1 files changed, 323 insertions, 0 deletions
diff --git a/drivers/char/adc-s3c2443.c b/drivers/char/adc-s3c2443.c
new file mode 100644
index 000000000000..34de79e20045
--- /dev/null
+++ b/drivers/char/adc-s3c2443.c
@@ -0,0 +1,323 @@
+/*
+ * linux/drivers/char/adc-s3c2443.c
+ *
+ * Copyright (C) 2009 by Digi International Inc.
+ * 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 as published by
+ * the Free Software Foundation.
+ */
+/*
+ * In future, this driver should be replaced by the general adc core support 
+ * for the Samsung platforms, plus the corresponding hwmon driver and the touch
+ * driver that uses that common adc support.
+ */
+
+/*
+ * TODO, split from this driver and from the touch driver the common stuff and
+ * move it to a core adc module.
+ */
+
+
+#include <linux/cdev.h>
+#include <linux/clk.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/uaccess.h>
+#include <linux/delay.h>
+
+#include <plat/regs-adc.h>
+#include <plat/ts.h>
+
+#define DRIVER_NAME	"s3c2443-adc"
+#ifndef NUM_CHANNELS
+# define NUM_CHANNELS	10
+#endif
+
+struct s3c2443_adc_channel {
+	struct semaphore	sem;
+};
+
+struct s3c2443_adc_dev {
+	void __iomem			*ioaddr;
+	struct resource			*res_iomem;
+	struct clk			*clk;
+	struct cdev			cdev;
+	struct s3c2443_adc_channel	channel[NUM_CHANNELS];
+	dev_t				dev_id;
+	spinlock_t			lock;
+	u32				adccon;
+	u32				adctsc;
+  	u32				adcdly;
+};
+
+static struct s3c2443_adc_dev *adc;
+
+static u16 adc_read_sample(struct s3c2443_adc_dev *adcdev, int channel)
+{
+	u32 adccon, timeout = 5000;
+
+	/* Select channel, start conversion and wait until its completed */
+	writel(channel, adcdev->ioaddr + S3C2410_ADCMUX);
+	adccon = readl(adcdev->ioaddr + S3C2410_ADCCON);
+	writel(adccon | S3C2410_ADCCON_ENABLE_START, adcdev->ioaddr + S3C2410_ADCCON);
+	
+	while (timeout--) {
+		adccon = readl(adcdev->ioaddr + S3C2410_ADCCON);
+		if (adccon & S3C2410_ADCCON_ECFLG)
+			break;
+		ndelay(100);
+	}
+
+	return readl(adcdev->ioaddr + S3C2410_ADCDAT0) & S3C2410_ADCDAT0_XPDATA_MASK;
+}
+
+
+static ssize_t s3c2443_adc_read(struct file *filep, char __user *buff,
+				size_t count, loff_t *offp)
+{
+	struct s3c2443_adc_dev *adcdev = (struct s3c2443_adc_dev *)filep->private_data;
+	int ch = iminor(filep->f_dentry->d_inode);
+	u16 val12;
+	u8 val8;
+
+	val12 = adc_read_sample(adcdev, ch);
+	val8 = val12 >> 4;
+
+	count = (count > 2) ? 2 : count;
+	
+	if (count == 1)
+		copy_to_user(buff, &val8, count);
+	else
+		copy_to_user(buff, &val12, count);
+
+	return count;
+}
+
+static int s3c2443_adc_open(struct inode *inode, struct file *filep)
+{
+	struct s3c2443_adc_dev *adcdev = container_of(inode->i_cdev,
+						      struct s3c2443_adc_dev, cdev);
+	int ch = iminor(inode);
+
+	if (ch >= NUM_CHANNELS)
+		return -EINVAL;
+
+	if (down_trylock(&adcdev->channel[ch].sem) < 0)
+		return -EBUSY;
+
+	filep->private_data = (void *)adcdev;
+
+	return 0;
+}
+
+static int s3c2443_adc_release(struct inode *inode, struct file *filep)
+{
+	struct s3c2443_adc_dev *adcdev = container_of(inode->i_cdev,
+						      struct s3c2443_adc_dev, cdev);
+	int ch = iminor(inode);
+
+	up(&adcdev->channel[ch].sem);
+
+	return 0;
+}
+
+struct file_operations s3c2443_adc_fops = {
+	.owner		= THIS_MODULE,
+	.read		= s3c2443_adc_read,
+	.open		= s3c2443_adc_open,
+	.release	= s3c2443_adc_release,
+};
+
+static int __devinit s3c2443_adc_probe(struct platform_device *pdev)
+{
+	int ret, i;
+	struct s3c_ts_mach_info *info;
+
+	info = pdev->dev.platform_data;
+	if (!info) {
+		pr_err(DRIVER_NAME ": no platform data provided\n");
+		return -EINVAL;
+	}
+
+	adc = kzalloc(sizeof(*adc), GFP_KERNEL);
+	if (!adc) {
+		pr_err(DRIVER_NAME ": mem alloc error\n");
+		return -ENOMEM;
+	}
+
+	adc->res_iomem = platform_get_resource_byname(pdev, IORESOURCE_MEM, DRIVER_NAME);
+	if (!adc->res_iomem) {
+		pr_err(DRIVER_NAME ": unable to find iomem resource\n");
+		ret = -ENOENT;
+		goto error_get_res; 
+	}
+	/* 
+	 * Dont request mem region becasue the address space is shared with the touch
+         * driver. This will be resolved in future when both drivers use the same core
