]> pilppa.com Git - linux-2.6-omap-h63xx.git/commitdiff
[ARM] S3C24XX: ADC driver core
authorBen Dooks <ben-linux@fluff.org>
Thu, 18 Dec 2008 14:20:04 +0000 (14:20 +0000)
committerBen Dooks <ben-linux@fluff.org>
Thu, 18 Dec 2008 14:20:04 +0000 (14:20 +0000)
A common core driver for the S3C24XX ADC block so that
the touchscreen, hwmon and any other drivers can share
the resource.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
arch/arm/plat-s3c/include/plat/adc.h [new file with mode: 0644]
arch/arm/plat-s3c24xx/Kconfig
arch/arm/plat-s3c24xx/Makefile
arch/arm/plat-s3c24xx/adc.c [new file with mode: 0644]
arch/arm/plat-s3c24xx/devs.c

diff --git a/arch/arm/plat-s3c/include/plat/adc.h b/arch/arm/plat-s3c/include/plat/adc.h
new file mode 100644 (file)
index 0000000..43df2a4
--- /dev/null
@@ -0,0 +1,29 @@
+/* arch/arm/plat-s3c/include/plat/adc.h
+ *
+ * Copyright (c) 2008 Simtec Electronics
+ *     http://armlinux.simnte.co.uk/
+ *     Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C24XX ADC driver information
+ *
+ * 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.
+*/
+
+#ifndef __ASM_PLAT_ADC_H
+#define __ASM_PLAT_ADC_H __FILE__
+
+struct s3c_adc_client;
+
+extern int s3c_adc_start(struct s3c_adc_client *client,
+                        unsigned int channel, unsigned int nr_samples);
+
+extern struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
+                                              void (*select)(unsigned selected),
+                                              void (*conv)(unsigned d0, unsigned d1),
+                                              unsigned int is_ts);
+
+extern void s3c_adc_release(struct s3c_adc_client *client);
+
+#endif /* __ASM_PLAT_ADC_H */
index d3faf01bbfc2b9f5d3dc1745edf1eb17a8abd444..7d3d6eb5205ecce2739fb8256110b441c01cfbe2 100644 (file)
@@ -62,6 +62,13 @@ config S3C2410_DMA_DEBUG
          Enable debugging output for the DMA code. This option sends info
          to the kernel log, at priority KERN_DEBUG.
 
+config S3C24XX_ADC
+       bool "ADC common driver support"
+       help
+         Core support for the ADC block found in the S3C24XX SoC systems
+         for drivers such as the touchscreen and hwmon to use to share
+         this resource.
+
 # SPI default pin configuration code
 
 config S3C24XX_SPI_BUS0_GPE11_GPE12_GPE13
index 2a65ba7eb34d28fe3f587957cb6355ab9d092cf5..a8cfdefc29e9101b3a2ad67e44f34c191d1cf956 100644 (file)
@@ -31,6 +31,7 @@ obj-$(CONFIG_PM)              += sleep.o
 obj-$(CONFIG_HAVE_PWM)         += pwm.o
 obj-$(CONFIG_S3C2410_CLOCK)    += s3c2410-clock.o
 obj-$(CONFIG_S3C2410_DMA)      += dma.o
+obj-$(CONFIG_S3C24XX_ADC)      += adc.o
 
