[media] marvell-cam: Basic working MMP camera driver

Now we have a camera working over the marvell cam controller core. It
works like the cafe driver and has all the same limitations, contiguous DMA
only being one of them. But it's a start.

Signed-off-by: Jonathan Corbet <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/video/Makefile

···
 obj-$(CONFIG_VIDEO_CX2341X) += cx2341x.o
 
 obj-$(CONFIG_VIDEO_CAFE_CCIC) += marvell-ccic/
+obj-$(CONFIG_VIDEO_MMP_CAMERA) += marvell-ccic/
 
 obj-$(CONFIG_VIDEO_VIA_CAMERA) += via-camera.o
 

drivers/media/video/marvell-ccic/Kconfig

···
 	  CMOS camera controller.  This is the controller found on first-
 	  generation OLPC systems.
 
+config VIDEO_MMP_CAMERA
+	tristate "Marvell Armada 610 integrated camera controller support"
+	depends on ARCH_MMP && I2C && VIDEO_V4L2
+	select VIDEO_OV7670
+	select I2C_GPIO
+	---help---
+	  This is a Video4Linux2 driver for the integrated camera
+	  controller found on Marvell Armada 610 application
+	  processors (and likely beyond).  This is the controller found
+	  in OLPC XO 1.75 systems.
+

drivers/media/video/marvell-ccic/Makefile

···
 obj-$(CONFIG_VIDEO_CAFE_CCIC) += cafe_ccic.o
 cafe_ccic-y := cafe-driver.o mcam-core.o
+
+obj-$(CONFIG_VIDEO_MMP_CAMERA) += mmp_camera.o
+mmp_camera-y := mmp-driver.o mcam-core.o
+

drivers/media/video/marvell-ccic/mcam-core.c

···
 
 
 /*
- * Debugging and related.  FIXME these are broken
+ * Debugging and related.
  */
 #define cam_err(cam, fmt, arg...) \
 	dev_err((cam)->dev, fmt, ##arg);
···
 		mcam_reg_clear_bit(cam, REG_CTRL1, C1_TWOBUFS);
 	} else
 		mcam_reg_set_bit(cam, REG_CTRL1, C1_TWOBUFS);
-	mcam_reg_write(cam, REG_UBAR, 0); /* 32 bits only for now */
+	if (cam->chip_id == V4L2_IDENT_CAFE)
+		mcam_reg_write(cam, REG_UBAR, 0); /* 32 bits only */
 }
 
 static void mcam_ctlr_image(struct mcam_camera *cam)
···
 	unsigned long flags;
 
 	spin_lock_irqsave(&cam->dev_lock, flags);
-	mcam_reg_clear_bit(cam, REG_CTRL1, C1_PWRDWN);
 	cam->plat_power_up(cam);
+	mcam_reg_clear_bit(cam, REG_CTRL1, C1_PWRDWN);
 	spin_unlock_irqrestore(&cam->dev_lock, flags);
 	msleep(5); /* Just to be sure */
 }
···
 	unsigned long flags;
 
 	spin_lock_irqsave(&cam->dev_lock, flags);
-	cam->plat_power_down(cam);
+	/*
+	 * School of hard knocks department: be sure we do any register
+	 * twiddling on the controller *before* calling the platform
+	 * power down routine.
+	 */
 	mcam_reg_set_bit(cam, REG_CTRL1, C1_PWRDWN);
+	cam->plat_power_down(cam);
 	spin_unlock_irqrestore(&cam->dev_lock, flags);
 }
 
···
 
 void mccic_shutdown(struct mcam_camera *cam)
 {
-	if (cam->users > 0)
+	/*
+	 * If we have no users (and we really, really should have no
+	 * users) the device will already be powered down.  Trying to
+	 * take it down again will wedge the machine, which is frowned
+	 * upon.
+	 */
+	if (cam->users > 0) {
 		cam_warn(cam, "Removing a device with users!\n");
+		mcam_ctlr_power_down(cam);
+	}
+	mcam_free_dma_bufs(cam);
 	if (cam->n_sbufs > 0)
 		/* What if they are still mapped?  Shouldn't be, but... */
 		mcam_free_sio_buffers(cam);
-	mcam_ctlr_stop_dma(cam);
-	mcam_ctlr_power_down(cam);
-	mcam_free_dma_bufs(cam);
 	video_unregister_device(&cam->vdev);
 	v4l2_device_unregister(&cam->v4l2_dev);
 }