+	 * adc funcionality 
+	 */
+	adc->ioaddr = ioremap(adc->res_iomem->start, 
+			      adc->res_iomem->end - adc->res_iomem->start + 1);
+	if (!adc->ioaddr) {
+		pr_err(DRIVER_NAME ": unable to remap IO memory\n");
+		ret = -EBUSY;
+		goto error_remap;
+	}
+	pr_debug(DRIVER_NAME ": mapped ADC to virtual address 0x%x\n", (u32)adc->ioaddr);
+
+	ret = alloc_chrdev_region(&adc->dev_id, 0, NUM_CHANNELS, DRIVER_NAME);
+	if (ret < 0) {
+		pr_err(DRIVER_NAME ": error requesting chrdev_region for %d\n", adc->dev_id);
+		goto error_cdev_reg;
+	}
+
+	/* Get the required source clock */
+	adc->clk = clk_get(&pdev->dev, "adc");
+	if (IS_ERR(adc->clk)) {
+		pr_err(DRIVER_NAME ": error getting adc clock source\n");
+		ret = PTR_ERR(adc->clk);
+		goto error_get_clk;
+	}
+	clk_enable(adc->clk);
+	
+	/* initialize mutexes for every channel */
+	for (i = 0; i < NUM_CHANNELS; i++)
+		init_MUTEX(&adc->channel[i].sem);
+
+	cdev_init(&adc->cdev, &s3c2443_adc_fops);
+	ret = cdev_add(&adc->cdev, adc->dev_id, NUM_CHANNELS);
+	if (ret < 0) {
+		pr_err(DRIVER_NAME ": cannot add character device\n");
+ 		goto error_cdev_add;
+	}
+
+	/* Prepare the passed user configuration values */
+	if ((info->presc & 0xff) > 0)
+		writel(S3C2410_ADCCON_PRSCEN |
+		       S3C2410_ADCCON_PRSCVL(info->presc & 0xFF),
+		       adc->ioaddr + S3C2410_ADCCON);
+	else
+		writel(0, adc->ioaddr + S3C2410_ADCCON);
+
+
+	/* Initialise the start delay register (Manual: Do not use zero value) */
+	if ((info->delay & 0xffff) > 0)
+		writel(info->delay & 0xffff, adc->ioaddr + S3C2410_ADCDLY);
+	else
+		writel(10000,  adc->ioaddr + S3C2410_ADCDLY);
+
+	platform_set_drvdata(pdev, adc);
+
+	pr_info(DRIVER_NAME ": ADC available on MAJOR %i\n", MAJOR(adc->dev_id));
+
+	return 0;
+
+error_cdev_add:
+	clk_put(adc->clk);
+error_get_clk:
+	unregister_chrdev_region(adc->dev_id, NUM_CHANNELS);
+error_cdev_reg:
+	iounmap(adc->ioaddr);
+error_remap:
+error_get_res:
+	kfree(adc);
+	return ret;
+}
+
+int s3c2443_adc_remove(struct platform_device *pdev)
+{
+	int i;
+
+	if (!adc)
+		return -EIO;
+  
+	/* lock/check all channels */
+	for (i = 0; i < NUM_CHANNELS; i++) {
+		if (down_trylock(&adc->channel[i].sem))
+			/* channel still locked! */
+			goto adc_remove_unlock;
+	}
+
+	cdev_del(&adc->cdev);
+	clk_disable(adc->clk);
+	clk_put(adc->clk);
+ 	unregister_chrdev_region(adc->dev_id, NUM_CHANNELS);
+	iounmap(adc->ioaddr);
+	kfree(adc);
+	platform_set_drvdata(pdev, NULL);
+      
+	return 0;
+
+adc_remove_unlock:
+	for (i--; i >= 0; i--)
+		up(&adc->channel[i].sem);
+	return -EBUSY;
+}
+
+#ifdef CONFIG_PM
+static int s3c2443_adc_suspend(struct platform_device *dev, pm_message_t state)
+{
+	struct s3c2443_adc_dev *adc;
+
+	adc = platform_get_drvdata(dev);
+
+	/* save registers and disable the clock */
+	adc->adccon = readl(adc->ioaddr + S3C2410_ADCCON);
+	adc->adctsc = readl(adc->ioaddr + S3C2410_ADCTSC);
+	adc->adcdly = readl(adc->ioaddr + S3C2410_ADCDLY);
+	clk_disable(adc->clk);
+
+	return 0;
+}
+
+static int s3c2443_adc_resume(struct platform_device *pdev)
+{
+	struct s3c2443_adc_dev *adc;
+
+	adc = platform_get_drvdata(pdev);
+
+	/* restore registers and enable the clock */
+	clk_enable(adc->clk);
+	writel(adc->adccon, adc->ioaddr + S3C2410_ADCCON);
+	writel(adc->adctsc, adc->ioaddr + S3C2410_ADCTSC);
+	writel(adc->adcdly, adc->ioaddr + S3C2410_ADCDLY);
+		
+	return 0;
+}
+#else
+#define s3c2443_adc_suspend	NULL
+#define s3c2443_adc_resume	NULL
+#endif
+
+static struct platform_driver s3c2443_adc_driver = {
+	.probe		= s3c2443_adc_probe,
+	.remove		= __devexit_p(s3c2443_adc_remove),
+	.suspend	= s3c2443_adc_suspend,
+	.resume		= s3c2443_adc_resume,
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init s3c2443_adc_init(void)
+{
+	return platform_driver_register(&s3c2443_adc_driver);
+}
+
+static void __exit s3c2443_adc_exit(void)
+{
+	platform_driver_unregister(&s3c2443_adc_driver);
+}
+
+module_init(s3c2443_adc_init);
+module_exit(s3c2443_adc_exit);
+
+MODULE_AUTHOR("Digi International");
+MODULE_DESCRIPTION("ADC driver for S3C2443");
+MODULE_LICENSE("GPL v2");