media: marvell-ccic: provide a clock for the sensor

The sensor needs the MCLK clock running when it's being probed. On
platforms where the sensor is instantiated from a DT (MMP2) it is going
to happen asynchronously.

Therefore, the current modus operandi, where the bridge driver fiddles
with the sensor power and clock itself is not going to fly. As the comments
wisely note, this doesn't even belong there.

Luckily, the ov7670 driver is already able to control its power and
reset lines, we can just drop the MMP platform glue altogether.

It also requests the clock via the standard clock subsystem. Good -- let's
set up a clock instance so that the sensor can ask us to enable the clock.
Note that this is pretty dumb at the moment: the clock is hardwired to a
particular frequency and parent. It was always the case.

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 130 insertions, 42 deletions

diff --git a/drivers/media/platform/marvell-ccic/mcam-core.c b/drivers/media/platform/marvell-ccic/mcam-core.c
index 7dc7d9d91782..f9ac1547d093 100644
--- a/drivers/media/platform/marvell-ccic/mcam-core.c
+++ b/drivers/media/platform/marvell-ccic/mcam-core.c
@@ -22,6 +22,7 @@
 #include <linux/vmalloc.h>
 #include <linux/io.h>
 #include <linux/clk.h>
+#include <linux/clk-provider.h>
 #include <linux/videodev2.h>
 #include <media/v4l2-device.h>
 #include <media/v4l2-ioctl.h>
@@ -303,9 +304,6 @@ static void mcam_enable_mipi(struct mcam_camera *mcam)
 		 */
 		mcam_reg_write(mcam, REG_CSI2_CTRL0,
 			CSI2_C0_MIPI_EN | CSI2_C0_ACT_LANE(mcam->lane));
-		mcam_reg_write(mcam, REG_CLKCTRL,
-			(mcam->mclk_src << 29) | mcam->mclk_div);
-
 		mcam->mipi_enabled = true;
 	}
 }
@@ -830,31 +828,6 @@ static void mcam_ctlr_irq_disable(struct mcam_camera *cam)
 	mcam_reg_clear_bit(cam, REG_IRQMASK, FRAMEIRQS);
 }
 
-
-
-static void mcam_ctlr_init(struct mcam_camera *cam)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&cam->dev_lock, flags);
-	/*
-	 * Make sure it's not powered down.
-	 */
-	mcam_reg_clear_bit(cam, REG_CTRL1, C1_PWRDWN);
-	/*
-	 * Turn off the enable bit.  It sure should be off anyway,
-	 * but it's good to be sure.
-	 */
-	mcam_reg_clear_bit(cam, REG_CTRL0, C0_ENABLE);
-	/*
-	 * Clock the sensor appropriately.  Controller clock should
-	 * be 48MHz, sensor "typical" value is half that.
-	 */
-	mcam_reg_write_mask(cam, REG_CLKCTRL, 2, CLK_DIV_MASK);
-	spin_unlock_irqrestore(&cam->dev_lock, flags);
-}
-
-
 /*
  * Stop the controller, and don't return until we're really sure that no
  * further DMA is going on.
@@ -898,14 +871,15 @@ static int mcam_ctlr_power_up(struct mcam_camera *cam)
 	int ret;
 
 	spin_lock_irqsave(&cam->dev_lock, flags);
-	ret = cam->plat_power_up(cam);
-	if (ret) {
-		spin_unlock_irqrestore(&cam->dev_lock, flags);
-		return ret;
+	if (cam->plat_power_up) {
+		ret = cam->plat_power_up(cam);
+		if (ret) {
+			spin_unlock_irqrestore(&cam->dev_lock, flags);
+			return ret;
+		}
 	}
 	mcam_reg_clear_bit(cam, REG_CTRL1, C1_PWRDWN);
 	spin_unlock_irqrestore(&cam->dev_lock, flags);
-	msleep(5); /* Just to be sure */
 	return 0;
 }
 
