V4L/DVB: V4L2: sh_mobile_camera_ceu: add support for CSI2

Using CEU with CSI2 on SH-Mobile requires some special configuration of the
former. We also have to switch from calling only one subdev .s_mbus_fmt and
.try_mbus_fmt to calling all subdevices. Take care to increment CSI2 driver
use count to prevent it from unloading, while in use.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

2 files changed, 119 insertions, 15 deletions

diff --git a/drivers/media/video/sh_mobile_ceu_camera.c b/drivers/media/video/sh_mobile_ceu_camera.c
index 86869dbcbab0..2b24bd0de3ad 100644
--- a/drivers/media/video/sh_mobile_ceu_camera.c
+++ b/drivers/media/video/sh_mobile_ceu_camera.c
@@ -633,6 +633,12 @@ static void sh_mobile_ceu_set_rect(struct soc_camera_device *icd)
                 cdwdr_width *= 2;
         }
 
+        /* CSI2 special configuration */
+        if (pcdev->pdata->csi2_dev) {
+                in_width = ((in_width - 2) * 2);
+                left_offset *= 2;
+        }
+
         /* Set CAMOR, CAPWR, CFSZR, take care of CDWDR */
         camor = left_offset | (top_offset << 16);
 
@@ -767,6 +773,11 @@ static int sh_mobile_ceu_set_bus_param(struct soc_camera_device *icd,
         value |= common_flags & SOCAM_VSYNC_ACTIVE_LOW ? 1 << 1 : 0;
         value |= common_flags & SOCAM_HSYNC_ACTIVE_LOW ? 1 << 0 : 0;
         value |= pcdev->is_16bit ? 1 << 12 : 0;
+
+        /* CSI2 mode */
+        if (pcdev->pdata->csi2_dev)
+                value |= 3 << 12;
+
         ceu_write(pcdev, CAMCR, value);
 
         ceu_write(pcdev, CAPCR, 0x00300000);
@@ -883,6 +894,8 @@ static int sh_mobile_ceu_get_formats(struct soc_camera_device *icd, unsigned int
 {
         struct v4l2_subdev *sd = soc_camera_to_subdev(icd);
         struct device *dev = icd->dev.parent;
+        struct soc_camera_host *ici = to_soc_camera_host(dev);
+        struct sh_mobile_ceu_dev *pcdev = ici->priv;
         int ret, k, n;
         int formats = 0;
         struct sh_mobile_ceu_cam *cam;
@@ -896,19 +909,19 @@ static int sh_mobile_ceu_get_formats(struct soc_camera_device *icd, unsigned int
 
         fmt = soc_mbus_get_fmtdesc(code);
         if (!fmt) {
-                dev_err(icd->dev.parent,
-                        "Invalid format code #%u: %d\n", idx, code);
+                dev_err(dev, "Invalid format code #%u: %d\n", idx, code);
                 return -EINVAL;
         }
 
-        ret = sh_mobile_ceu_try_bus_param(icd, fmt->bits_per_sample);
-        if (ret < 0)
-                return 0;
+        if (!pcdev->pdata->csi2_dev) {
+                ret = sh_mobile_ceu_try_bus_param(icd, fmt->bits_per_sample);
+                if (ret < 0)
+                        return 0;
+        }
 
         if (!icd->host_priv) {
                 struct v4l2_mbus_framefmt mf;
                 struct v4l2_rect rect;
-                struct device *dev = icd->dev.parent;
                 int shift = 0;
 
                 /* FIXME: subwindow is lost between close / open */
@@ -927,7 +940,8 @@ static int sh_mobile_ceu_get_formats(struct soc_camera_device *icd, unsigned int
                         /* Try 2560x1920, 1280x960, 640x480, 320x240 */
                         mf.width        = 2560 >> shift;
                         mf.height       = 1920 >> shift;
-                        ret = v4l2_subdev_call(sd, video, s_mbus_fmt, &mf);
+                        ret = v4l2_device_call_until_err(sd->v4l2_dev, 0, video,
+                                                         s_mbus_fmt, &mf);
                         if (ret < 0)
                                 return ret;
                         shift++;
@@ -1228,7 +1242,8 @@ static int client_s_fmt(struct soc_camera_device *icd,
         struct v4l2_cropcap cap;
         int ret;
 
-        ret = v4l2_subdev_call(sd, video, s_mbus_fmt, mf);
+        ret = v4l2_device_call_until_err(sd->v4l2_dev, 0, video,
+                                         s_mbus_fmt, mf);
         if (ret < 0)
                 return ret;
 
