel(client->channel & 0xf,						adc->regs + S3C2443_ADCMUX);		else			con |= S3C2410_ADCCON_SELMUX(client->channel);	}	writel(con, adc->regs + S3C2410_ADCCON);}static void s3c_adc_dbgshow(struct adc_device *adc){	adc_dbg(adc, "CON=%08x, TSC=%08x, DLY=%08x\n",		readl(adc->regs + S3C2410_ADCCON),		readl(adc->regs + S3C2410_ADCTSC),		readl(adc->regs + S3C2410_ADCDLY));}static void s3c_adc_try(struct adc_device *adc){	struct s3c_adc_client *next = adc->ts_pend;	if (!next && !list_empty(&adc_pending)) {		next = list_first_entry(&adc_pending,					struct s3c_adc_client, pend);		list_del(&next->pend);	} else		adc->ts_pend = NULL;	if (next) {		adc_dbg(adc, "new client is %p\n", next);		adc->cur = next;		s3c_adc_select(adc, next);		s3c_adc_convert(adc);		s3c_adc_dbgshow(adc);	}}int s3c_adc_start(struct s3c_adc_client *client,		  unsigned int channel, unsigned int nr_samples){	struct adc_device *adc = adc_dev;	unsigned long flags;	if (!adc) {		printk(KERN_ERR "%s: failed to find adc\n", __func__);		return -EINVAL;	}	spin_lock_irqsave(&adc->lock, flags);	if (client->is_ts && adc->ts_pend) {		spin_unlock_irqrestore(&adc->lock, flags);		return -EAGAIN;	}	client->channel = channel;	client->nr_samples = nr_samples;	if (client->is_ts)		adc->ts_pend = client;	else		list_add_tail(&client->pend, &adc_pending);	if (!adc->cur)		s3c_adc_try(adc);	spin_unlock_irqrestore(&adc->lock, flags);	return 0;}EXPORT_SYMBOL_GPL(s3c_adc_start);static void s3c_convert_done(struct s3c_adc_client *client,			     unsigned v, unsigned u, unsigned *left){	client->result = v;	wake_up(client->wait);}int s3c_adc_read(struct s3c_adc_client *client, unsigned int ch){	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wake);	int ret;	client->convert_cb = s3c_convert_done;	client->wait = &wake;	client->result = -1;	ret = s3c_adc_start(client, ch, 1);	if (ret < 0)		goto err;	ret = wait_event_timeout(wake, client->result >= 0, HZ / 2);	if (client->result < 0) {		ret = -ETIMEDOUT;		goto err;	}	client->convert_cb = NULL;	return client->result;err:	return ret;}EXPORT_SYMBOL_GPL(s3c_adc_read);static void s3c_adc_default_select(struct s3c_adc_client *client,				   unsigned select){}struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,					void (*select)(struct s3c_adc_client *client,						       unsigned int selected),					void (*conv)(struct s3c_adc_client *client,						     unsigned d0, unsigned d1,						     unsigned *samples_left),					unsigned int is_ts){	struct s3c_adc_client *client;	WARN_ON(!pdev);	if (!select)		select = s3c_adc_default_select;	if (!pdev)		return ERR_PTR(-EINVAL);	client = kzalloc(sizeof(struct s3c_adc_client), GFP_KERNEL);	if (!client) {		dev_err(&pdev->dev, "no memory for adc client\n");		return ERR_PTR(-ENOMEM);	}	client->pdev = pdev;	client->is_ts = is_ts;	client->select_cb = select;	client->convert_cb = conv;	return client;}EXPORT_SYMBOL_GPL(s3c_adc_register);void s3c_adc_release(struct s3c_adc_client *client){	unsigned long flags;	spin_lock_irqsave(&adc_dev->lock, flags);	/* We should really check that nothing is in progress. */	if (adc_dev->cur == client)		