Re: [PATCH 1/6] media: mach-pxa: Register the camera sensor fixed-rate clock
From: Petr Cvek <petrcvekcz@gmail.com>
Date: 2021-01-05 16:38:32
Dne 04. 01. 21 v 17:57 Ezequiel Garcia napsal(a):
The pxa-camera capture driver currently registers a v4l2-clk clock, named "mclk", to represent the mt9m111 sensor clock. Register a proper fixed-rate clock using the generic clock framework, which will allow to remove the v4l2-clk clock in the pxa-camera driver in a follow-up commit.
BTW the mclk output to a sensor is actually a variable rate, divided from lcdclk (which can be changed too). PXA camera driver is using variable pcdev->mclk_divisor to generate the mclk from lcdclk. The rate change is done in pxa_camera_activate(): https://elixir.bootlin.com/linux/v5.11-rc2/source/drivers/media/platform/pxa_camera.c#L1136 __raw_writel(pcdev->mclk_divisor | cicr4, pcdev->base + CICR4); Would it be possible to register a correct clock type with possibility to change the divisor by the standard way? Petr
quoted hunk ↗ jump to hunk
Cc: Arnd Bergmann <arnd@arndb.de> Cc: Robert Jarzmik <robert.jarzmik@free.fr> Signed-off-by: Ezequiel Garcia <redacted> --- arch/arm/mach-pxa/devices.c | 8 ++++++++ 1 file changed, 8 insertions(+)diff --git a/arch/arm/mach-pxa/devices.c b/arch/arm/mach-pxa/devices.c index 524d6093e0c7..09b8495f3fd9 100644 --- a/arch/arm/mach-pxa/devices.c +++ b/arch/arm/mach-pxa/devices.c@@ -4,6 +4,7 @@ #include <linux/init.h> #include <linux/platform_device.h> #include <linux/clkdev.h> +#include <linux/clk-provider.h> #include <linux/dma-mapping.h> #include <linux/dmaengine.h> #include <linux/spi/pxa2xx_spi.h>@@ -634,6 +635,13 @@ static struct platform_device pxa27x_device_camera = { void __init pxa_set_camera_info(struct pxacamera_platform_data *info) { + struct clk *mclk; + + /* Register a fixed-rate clock for camera sensors. */ + mclk = clk_register_fixed_rate(NULL, "pxa_camera_clk", NULL, 0, + info->mclk_10khz * 10000); + if (!IS_ERR(mclk)) + clkdev_create(mclk, "mclk", NULL); pxa_register_device(&pxa27x_device_camera, info); }