Re: [PATCH v2 15/19] media: imx: Add MIPI CSI-2 Receiver subdev driver

From: Steve Longerbeam
Date: Fri Jan 06 2017 - 13:58:36 EST




On 01/04/2017 07:05 AM, Vladimir Zapolskiy wrote:
On 01/03/2017 10:57 PM, Steve Longerbeam wrote:
Adds MIPI CSI-2 Receiver subdev driver. This subdev is required
for sensors with a MIPI CSI2 interface.

Signed-off-by: Steve Longerbeam <steve_longerbeam@xxxxxxxxxx>
---
drivers/staging/media/imx/Makefile | 1 +
drivers/staging/media/imx/imx-mipi-csi2.c | 509 ++++++++++++++++++++++++++++++
2 files changed, 510 insertions(+)
create mode 100644 drivers/staging/media/imx/imx-mipi-csi2.c

diff --git a/drivers/staging/media/imx/Makefile b/drivers/staging/media/imx/Makefile
index fe9e992..0decef7 100644
--- a/drivers/staging/media/imx/Makefile
+++ b/drivers/staging/media/imx/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_VIDEO_IMX_MEDIA) += imx-ic.o
obj-$(CONFIG_VIDEO_IMX_CAMERA) += imx-csi.o
obj-$(CONFIG_VIDEO_IMX_CAMERA) += imx-smfc.o
obj-$(CONFIG_VIDEO_IMX_CAMERA) += imx-camif.o
+obj-$(CONFIG_VIDEO_IMX_CAMERA) += imx-mipi-csi2.o
diff --git a/drivers/staging/media/imx/imx-mipi-csi2.c b/drivers/staging/media/imx/imx-mipi-csi2.c
new file mode 100644
index 0000000..84df16e
--- /dev/null
+++ b/drivers/staging/media/imx/imx-mipi-csi2.c
@@ -0,0 +1,509 @@
+/*
+ * MIPI CSI-2 Receiver Subdev for Freescale i.MX5/6 SOC.
+ *
+ * Copyright (c) 2012-2014 Mentor Graphics Inc.
+ *
+ * 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.
+ */
+#include <linux/module.h>
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/list.h>
+#include <linux/irq.h>
+#include <linux/of_device.h>
+#include <media/v4l2-device.h>
+#include <media/v4l2-of.h>
+#include <media/v4l2-subdev.h>
+#include <media/v4l2-async.h>
Please sort the list of headers alphabetically.

done.


+#include <asm/mach/irq.h>
Why do you need to include this header?

good question. In fact this include list was in need of a lot of pruning,
so I paired it down to the essentials.

+static int imxcsi2_s_stream(struct v4l2_subdev *sd, int enable)
+{
+ struct imxcsi2_dev *csi2 = sd_to_dev(sd);
+ int i, ret = 0;
+
+ if (!csi2->src_sd)
+ return -EPIPE;
+ for (i = 0; i < CSI2_NUM_SRC_PADS; i++) {
+ if (csi2->sink_sd[i])
+ break;
+ }
+ if (i >= CSI2_NUM_SRC_PADS)
+ return -EPIPE;
+
+ v4l2_info(sd, "stream %s\n", enable ? "ON" : "OFF");
+
+ if (enable && !csi2->stream_on) {
+ clk_prepare_enable(csi2->pix_clk);
It can complicate the design for you, but in general clk_prepare_enable()
can return an error.

I added an error check and reorganized a little.

+
+static int imxcsi2_parse_endpoints(struct imxcsi2_dev *csi2)
+{
+ struct device_node *node = csi2->dev->of_node;
+ struct device_node *epnode;
+ struct v4l2_of_endpoint ep;
+ int ret = 0;
+
+ epnode = of_graph_get_next_endpoint(node, NULL);
+ if (!epnode) {
+ v4l2_err(&csi2->sd, "failed to get endpoint node\n");
+ return -EINVAL;
+ }
+
+ v4l2_of_parse_endpoint(epnode, &ep);
Do of_node_put(epnode) here and remove 'out' goto label.

done.

+static const struct of_device_id imxcsi2_dt_ids[] = {
+ { .compatible = "fsl,imx-mipi-csi2", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imxcsi2_dt_ids);
+
+static struct platform_driver imxcsi2_driver = {
+ .driver = {
+ .name = DEVICE_NAME,
+ .owner = THIS_MODULE,
Please drop .owner assignment.

done.


Steve