adc_dev->cur = NULL;	if (adc_dev->ts_pend == client)		adc_dev->ts_pend = NULL;	else {		struct list_head *p, *n;		struct s3c_adc_client *tmp;		list_for_each_safe(p, n, &adc_pending) {			tmp = list_entry(p, struct s3c_adc_client, pend);			if (tmp == client)				list_del(&tmp->pend);		}	}	if (adc_dev->cur == NULL)		s3c_adc_try(adc_dev);	spin_unlock_irqrestore(&adc_dev->lock, flags);	kfree(client);}EXPORT_SYMBOL_GPL(s3c_adc_release);static irqreturn_t s3c_adc_irq(int irq, void *pw){	struct adc_device *adc = pw;	struct s3c_adc_client *client = adc->cur;	enum s3c_cpu_type cpu = platform_get_device_id(adc->pdev)->driver_data;	unsigned data0, data1;	if (!client) {		dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);		goto exit;	}	data0 = readl(adc->regs + S3C2410_ADCDAT0);	data1 = readl(adc->regs + S3C2410_ADCDAT1);	adc_dbg(adc, "read %d: 0x%04x, 0x%04x\n", client->nr_samples, data0, data1);	client->nr_samples--;	if (cpu == TYPE_ADCV1 || cpu == TYPE_ADCV11) {		data0 &= 0x3ff;		data1 &= 0x3ff;	} else {		/* S3C2416/S3C64XX/S5P ADC resolution is 12-bit */		data0 &= 0xfff;		data1 &= 0xfff;	}	if (client->convert_cb)		(client->convert_cb)(client, data0, data1, &client->nr_samples);	if (client->nr_samples > 0) {		/* fire another conversion for this */		client->select_cb(client, 1);		s3c_adc_convert(adc);	} else {		spin_lock(&adc->lock);		(client->select_cb)(client, 0);		adc->cur = NULL;		s3c_adc_try(adc);		spin_unlock(&adc->lock);	}exit:	if (cpu == TYPE_ADCV2 || cpu == TYPE_ADCV3) {		/* Clear ADC interrupt */		writel(0, adc->regs + S3C64XX_ADCCLRINT);	}	return IRQ_HANDLED;}static int s3c_adc_probe(struct platform_device *pdev){	struct device *dev = &pdev->dev;	struct adc_device *adc;	struct resource *regs;	enum s3c_cpu_type cpu = platform_get_device_id(pdev)->driver_data;	int ret;	unsigned tmp;	adc = devm_kzalloc(dev, sizeof(struct adc_device), GFP_KERNEL);	if (adc == NULL) {		dev_err(dev, "failed to allocate adc_device\n");		return -ENOMEM;	}	spin_lock_init(&adc->lock);	adc->pdev = pdev;	adc->prescale = S3C2410_ADCCON_PRSCVL(49);	adc->vdd = devm_regulator_get(dev, "vdd");	if (IS_ERR(adc->vdd)) {		dev_err(dev, "operating without regulator \"vdd\" .\n");		return PTR_ERR(adc->vdd);	}	adc->irq = platform_get_irq(pdev, 1);	if (adc->irq <= 0) {		dev_err(dev, "failed to get adc irq\n");		return -ENOENT;	}	ret = devm_request_irq(dev, adc->irq, s3c_adc_irq, 0, dev_name(dev),				adc);	if (ret < 0) {		dev_err(dev, "failed to attach adc irq\n");		return ret;	}	adc->clk = devm_clk_get(dev, "adc");	if (IS_ERR(adc->clk)) {		dev_err(dev, "failed to get adc clock\n");		return PTR_ERR(adc->clk);	}	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);	if (!regs) {		dev_err(dev, "failed to find registers\n");		return -ENXIO;	}	adc->regs = devm_request_and_ioremap(dev, regs);	if (!adc->regs) {		dev_err(dev, "failed to map registers\n");		return -ENXIO;	}	ret = regulator_enable(adc->vdd);	if (ret)		return ret;	clk_enable(adc->clk);	tmp = adc->prescale | S3C2410_ADCCON_PRSCEN;	/* Enable 12-bit ADC resolution */
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