drivers/media/video/marvell-ccic/mmp-driver.c

···
+/*
+ * Support for the camera device found on Marvell MMP processors; known
+ * to work with the Armada 610 as used in the OLPC 1.75 system.
+ *
+ * Copyright 2011 Jonathan Corbet <[e-mail]>
+ *
+ * This file may be distributed under the terms of the GNU General
+ * Public License, version 2.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/i2c-gpio.h>
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/videodev2.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-chip-ident.h>
+#include <media/mmp-camera.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/list.h>
+
+#include "mcam-core.h"
+
+MODULE_AUTHOR("Jonathan Corbet <[e-mail]>");
+MODULE_LICENSE("GPL");
+
+struct mmp_camera {
+	void *power_regs;
+	struct platform_device *pdev;
+	struct mcam_camera mcam;
+	struct list_head devlist;
+	int irq;
+};
+
+static inline struct mmp_camera *mcam_to_cam(struct mcam_camera *mcam)
+{
+	return container_of(mcam, struct mmp_camera, mcam);
+}
+
+/*
+ * A silly little infrastructure so we can keep track of our devices.
+ * Chances are that we will never have more than one of them, but
+ * the Armada 610 *does* have two controllers...
+ */
+
+static LIST_HEAD(mmpcam_devices);
+static struct mutex mmpcam_devices_lock;
+
+static void mmpcam_add_device(struct mmp_camera *cam)
+{
+	mutex_lock(&mmpcam_devices_lock);
+	list_add(&cam->devlist, &mmpcam_devices);
+	mutex_unlock(&mmpcam_devices_lock);
+}
+
+static void mmpcam_remove_device(struct mmp_camera *cam)
+{
+	mutex_lock(&mmpcam_devices_lock);
+	list_del(&cam->devlist);
+	mutex_unlock(&mmpcam_devices_lock);
+}
+
+/*
+ * Platform dev remove passes us a platform_device, and there's
+ * no handy unused drvdata to stash a backpointer in.  So just
+ * dig it out of our list.
+ */
+static struct mmp_camera *mmpcam_find_device(struct platform_device *pdev)
+{
+	struct mmp_camera *cam;
+
+	mutex_lock(&mmpcam_devices_lock);
+	list_for_each_entry(cam, &mmpcam_devices, devlist) {
+		if (cam->pdev == pdev) {
+			mutex_unlock(&mmpcam_devices_lock);
+			return cam;
+		}
+	}
+	mutex_unlock(&mmpcam_devices_lock);
+	return NULL;
+}
+
+
+
+
+/*
+ * Power-related registers; this almost certainly belongs
+ * somewhere else.
+ *
+ * ARMADA 610 register manual, sec 7.2.1, p1842.
+ */
+#define CPU_SUBSYS_PMU_BASE	0xd4282800
+#define REG_CCIC_DCGCR		0x28	/* CCIC dyn clock gate ctrl reg */
+#define REG_CCIC_CRCR		0x50	/* CCIC clk reset ctrl reg	*/
+
+/*
+ * Power control.
+ */
+static void mmpcam_power_up(struct mcam_camera *mcam)
+{
+	struct mmp_camera *cam = mcam_to_cam(mcam);
+	struct mmp_camera_platform_data *pdata;
+/*
+ * Turn on power and clocks to the controller.
+ */
+	iowrite32(0x3f, cam->power_regs + REG_CCIC_DCGCR);
+	iowrite32(0x3805b, cam->power_regs + REG_CCIC_CRCR);
+	mdelay(1);
+/*
+ * Provide power to the sensor.
+ */
+	mcam_reg_write(mcam, REG_CLKCTRL, 0x60000002);
+	pdata = cam->pdev->dev.platform_data;
+	gpio_set_value(pdata->sensor_power_gpio, 1);