 # SPI gpio central GPIO functions
 
diff --git a/arch/arm/plat-s3c24xx/adc.c b/arch/arm/plat-s3c24xx/adc.c
new file mode 100644 (file)
index 0000000..9a5c767
--- /dev/null
@@ -0,0 +1,372 @@
+/* arch/arm/plat-s3c24xx/adc.c
+ *
+ * Copyright (c) 2008 Simtec Electronics
+ *     http://armlinux.simtec.co.uk/
+ *     Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org>
+ *
+ * S3C24XX 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/list.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/io.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.
+ */
+
+struct s3c_adc_client {
+       struct platform_device  *pdev;
+       struct list_head         pend;
+
+       unsigned int             nr_samples;
+       unsigned char            is_ts;
+       unsigned char            channel;
+
+       void    (*select_cb)(unsigned selected);
+       void    (*convert_cb)(unsigned val1, unsigned val2);
+};
+
+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;
+
+       unsigned int             prescale;
+
+       int                      irq;
+};
+
+static struct adc_device *adc_dev;
+
+static LIST_HEAD(adc_pending);
+
+#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);
+
+       client->select_cb(1);
+
+       con &= ~S3C2410_ADCCON_MUXMASK;
+       con &= ~S3C2410_ADCCON_STDBM;
+       con &= ~S3C2410_ADCCON_STARTMASK;
+
+       if (!client->is_ts)
+               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));
+}
+
+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;
+       }
+
+       if (client->is_ts && adc->ts_pend)
+               return -EAGAIN;
+
+       local_irq_save(flags);
+
+       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);
+       local_irq_restore(flags);
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(s3c_adc_start);
+
+static void s3c_adc_default_select(unsigned select)
+{
+}
+
+struct s3c_adc_client *s3c_adc_register(struct platform_device *pdev,
+                                       void (*select)(unsigned int selected),
+                                       void (*conv)(unsigned d0, unsigned d1),
+                                       unsigned int is_ts)
+{
+       struct s3c_adc_client *client;
+
+       WARN_ON(!pdev);
+       WARN_ON(!conv);
+
+       if (!select)
+               select = s3c_adc_default_select;
+
+       if (!conv || !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)
+{
+       /* We should really check that nothing is in progress. */
+       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;
+       unsigned long flags;
+       unsigned data0, data1;
+
+       if (!client) {
+               dev_warn(&adc->pdev->dev, "%s: no adc pending\n", __func__);
+               return IRQ_HANDLED;
+       }
+
+       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->convert_cb)(data0 & 0x3ff, data1 & 0x3ff);
+
+       if (--client->nr_samples > 0) {
+               /* fire another conversion for this */
+
+               client->select_cb(1);
+               s3c_adc_convert(adc);
+       } else {
+               local_irq_save(flags);
+               (client->select_cb)(0);
+               adc->cur = NULL;
+
+               s3c_adc_try(adc);
+               local_irq_restore(flags);
+       }
+
+       return IRQ_HANDLED;
+}
+
+static int s3c_adc_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct adc_device *adc;
+       struct resource *regs;
+       int ret;
+
+       adc = kzalloc(sizeof(struct adc_device), GFP_KERNEL);
+       if (adc == NULL) {
+               dev_err(dev, "failed to allocate adc_device\n");
+               return -ENOMEM;
+       }
+
+       adc->pdev = pdev;
+       adc->prescale = S3C2410_ADCCON_PRSCVL(49);
+
+       adc->irq = platform_get_irq(pdev, 1);
+       if (adc->irq <= 0) {
+               dev_err(dev, "failed to get adc irq\n");
+               ret = -ENOENT;
+               goto err_alloc;
+       }
+
+       ret = request_irq(adc->irq, s3c_adc_irq, 0, dev_name(dev), adc);
+       if (ret < 0) {
+               dev_err(dev, "failed to attach adc irq\n");
+               goto err_alloc;
+       }
+
+       adc->clk = clk_get(dev, "adc");
+       if (IS_ERR(adc->clk)) {
+               dev_err(dev, "failed to get adc clock\n");
+               ret = PTR_ERR(adc->clk);
+               goto err_irq;
+       }
+
+       regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!regs) {
+               dev_err(dev, "failed to find registers\n");
+               ret = -ENXIO;
+               goto err_clk;
+       }
+
+       adc->regs = ioremap(regs->start, resource_size(regs));
+       if (!adc->regs) {
+               dev_err(dev, "failed to map registers\n");
+               ret = -ENXIO;
+               goto err_clk;
+       }
+
+       clk_enable(adc->clk);
+
+       writel(adc->prescale | S3C2410_ADCCON_PRSCEN,
+              adc->regs + S3C2410_ADCCON);
+
+       dev_info(dev, "attached adc driver\n");
+
+       platform_set_drvdata(pdev, adc);
+       adc_dev = adc;
+
+       return 0;
+
+ err_clk:
+       clk_put(adc->clk);
+
+ err_irq:
+       free_irq(adc->irq, adc);
+
+ err_alloc:
+       kfree(adc);
+       return ret;
+}
+
+static int s3c_adc_remove(struct platform_device *pdev)
+{
+       struct adc_device *adc = platform_get_drvdata(pdev);
+
+       iounmap(adc->regs);
+       free_irq(adc->irq, adc);
+       clk_disable(adc->clk);
+       clk_put(adc->clk);
+       kfree(adc);
+
+       return 0;
+}
+
+#ifdef CONFIG_PM
+static int s3c_adc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+       struct adc_device *adc = platform_get_drvdata(pdev);
+       u32 con;
+
+       con = readl(adc->regs + S3C2410_ADCCON);
+       con |= S3C2410_ADCCON_STDBM;
+       writel(con, adc->regs + S3C2410_ADCCON);
+
+       clk_disable(adc->clk);
+
+       return 0;
+}
+
+static int s3c_adc_resume(struct platform_device *pdev)
+{
+       struct adc_device *adc = platform_get_drvdata(pdev);
+
+       clk_enable(adc->clk);
+
+       writel(adc->prescale | S3C2410_ADCCON_PRSCEN,
+              adc->regs + S3C2410_ADCCON);
+
+       return 0;
+}
+
+#else
+#define s3c_adc_suspend NULL
+#define s3c_adc_resume NULL
+#endif
+
+static struct platform_driver s3c_adc_driver = {
+       .driver         = {
+               .name   = "s3c24xx-adc",
+               .owner  = THIS_MODULE,
+       },
+       .probe          = s3c_adc_probe,
+       .remove         = __devexit_p(s3c_adc_remove),
+       .suspend        = s3c_adc_suspend,
+       .resume         = s3c_adc_resume,
+};
+
+static int __init adc_init(void)
+{
+       int ret;
+
+       ret = platform_driver_register(&s3c_adc_driver);
+       if (ret)
+               printk(KERN_ERR "%s: failed to add adc driver\n", __func__);
+
+       return ret;
+}
+
+arch_initcall(adc_init);
index adf535aaf43a20b00342ad139eb58529f609d6b7..6a33dbc494f44a15c18437a72c1d39eeeb090c6d 100644 (file)
@@ -372,12 +372,20 @@ static struct resource s3c_adc_resource[] = {
 };
 
 struct platform_device s3c_device_adc = {
-       .name             = "s3c2410-adc",
+       .name             = "s3c24xx-adc",
        .id               = -1,
        .num_resources    = ARRAY_SIZE(s3c_adc_resource),
        .resource         = s3c_adc_resource,
 };
 
+/* HWMON */
+
+struct platform_device s3c_device_hwmon = {
+       .name           = "s3c24xx-hwmon",
+       .id             = -1,
+       .dev.parent     = &s3c_device_adc.dev,
+};
+
 /* SDI */
 
 static struct resource s3c_sdi_resource[] = {