HWMON: Add JZ4740 ADC driver

Add support for reading the ADCIN pin of the ADC unit on JZ4740 SoCs.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: lm-sensors@lm-sensors.org
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1425/
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

3 files changed, 241 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index e19cf8eb6ccf..c57e530d07c7 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -446,6 +446,16 @@ config SENSORS_IT87
           This driver can also be built as a module.  If so, the module
           will be called it87.
 
+config SENSORS_JZ4740
+        tristate "Ingenic JZ4740 SoC ADC driver"
+        depends on MACH_JZ4740 && MFD_JZ4740_ADC
+        help
+          If you say yes here you get support for reading adc values from the ADCIN
+          pin on Ingenic JZ4740 SoC based boards.
+
+          This driver can also be build as a module. If so, the module will be
+          called jz4740-hwmon.
+
 config SENSORS_LM63
         tristate "National Semiconductor LM63 and LM64"
         depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 2138ceb1a713..c5057745b068 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -55,6 +55,7 @@ obj-$(CONFIG_SENSORS_I5K_AMB)	+= i5k_amb.o
 obj-$(CONFIG_SENSORS_IBMAEM)    += ibmaem.o
 obj-$(CONFIG_SENSORS_IBMPEX)    += ibmpex.o
 obj-$(CONFIG_SENSORS_IT87)      += it87.o
+obj-$(CONFIG_SENSORS_JZ4740)    += jz4740-hwmon.o
 obj-$(CONFIG_SENSORS_K8TEMP)    += k8temp.o
 obj-$(CONFIG_SENSORS_K10TEMP)   += k10temp.o
 obj-$(CONFIG_SENSORS_LIS3LV02D) += lis3lv02d.o hp_accel.o
diff --git a/drivers/hwmon/jz4740-hwmon.c b/drivers/hwmon/jz4740-hwmon.c
new file mode 100644
index 000000000000..1c8b3d9e2051
--- /dev/null
+++ b/drivers/hwmon/jz4740-hwmon.c
@@ -0,0 +1,230 @@
+/*
+ * Copyright (C) 2009-2010, Lars-Peter Clausen <lars@metafoo.de>
+ * JZ4740 SoC HWMON driver
+ *
+ * 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, or (at your
+ * option) any later version.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <linux/completion.h>
+#include <linux/mfd/core.h>
+
+#include <linux/hwmon.h>
+
+struct jz4740_hwmon {
+        struct resource *mem;
+        void __iomem *base;
+
+        int irq;
+
+        struct mfd_cell *cell;
+        struct device *hwmon;
+
+        struct completion read_completion;
+
+        struct mutex lock;
+};
+
+static ssize_t jz4740_hwmon_show_name(struct device *dev,
+        struct device_attribute *dev_attr, char *buf)
+{
+        return sprintf(buf, "jz4740\n");
+}
+
+static irqreturn_t jz4740_hwmon_irq(int irq, void *data)
+{
+        struct jz4740_hwmon *hwmon = data;
+
+        complete(&hwmon->read_completion);
+        return IRQ_HANDLED;
+}
+
+static ssize_t jz4740_hwmon_read_adcin(struct device *dev,
+        struct device_attribute *dev_attr, char *buf)
+{
+        struct jz4740_hwmon *hwmon = dev_get_drvdata(dev);
+        struct completion *completion = &hwmon->read_completion;
+        unsigned long t;
+        unsigned long val;
+        int ret;
+
+        mutex_lock(&hwmon->lock);
+
+        INIT_COMPLETION(*completion);
+
+        enable_irq(hwmon->irq);
+        hwmon->cell->enable(to_platform_device(dev));
+
+        t = wait_for_completion_interruptible_timeout(completion, HZ);
+
+        if (t > 0) {
+                val = readw(hwmon->base) & 0xfff;
+                val = (val * 3300) >> 12;
+                ret = sprintf(buf, "%lu\n", val);
+        } else {
+                ret = t ? t : -ETIMEDOUT;
+        }
+
+        hwmon->cell->disable(to_platform_device(dev));
+        disable_irq(hwmon->irq);
+
+        mutex_unlock(&hwmon->lock);
+
+        return ret;
+}
+
+static DEVICE_ATTR(name, S_IRUGO, jz4740_hwmon_show_name, NULL);
+static DEVICE_ATTR(in0_input, S_IRUGO, jz4740_hwmon_read_adcin, NULL);
+
+static struct attribute *jz4740_hwmon_attributes[] = {
+        &dev_attr_name.attr,
+        &dev_attr_in0_input.attr,
+        NULL
+};