+	mdelay(5);
+	mcam_reg_clear_bit(mcam, REG_CTRL1, 0x10000000);
+	gpio_set_value(pdata->sensor_reset_gpio, 0); /* reset is active low */
+	mdelay(5);
+	gpio_set_value(pdata->sensor_reset_gpio, 1); /* reset is active low */
+	mdelay(5);
+}
+
+static void mmpcam_power_down(struct mcam_camera *mcam)
+{
+	struct mmp_camera *cam = mcam_to_cam(mcam);
+	struct mmp_camera_platform_data *pdata;
+/*
+ * Turn off clocks and set reset lines
+ */
+	iowrite32(0, cam->power_regs + REG_CCIC_DCGCR);
+	iowrite32(0, cam->power_regs + REG_CCIC_CRCR);
+/*
+ * Shut down the sensor.
+ */
+	pdata = cam->pdev->dev.platform_data;
+	gpio_set_value(pdata->sensor_power_gpio, 0);
+	gpio_set_value(pdata->sensor_reset_gpio, 0);
+}
+
+
+static irqreturn_t mmpcam_irq(int irq, void *data)
+{
+	struct mcam_camera *mcam = data;
+	unsigned int irqs, handled;
+
+	spin_lock(&mcam->dev_lock);
+	irqs = mcam_reg_read(mcam, REG_IRQSTAT);
+	handled = mccic_irq(mcam, irqs);
+	spin_unlock(&mcam->dev_lock);
+	return IRQ_RETVAL(handled);
+}
+
+
+static int mmpcam_probe(struct platform_device *pdev)
+{
+	struct mmp_camera *cam;
+	struct mcam_camera *mcam;
+	struct resource *res;
+	struct mmp_camera_platform_data *pdata;
+	int ret;
+
+	cam = kzalloc(sizeof(*cam), GFP_KERNEL);
+	if (cam == NULL)
+		return -ENOMEM;
+	cam->pdev = pdev;
+	INIT_LIST_HEAD(&cam->devlist);
+
+	mcam = &cam->mcam;
+	mcam->platform = MHP_Armada610;
+	mcam->plat_power_up = mmpcam_power_up;
+	mcam->plat_power_down = mmpcam_power_down;
+	mcam->dev = &pdev->dev;
+	mcam->use_smbus = 0;
+	mcam->chip_id = V4L2_IDENT_ARMADA610;
+	spin_lock_init(&mcam->dev_lock);
+	/*
+	 * Get our I/O memory.
+	 */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res == NULL) {
+		dev_err(&pdev->dev, "no iomem resource!\n");
+		ret = -ENODEV;
+		goto out_free;
+	}
+	mcam->regs = ioremap(res->start, resource_size(res));
+	if (mcam->regs == NULL) {
+		dev_err(&pdev->dev, "MMIO ioremap fail\n");
+		ret = -ENODEV;
+		goto out_free;
+	}
+	/*
+	 * Power/clock memory is elsewhere; get it too.  Perhaps this
+	 * should really be managed outside of this driver?
+	 */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (res == NULL) {
+		dev_err(&pdev->dev, "no power resource!\n");
+		ret = -ENODEV;
+		goto out_unmap1;
+	}
+	cam->power_regs = ioremap(res->start, resource_size(res));
+	if (cam->power_regs == NULL) {
+		dev_err(&pdev->dev, "power MMIO ioremap fail\n");
+		ret = -ENODEV;
+		goto out_unmap1;
+	}
+	/*
+	 * Find the i2c adapter.  This assumes, of course, that the
+	 * i2c bus is already up and functioning.
+	 */
+	pdata = pdev->dev.platform_data;
+	mcam->i2c_adapter = platform_get_drvdata(pdata->i2c_device);
+	if (mcam->i2c_adapter == NULL) {
+		ret = -ENODEV;
+		dev_err(&pdev->dev, "No i2c adapter\n");
+		goto out_unmap2;
+	}
+	/*
+	 * Sensor GPIO pins.
+	 */
+	ret = gpio_request(pdata->sensor_power_gpio, "cam-power");
+	if (ret) {
+		dev_err(&pdev->dev, "Can't get sensor power gpio %d",
+				pdata->sensor_power_gpio);