@@ -1257,7 +1272,8 @@ static int client_s_fmt(struct soc_camera_device *icd,
                 tmp_h = min(2 * tmp_h, max_height);
                 mf->width = tmp_w;
                 mf->height = tmp_h;
-                ret = v4l2_subdev_call(sd, video, s_mbus_fmt, mf);
+                ret = v4l2_device_call_until_err(sd->v4l2_dev, 0, video,
+                                                 s_mbus_fmt, mf);
                 dev_geo(dev, "Camera scaled to %ux%u\n",
                         mf->width, mf->height);
                 if (ret < 0) {
@@ -1514,7 +1530,8 @@ static int sh_mobile_ceu_set_fmt(struct soc_camera_device *icd,
         struct device *dev = icd->dev.parent;
         __u32 pixfmt = pix->pixelformat;
         const struct soc_camera_format_xlate *xlate;
-        unsigned int ceu_sub_width, ceu_sub_height;
+        /* Keep Compiler Happy */
+        unsigned int ceu_sub_width = 0, ceu_sub_height = 0;
         u16 scale_v, scale_h;
         int ret;
         bool image_mode;
@@ -1569,8 +1586,8 @@ static int sh_mobile_ceu_set_fmt(struct soc_camera_device *icd,
 
         /* Done with the camera. Now see if we can improve the result */
 
-        dev_geo(dev, "Camera %d fmt %ux%u, requested %ux%u\n",
-                ret, mf.width, mf.height, pix->width, pix->height);
+        dev_geo(dev, "fmt %ux%u, requested %ux%u\n",
+                mf.width, mf.height, pix->width, pix->height);
         if (ret < 0)
                 return ret;
 
@@ -1634,6 +1651,9 @@ static int sh_mobile_ceu_try_fmt(struct soc_camera_device *icd,
         int width, height;
         int ret;
 
+        dev_geo(icd->dev.parent, "TRY_FMT(pix=0x%x, %ux%u)\n",
+                 pixfmt, pix->width, pix->height);
+
         xlate = soc_camera_xlate_by_fourcc(icd, pixfmt);
         if (!xlate) {
                 dev_warn(icd->dev.parent, "Format %x not found\n", pixfmt);
@@ -1660,7 +1680,7 @@ static int sh_mobile_ceu_try_fmt(struct soc_camera_device *icd,
         mf.code         = xlate->code;
         mf.colorspace   = pix->colorspace;
 
-        ret = v4l2_subdev_call(sd, video, try_mbus_fmt, &mf);
+        ret = v4l2_device_call_until_err(sd->v4l2_dev, 0, video, try_mbus_fmt, &mf);
         if (ret < 0)
                 return ret;
 
@@ -1684,7 +1704,8 @@ static int sh_mobile_ceu_try_fmt(struct soc_camera_device *icd,
                          */
                         mf.width = 2560;
                         mf.height = 1920;
-                        ret = v4l2_subdev_call(sd, video, try_mbus_fmt, &mf);
+                        ret = v4l2_device_call_until_err(sd->v4l2_dev, 0, video,
+                                                         try_mbus_fmt, &mf);
                         if (ret < 0) {
                                 /* Shouldn't actually happen... */
                                 dev_err(icd->dev.parent,
@@ -1699,6 +1720,9 @@ static int sh_mobile_ceu_try_fmt(struct soc_camera_device *icd,
                         pix->height = height;
         }
 
+        dev_geo(icd->dev.parent, "%s(): return %d, fmt 0x%x, %ux%u\n",
+                __func__, ret, pix->pixelformat, pix->width, pix->height);
+
         return ret;
 }
 
@@ -1853,6 +1877,30 @@ static struct soc_camera_host_ops sh_mobile_ceu_host_ops = {
         .num_controls   = ARRAY_SIZE(sh_mobile_ceu_controls),
 };
 
+struct bus_wait {
+        struct notifier_block   notifier;
+        struct completion       completion;
+        struct device           *dev;
+};
+
+static int bus_notify(struct notifier_block *nb,
+                      unsigned long action, void *data)
+{
+        struct device *dev = data;
+        struct bus_wait *wait = container_of(nb, struct bus_wait, notifier);
+
+        if (wait->dev != dev)
+                return NOTIFY_DONE;
+
+        switch (action) {
+        case BUS_NOTIFY_UNBOUND_DRIVER:
+                /* Protect from module unloading */
+                wait_for_completion(&wait->completion);
+                return NOTIFY_OK;
+        }
+        return NOTIFY_DONE;
+}
+
 static int __devinit sh_mobile_ceu_probe(struct platform_device *pdev)
 {
         struct sh_mobile_ceu_dev *pcdev;
@@ -1860,6 +1908,11 @@ static int __devinit sh_mobile_ceu_probe(struct platform_device *pdev)
         void __iomem *base;
         unsigned int irq;
         int err = 0;
+        struct bus_wait wait = {
+                .completion = COMPLETION_INITIALIZER_ONSTACK(wait.completion),
+                .notifier.notifier_call = bus_notify,
+        };
+        struct device *csi2;
 