+
+static const struct attribute_group jz4740_hwmon_attr_group = {
+        .attrs = jz4740_hwmon_attributes,
+};
+
+static int __devinit jz4740_hwmon_probe(struct platform_device *pdev)
+{
+        int ret;
+        struct jz4740_hwmon *hwmon;
+
+        hwmon = kmalloc(sizeof(*hwmon), GFP_KERNEL);
+        if (!hwmon) {
+                dev_err(&pdev->dev, "Failed to allocate driver structure\n");
+                return -ENOMEM;
+        }
+
+        hwmon->cell = pdev->dev.platform_data;
+
+        hwmon->irq = platform_get_irq(pdev, 0);
+        if (hwmon->irq < 0) {
+                ret = hwmon->irq;
+                dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
+                goto err_free;
+        }
+
+        hwmon->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!hwmon->mem) {
+                ret = -ENOENT;
+                dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
+                goto err_free;
+        }
+
+        hwmon->mem = request_mem_region(hwmon->mem->start,
+                        resource_size(hwmon->mem), pdev->name);
+        if (!hwmon->mem) {
+                ret = -EBUSY;
+                dev_err(&pdev->dev, "Failed to request mmio memory region\n");
+                goto err_free;
+        }
+
+        hwmon->base = ioremap_nocache(hwmon->mem->start,
+                        resource_size(hwmon->mem));
+        if (!hwmon->base) {
+                ret = -EBUSY;
+                dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
+                goto err_release_mem_region;
+        }
+
+        init_completion(&hwmon->read_completion);
+        mutex_init(&hwmon->lock);
+
+        platform_set_drvdata(pdev, hwmon);
+
+        ret = request_irq(hwmon->irq, jz4740_hwmon_irq, 0, pdev->name, hwmon);
+        if (ret) {
+                dev_err(&pdev->dev, "Failed to request irq: %d\n", ret);
+                goto err_iounmap;
+        }
+        disable_irq(hwmon->irq);
+
+        ret = sysfs_create_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
+        if (ret) {
+                dev_err(&pdev->dev, "Failed to create sysfs group: %d\n", ret);
+                goto err_free_irq;
+        }
+
+        hwmon->hwmon = hwmon_device_register(&pdev->dev);
+        if (IS_ERR(hwmon->hwmon)) {
+                ret = PTR_ERR(hwmon->hwmon);
+                goto err_remove_file;
+        }
+
+        return 0;
+
+err_remove_file:
+        sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
+err_free_irq:
+        free_irq(hwmon->irq, hwmon);
+err_iounmap:
+        platform_set_drvdata(pdev, NULL);
+        iounmap(hwmon->base);
+err_release_mem_region:
+        release_mem_region(hwmon->mem->start, resource_size(hwmon->mem));
+err_free:
+        kfree(hwmon);
+
+        return ret;
+}
+
+static int __devexit jz4740_hwmon_remove(struct platform_device *pdev)
+{
+        struct jz4740_hwmon *hwmon = platform_get_drvdata(pdev);
+
+        hwmon_device_unregister(hwmon->hwmon);
+        sysfs_remove_group(&pdev->dev.kobj, &jz4740_hwmon_attr_group);
+
+        free_irq(hwmon->irq, hwmon);
+
+        iounmap(hwmon->base);
+        release_mem_region(hwmon->mem->start, resource_size(hwmon->mem));
+
+        platform_set_drvdata(pdev, NULL);
+        kfree(hwmon);
+
+        return 0;
+}
+
+struct platform_driver jz4740_hwmon_driver = {
+        .probe  = jz4740_hwmon_probe,
+        .remove = __devexit_p(jz4740_hwmon_remove),
+        .driver = {
+                .name = "jz4740-hwmon",
+                .owner = THIS_MODULE,
+        },
+};
+
+static int __init jz4740_hwmon_init(void)
+{
+        return platform_driver_register(&jz4740_hwmon_driver);
+}
+module_init(jz4740_hwmon_init);
+
+static void __exit jz4740_hwmon_exit(void)
+{
+        platform_driver_unregister(&jz4740_hwmon_driver);
+}
+module_exit(jz4740_hwmon_exit);
+
+MODULE_DESCRIPTION("JZ4740 SoC HWMON driver");
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:jz4740-hwmon");