+		goto out_unmap2;
+	}
+	gpio_direction_output(pdata->sensor_power_gpio, 0);
+	ret = gpio_request(pdata->sensor_reset_gpio, "cam-reset");
+	if (ret) {
+		dev_err(&pdev->dev, "Can't get sensor reset gpio %d",
+				pdata->sensor_reset_gpio);
+		goto out_gpio;
+	}
+	gpio_direction_output(pdata->sensor_reset_gpio, 0);
+	/*
+	 * Power the device up and hand it off to the core.
+	 */
+	mmpcam_power_up(mcam);
+	ret = mccic_register(mcam);
+	if (ret)
+		goto out_gpio2;
+	/*
+	 * Finally, set up our IRQ now that the core is ready to
+	 * deal with it.
+	 */
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+	if (res == NULL) {
+		ret = -ENODEV;
+		goto out_unregister;
+	}
+	cam->irq = res->start;
+	ret = request_irq(cam->irq, mmpcam_irq, IRQF_SHARED,
+			"mmp-camera", mcam);
+	if (ret == 0) {
+		mmpcam_add_device(cam);
+		return 0;
+	}
+
+out_unregister:
+	mccic_shutdown(mcam);
+	mmpcam_power_down(mcam);
+out_gpio2:
+	gpio_free(pdata->sensor_reset_gpio);
+out_gpio:
+	gpio_free(pdata->sensor_power_gpio);
+out_unmap2:
+	iounmap(cam->power_regs);
+out_unmap1:
+	iounmap(mcam->regs);
+out_free:
+	kfree(cam);
+	return ret;
+}
+
+
+static int mmpcam_remove(struct mmp_camera *cam)
+{
+	struct mcam_camera *mcam = &cam->mcam;
+	struct mmp_camera_platform_data *pdata;
+
+	mmpcam_remove_device(cam);
+	free_irq(cam->irq, mcam);
+	mccic_shutdown(mcam);
+	mmpcam_power_down(mcam);
+	pdata = cam->pdev->dev.platform_data;
+	gpio_free(pdata->sensor_reset_gpio);
+	gpio_free(pdata->sensor_power_gpio);
+	iounmap(cam->power_regs);
+	iounmap(mcam->regs);
+	kfree(cam);
+	return 0;
+}
+
+static int mmpcam_platform_remove(struct platform_device *pdev)
+{
+	struct mmp_camera *cam = mmpcam_find_device(pdev);
+
+	if (cam == NULL)
+		return -ENODEV;
+	return mmpcam_remove(cam);
+}
+
+
+static struct platform_driver mmpcam_driver = {
+	.probe		= mmpcam_probe,
+	.remove		= mmpcam_platform_remove,
+	.driver = {
+		.name	= "mmp-camera",
+		.owner	= THIS_MODULE
+	}
+};
+
+
+static int __init mmpcam_init_module(void)
+{
+	mutex_init(&mmpcam_devices_lock);
+	return platform_driver_register(&mmpcam_driver);
+}
+
+static void __exit mmpcam_exit_module(void)
+{
+	platform_driver_unregister(&mmpcam_driver);
+	/*
+	 * platform_driver_unregister() should have emptied the list
+	 */
+	if (!list_empty(&mmpcam_devices))
+		printk(KERN_ERR "mmp_camera leaving devices behind\n");
+}
+
+module_init(mmpcam_init_module);
+module_exit(mmpcam_exit_module);

include/media/mmp-camera.h

···
+/*
+ * Information for the Marvell Armada MMP camera
+ */
+
+struct mmp_camera_platform_data {
+	struct platform_device *i2c_device;
+	int sensor_power_gpio;
+	int sensor_reset_gpio;
+};

include/media/v4l2-chip-ident.h

···
 	/* module wm8775: just ident 8775 */
 	V4L2_IDENT_WM8775 = 8775,
 
-	/* module cafe_ccic, just ident 8801 */
+	/* Marvell controllers starting at 8801 */
 	V4L2_IDENT_CAFE = 8801,
+	V4L2_IDENT_ARMADA610 = 8802,
 
 	/* AKM AK8813/AK8814 */
 	V4L2_IDENT_AK8813 = 8813,