@@ -920,10 +894,101 @@ static void mcam_ctlr_power_down(struct mcam_camera *cam)
 	 * power down routine.
 	 */
 	mcam_reg_set_bit(cam, REG_CTRL1, C1_PWRDWN);
-	cam->plat_power_down(cam);
+	if (cam->plat_power_down)
+		cam->plat_power_down(cam);
 	spin_unlock_irqrestore(&cam->dev_lock, flags);
 }
 
+/* ---------------------------------------------------------------------- */
+/*
+ * Controller clocks.
+ */
+static void mcam_clk_enable(struct mcam_camera *mcam)
+{
+	unsigned int i;
+
+	for (i = 0; i < NR_MCAM_CLK; i++) {
+		if (!IS_ERR(mcam->clk[i]))
+			clk_prepare_enable(mcam->clk[i]);
+	}
+}
+
+static void mcam_clk_disable(struct mcam_camera *mcam)
+{
+	int i;
+
+	for (i = NR_MCAM_CLK - 1; i >= 0; i--) {
+		if (!IS_ERR(mcam->clk[i]))
+			clk_disable_unprepare(mcam->clk[i]);
+	}
+}
+
+/* ---------------------------------------------------------------------- */
+/*
+ * Master sensor clock.
+ */
+static int mclk_prepare(struct clk_hw *hw)
+{
+	struct mcam_camera *cam = container_of(hw, struct mcam_camera, mclk_hw);
+
+	clk_prepare(cam->clk[0]);
+	return 0;
+}
+
+static void mclk_unprepare(struct clk_hw *hw)
+{
+	struct mcam_camera *cam = container_of(hw, struct mcam_camera, mclk_hw);
+
+	clk_unprepare(cam->clk[0]);
+}
+
+static int mclk_enable(struct clk_hw *hw)
+{
+	struct mcam_camera *cam = container_of(hw, struct mcam_camera, mclk_hw);
+	int mclk_src;
+	int mclk_div;
+
+	/*
+	 * Clock the sensor appropriately.  Controller clock should
+	 * be 48MHz, sensor "typical" value is half that.
+	 */
+	if (cam->bus_type == V4L2_MBUS_CSI2_DPHY) {
+		mclk_src = cam->mclk_src;
+		mclk_div = cam->mclk_div;
+	} else {
+		mclk_src = 3;
+		mclk_div = 2;
+	}
+
+	clk_enable(cam->clk[0]);
+	mcam_reg_write(cam, REG_CLKCTRL, (mclk_src << 29) | mclk_div);
+	mcam_ctlr_power_up(cam);
+
+	return 0;
+}
+
+static void mclk_disable(struct clk_hw *hw)
+{
+	struct mcam_camera *cam = container_of(hw, struct mcam_camera, mclk_hw);
+
+	mcam_ctlr_power_down(cam);
+	clk_disable(cam->clk[0]);
+}
+
+static unsigned long mclk_recalc_rate(struct clk_hw *hw,
+				unsigned long parent_rate)
+{
+	return 48000000;
+}
+
+static const struct clk_ops mclk_ops = {
+	.prepare = mclk_prepare,
+	.unprepare = mclk_unprepare,
+	.enable = mclk_enable,
+	.disable = mclk_disable,
+	.recalc_rate = mclk_recalc_rate,
+};
+
 /* -------------------------------------------------------------------- */
 /*
  * Communications with the sensor.
@@ -948,7 +1013,6 @@ static int mcam_cam_init(struct mcam_camera *cam)
 	ret = __mcam_cam_reset(cam);
 	/* Get/set parameters? */
 	cam->state = S_IDLE;
-	mcam_ctlr_power_down(cam);
 	return ret;
 }
 