         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
         irq = platform_get_irq(pdev, 0);
@@ -1931,12 +1984,54 @@ static int __devinit sh_mobile_ceu_probe(struct platform_device *pdev)
         pcdev->ici.drv_name = dev_name(&pdev->dev);
         pcdev->ici.ops = &sh_mobile_ceu_host_ops;
 
+        /* CSI2 interfacing */
+        csi2 = pcdev->pdata->csi2_dev;
+        if (csi2) {
+                wait.dev = csi2;
+
+                err = bus_register_notifier(&platform_bus_type, &wait.notifier);
+                if (err < 0)
+                        goto exit_free_clk;
+
+                /*
+                 * From this point the driver module will not unload, until
+                 * we complete the completion.
+                 */
+
+                if (!csi2->driver || !csi2->driver->owner) {
+                        complete(&wait.completion);
+                        /* Either too late, or probing failed */
+                        bus_unregister_notifier(&platform_bus_type, &wait.notifier);
+                        err = -ENXIO;
+                        goto exit_free_clk;
+                }
+
+                /*
+                 * The module is still loaded, in the worst case it is hanging
+                 * in device release on our completion. So, _now_ dereferencing
+                 * the "owner" is safe!
+                 */
+
+                err = try_module_get(csi2->driver->owner);
+
+                /* Let notifier complete, if it has been locked */
+                complete(&wait.completion);
+                bus_unregister_notifier(&platform_bus_type, &wait.notifier);
+                if (!err) {
+                        err = -ENODEV;
+                        goto exit_free_clk;
+                }
+        }
+
         err = soc_camera_host_register(&pcdev->ici);
         if (err)
-                goto exit_free_clk;
+                goto exit_module_put;
 
         return 0;
 
+exit_module_put:
+        if (csi2 && csi2->driver)
+                module_put(csi2->driver->owner);
 exit_free_clk:
         pm_runtime_disable(&pdev->dev);
         free_irq(pcdev->irq, pcdev);
@@ -1956,6 +2051,7 @@ static int __devexit sh_mobile_ceu_remove(struct platform_device *pdev)
         struct soc_camera_host *soc_host = to_soc_camera_host(&pdev->dev);
         struct sh_mobile_ceu_dev *pcdev = container_of(soc_host,
                                         struct sh_mobile_ceu_dev, ici);
+        struct device *csi2 = pcdev->pdata->csi2_dev;
 
         soc_camera_host_unregister(soc_host);
         pm_runtime_disable(&pdev->dev);
@@ -1963,7 +2059,10 @@ static int __devexit sh_mobile_ceu_remove(struct platform_device *pdev)
         if (platform_get_resource(pdev, IORESOURCE_MEM, 1))
                 dma_release_declared_memory(&pdev->dev);
         iounmap(pcdev->base);
+        if (csi2 && csi2->driver)
+                module_put(csi2->driver->owner);
         kfree(pcdev);
+
         return 0;
 }
 
@@ -1995,6 +2094,8 @@ static struct platform_driver sh_mobile_ceu_driver = {
 
 static int __init sh_mobile_ceu_init(void)
 {
+        /* Whatever return code */
+        request_module("sh_mobile_csi2");
         return platform_driver_register(&sh_mobile_ceu_driver);
 }
 
diff --git a/include/media/sh_mobile_ceu.h b/include/media/sh_mobile_ceu.h
index b67747836878..80346a6d28a9 100644
--- a/include/media/sh_mobile_ceu.h
+++ b/include/media/sh_mobile_ceu.h
@@ -6,8 +6,11 @@
 #define SH_CEU_FLAG_HSYNC_LOW           (1 << 2) /* default High if possible */
 #define SH_CEU_FLAG_VSYNC_LOW           (1 << 3) /* default High if possible */
 
+struct device;
+
 struct sh_mobile_ceu_info {
         unsigned long flags;
+        struct device *csi2_dev;
 };
 
 #endif /* __ASM_SH_MOBILE_CEU_H__ */