From 09c1533f7f5dabd79aa2018083d1b71d26cd7eda Mon Sep 17 00:00:00 2001 From: Naushir Patuck Date: Mon, 11 May 2020 13:02:22 +0100 Subject: [PATCH] media: bcm2835: unicam: Set VPU min clock freq to 250Mhz. When streaming with Unicam, the VPU must have a clock frequency of at least 250Mhz. Otherwise, the input fifos could overrun, causing image corruption. Signed-off-by: Naushir Patuck --- arch/arm/boot/dts/bcm270x.dtsi | 10 ++-- .../media/platform/bcm2835/bcm2835-unicam.c | 49 +++++++++++++++++-- 2 files changed, 50 insertions(+), 9 deletions(-) --- a/arch/arm/boot/dts/bcm270x.dtsi +++ b/arch/arm/boot/dts/bcm270x.dtsi @@ -88,8 +88,9 @@ reg = <0x7e800000 0x800>, <0x7e802000 0x4>; interrupts = <2 6>; - clocks = <&clocks BCM2835_CLOCK_CAM0>; - clock-names = "lp"; + clocks = <&clocks BCM2835_CLOCK_CAM0>, + <&firmware_clocks 4>; + clock-names = "lp", "vpu"; power-domains = <&power RPI_POWER_DOMAIN_UNICAM0>; #address-cells = <1>; #size-cells = <0>; @@ -102,8 +103,9 @@ reg = <0x7e801000 0x800>, <0x7e802004 0x4>; interrupts = <2 7>; - clocks = <&clocks BCM2835_CLOCK_CAM1>; - clock-names = "lp"; + clocks = <&clocks BCM2835_CLOCK_CAM1>, + <&firmware_clocks 4>; + clock-names = "lp", "vpu"; power-domains = <&power RPI_POWER_DOMAIN_UNICAM1>; #address-cells = <1>; #size-cells = <0>; --- a/drivers/media/platform/bcm2835/bcm2835-unicam.c +++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c @@ -89,6 +89,11 @@ MODULE_PARM_DESC(debug, "Debug level 0-3 v4l2_err(&(dev)->v4l2_dev, fmt, ##arg) /* + * Unicam must request a minimum of 250Mhz from the VPU clock. + * Otherwise the input FIFOs overrun and cause image corruption. + */ +#define MIN_VPU_CLOCK_RATE (250 * 1000 * 1000) +/* * To protect against a dodgy sensor driver never returning an error from * enum_mbus_code, set a maximum index value to be used. */ @@ -417,8 +422,10 @@ struct unicam_device { void __iomem *base; /* clock gating base address */ void __iomem *clk_gate_base; - /* clock handle */ + /* lp clock handle */ struct clk *clock; + /* vpu clock handle */ + struct clk *vpu_clock; /* V4l2 device */ struct v4l2_device v4l2_dev; struct media_device mdev; @@ -1674,16 +1681,28 @@ static int unicam_start_streaming(struct unicam_dbg(1, dev, "Running with %u data lanes\n", dev->active_data_lanes); - ret = clk_set_rate(dev->clock, 100 * 1000 * 1000); + ret = clk_set_min_rate(dev->vpu_clock, MIN_VPU_CLOCK_RATE); + if (ret) { + unicam_err(dev, "failed to set up VPU clock\n"); + goto err_pm_put; + } + + ret = clk_prepare_enable(dev->vpu_clock); if (ret) { - unicam_err(dev, "failed to set up clock\n"); + unicam_err(dev, "Failed to enable VPU clock: %d\n", ret); goto err_pm_put; } + ret = clk_set_rate(dev->clock, 100 * 1000 * 1000); + if (ret) { + unicam_err(dev, "failed to set up CSI clock\n"); + goto err_vpu_clock; + } + ret = clk_prepare_enable(dev->clock); if (ret) { unicam_err(dev, "Failed to enable CSI clock: %d\n", ret); - goto err_pm_put; + goto err_vpu_clock; } for (i = 0; i < ARRAY_SIZE(dev->node); i++) { @@ -1717,6 +1736,11 @@ static int unicam_start_streaming(struct err_disable_unicam: unicam_disable(dev); clk_disable_unprepare(dev->clock); +err_vpu_clock: + ret = clk_set_min_rate(dev->vpu_clock, 0); + if (ret) + unicam_err(dev, "failed to reset the VPU clock\n"); + clk_disable_unprepare(dev->vpu_clock); err_pm_put: unicam_runtime_put(dev); err_streaming: @@ -1734,6 +1758,8 @@ static void unicam_stop_streaming(struct node->streaming = false; if (node->pad_id == IMAGE_PAD) { + int ret; + /* * Stop streaming the sensor and disable the peripheral. * We cannot continue streaming embedded data with the @@ -1743,6 +1769,12 @@ static void unicam_stop_streaming(struct unicam_err(dev, "stream off failed in subdev\n"); unicam_disable(dev); + + ret = clk_set_min_rate(dev->vpu_clock, 0); + if (ret) + unicam_err(dev, "failed to reset the min VPU clock\n"); + + clk_disable_unprepare(dev->vpu_clock); clk_disable_unprepare(dev->clock); unicam_runtime_put(dev); @@ -2742,11 +2774,18 @@ static int unicam_probe(struct platform_ unicam->clock = devm_clk_get(&pdev->dev, "lp"); if (IS_ERR(unicam->clock)) { - unicam_err(unicam, "Failed to get clock\n"); + unicam_err(unicam, "Failed to get lp clock\n"); ret = PTR_ERR(unicam->clock); goto err_unicam_put; } + unicam->vpu_clock = devm_clk_get(&pdev->dev, "vpu"); + if (IS_ERR(unicam->vpu_clock)) { + unicam_err(unicam, "Failed to get vpu clock\n"); + ret = PTR_ERR(unicam->vpu_clock); + goto err_unicam_put; + } + ret = platform_get_irq(pdev, 0); if (ret <= 0) { dev_err(&pdev->dev, "No IRQ resource\n");