@@ -1584,9 +1648,10 @@ static int mcam_v4l_open(struct file *filp)
 	if (ret)
 		goto out;
 	if (v4l2_fh_is_singular_file(filp)) {
-		ret = mcam_ctlr_power_up(cam);
+		ret = sensor_call(cam, core, s_power, 1);
 		if (ret)
 			goto out;
+		mcam_clk_enable(cam);
 		__mcam_cam_reset(cam);
 		mcam_set_config_needed(cam, 1);
 	}
@@ -1608,7 +1673,8 @@ static int mcam_v4l_release(struct file *filp)
 	_vb2_fop_release(filp, NULL);
 	if (last_open) {
 		mcam_disable_mipi(cam);
-		mcam_ctlr_power_down(cam);
+		sensor_call(cam, core, s_power, 0);
+		mcam_clk_disable(cam);
 		if (cam->buffer_mode == B_vmalloc && alloc_bufs_at_read)
 			mcam_free_dma_bufs(cam);
 	}
@@ -1806,6 +1872,7 @@ static const struct v4l2_async_notifier_operations mccic_notify_ops = {
 
 int mccic_register(struct mcam_camera *cam)
 {
+	struct clk_init_data mclk_init = { };
 	int ret;
 
 	/*
@@ -1838,7 +1905,6 @@ int mccic_register(struct mcam_camera *cam)
 	mcam_set_config_needed(cam, 1);
 	cam->pix_format = mcam_def_pix_format;
 	cam->mbus_code = mcam_def_mbus_code;
-	mcam_ctlr_init(cam);
 
 	/*
 	 * Register sensor notifier.
@@ -1858,6 +1924,26 @@ int mccic_register(struct mcam_camera *cam)
 	}
 
 	/*
+	 * Register sensor master clock.
+	 */
+	mclk_init.parent_names = NULL;
+	mclk_init.num_parents = 0;
+	mclk_init.ops = &mclk_ops;
+	mclk_init.name = "mclk";
+
+	of_property_read_string(cam->dev->of_node, "clock-output-names",
+							&mclk_init.name);
+
+	cam->mclk_hw.init = &mclk_init;
+
+	cam->mclk = devm_clk_register(cam->dev, &cam->mclk_hw);
+	if (IS_ERR(cam->mclk)) {
+		ret = PTR_ERR(cam->mclk);
+		dev_err(cam->dev, "can't register clock\n");
+		goto out;
+	}
+
+	/*
 	 * If so requested, try to get our DMA buffers now.
 	 */
 	if (cam->buffer_mode == B_vmalloc && !alloc_bufs_at_read) {
@@ -1884,7 +1970,7 @@ void mccic_shutdown(struct mcam_camera *cam)
 	 */
 	if (!list_empty(&cam->vdev.fh_list)) {
 		cam_warn(cam, "Removing a device with users!\n");
-		mcam_ctlr_power_down(cam);
+		sensor_call(cam, core, s_power, 0);
 	}
 	if (cam->buffer_mode == B_vmalloc)
 		mcam_free_dma_bufs(cam);
@@ -1906,7 +1992,8 @@ void mccic_suspend(struct mcam_camera *cam)
 		enum mcam_state cstate = cam->state;
 
 		mcam_ctlr_stop_dma(cam);
-		mcam_ctlr_power_down(cam);
+		sensor_call(cam, core, s_power, 0);
+		mcam_clk_disable(cam);
 		cam->state = cstate;
 	}
 	mutex_unlock(&cam->s_mutex);
@@ -1919,14 +2006,15 @@ int mccic_resume(struct mcam_camera *cam)
 
 	mutex_lock(&cam->s_mutex);
 	if (!list_empty(&cam->vdev.fh_list)) {
-		ret = mcam_ctlr_power_up(cam);
+		mcam_clk_enable(cam);
+		ret = sensor_call(cam, core, s_power, 1);
 		if (ret) {
 			mutex_unlock(&cam->s_mutex);
 			return ret;
 		}
 		__mcam_cam_reset(cam);
 	} else {
-		mcam_ctlr_power_down(cam);
+		sensor_call(cam, core, s_power, 0);
 	}
 	mutex_unlock(&cam->s_mutex);