[PATCH 6/6] clk: imx8mp: inform CCF of maximum frequency of clocks

Peng Fan peng.fan at oss.nxp.com
Thu Dec 19 22:18:05 PST 2024


On Thu, Dec 19, 2024 at 08:27:37AM +0100, Ahmad Fatoum wrote:
>The IMX8MPCEC datasheet lists maximum frequencies allowed for different
>modules. Some of these limits are universal, but some depend on
>whether the SoC is operating in nominal or in overdrive mode.
>
>The imx8mp.dtsi currently assumes overdrive mode and configures some
>clocks in accordance with this. Boards wishing to make use of nominal
>mode will need to override some of the clock rates manually.
>
>As operating the clocks outside of their allowed range can lead to
>difficult to debug issues, it makes sense to register the maximum rates
>allowed in the driver, so the CCF can take them into account.
>
>Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
>---
> drivers/clk/imx/clk-imx8mp.c | 147 +++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 147 insertions(+)
>
>diff --git a/drivers/clk/imx/clk-imx8mp.c b/drivers/clk/imx/clk-imx8mp.c
>index 516dbd170c8a..3b06990b73ad 100644
>--- a/drivers/clk/imx/clk-imx8mp.c
>+++ b/drivers/clk/imx/clk-imx8mp.c
>@@ -8,6 +8,7 @@
> #include <linux/err.h>
> #include <linux/io.h>
> #include <linux/module.h>
>+#include <linux/units.h>
> #include <linux/of_address.h>
> #include <linux/platform_device.h>
> #include <linux/slab.h>
>@@ -405,6 +406,145 @@ static const char * const imx8mp_clkout_sels[] = {"audio_pll1_out", "audio_pll2_
> static struct clk_hw **hws;
> static struct clk_hw_onecell_data *clk_hw_data;
> 
>+struct imx8mp_clock_constraints {
>+	int clkid;
>+	u32 maxrate;
>+};
>+
>+/*
>+ * Below tables are taken from IMX8MPCEC Rev. 2.1, 07/2023
>+ * Table 13. Maximum frequency of modules.
>+ * Probable typos fixed are marked with a comment.
>+ */
>+static const struct imx8mp_clock_constraints imx8mp_clock_common_constraints[] = {
>+	{ IMX8MP_CLK_A53_DIV,             1000 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_ENET_AXI,             266666667 }, /* Datasheet claims 266MHz */
>+	{ IMX8MP_CLK_NAND_USDHC_BUS,       266666667 }, /* Datasheet claims 266MHz */
>+	{ IMX8MP_CLK_MEDIA_APB,            200 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_HDMI_APB,             133333333 }, /* Datasheet claims 133MHz */
>+	{ IMX8MP_CLK_ML_AXI,               800 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_AHB,                  133333333 },
>+	{ IMX8MP_CLK_IPG_ROOT,              66666667 },
>+	{ IMX8MP_CLK_AUDIO_AHB,            400 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_MEDIA_DISP2_PIX,      170 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_DRAM_ALT,             666666667 },
>+	{ IMX8MP_CLK_DRAM_APB,             200 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_CAN1,                  80 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_CAN2,                  80 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_PCIE_AUX,              10 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_I2C5,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_I2C6,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_SAI1,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_SAI2,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_SAI3,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_SAI5,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_SAI6,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_ENET_QOS,             125 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_ENET_QOS_TIMER,       200 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_ENET_REF,             125 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_ENET_TIMER,           125 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_ENET_PHY_REF,         125 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_NAND,                 500 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_QSPI,                 400 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_USDHC1,               400 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_USDHC2,               400 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_I2C1,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_I2C2,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_I2C3,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_I2C4,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_UART1,                 80 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_UART2,                 80 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_UART3,                 80 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_UART4,                 80 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_ECSPI1,                80 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_ECSPI2,                80 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_PWM1,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_PWM2,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_PWM3,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_PWM4,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_GPT1,                 100 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPT2,                 100 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPT3,                 100 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPT4,                 100 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPT5,                 100 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPT6,                 100 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_WDOG,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_IPP_DO_CLKO1,         200 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_IPP_DO_CLKO2,         200 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_HDMI_REF_266M,        266 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_USDHC3,               400 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_MEDIA_MIPI_PHY1_REF,  300 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_MEDIA_DISP1_PIX,      250 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_MEDIA_CAM2_PIX,       277 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_MEDIA_LDB,            595 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_MEDIA_MIPI_TEST_BYTE, 200 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_ECSPI3,                80 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_PDM,                  200 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_SAI7,                  66666667 }, /* Datasheet claims 66MHz */
>+	{ IMX8MP_CLK_MAIN_AXI,             400 * HZ_PER_MHZ },
>+	{ /* sentinel */ },
>+};
>+
>+static const struct imx8mp_clock_constraints imx8mp_clock_nominal_constraints[] = {
>+	{ IMX8MP_CLK_M7_CORE,           600 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_ML_CORE,           800 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPU3D_CORE,        800 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPU3D_SHADER_CORE, 800 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPU2D_CORE,        800 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_AUDIO_AXI_SRC,     600 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_HSIO_AXI,          400 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_MEDIA_ISP,         400 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_VPU_BUS,           600 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_MEDIA_AXI,         400 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_HDMI_AXI,          400 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPU_AXI,           600 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPU_AHB,           300 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_NOC,               800 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_NOC_IO,            600 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_ML_AHB,            300 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_VPU_G1,            600 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_VPU_G2,            500 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_MEDIA_CAM1_PIX,    400 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_VPU_VC8000E,       400 * HZ_PER_MHZ }, /* Datasheet claims 500MHz */
>+	{ IMX8MP_CLK_DRAM_CORE,         800 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GIC,               400 * HZ_PER_MHZ },
>+	{ /* sentinel */ },
>+};
>+
>+static const struct imx8mp_clock_constraints imx8mp_clock_overdrive_constraints[] = {
>+	{ IMX8MP_CLK_M7_CORE,            800 * HZ_PER_MHZ},
>+	{ IMX8MP_CLK_ML_CORE,           1000 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPU3D_CORE,        1000 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPU3D_SHADER_CORE, 1000 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPU2D_CORE,        1000 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_AUDIO_AXI_SRC,      800 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_HSIO_AXI,           500 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_MEDIA_ISP,          500 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_VPU_BUS,            800 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_MEDIA_AXI,          500 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_HDMI_AXI,           500 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPU_AXI,            800 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GPU_AHB,            400 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_NOC,               1000 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_NOC_IO,             800 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_ML_AHB,             400 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_VPU_G1,             800 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_VPU_G2,             700 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_MEDIA_CAM1_PIX,     500 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_VPU_VC8000E,        500 * HZ_PER_MHZ }, /* Datasheet claims 400MHz */
>+	{ IMX8MP_CLK_DRAM_CORE,         1000 * HZ_PER_MHZ },
>+	{ IMX8MP_CLK_GIC,                500 * HZ_PER_MHZ },
>+	{ /* sentinel */ },
>+};
>+
>+static void imx8mp_clocks_apply_constraints(const struct imx8mp_clock_constraints constraints[])
>+{
>+	const struct imx8mp_clock_constraints *constr;
>+
>+	for (constr = constraints; constr->clkid; constr++)
>+		clk_hw_set_rate_range(hws[constr->clkid], 0, constr->maxrate);
>+}
>+
> static int imx8mp_clocks_probe(struct platform_device *pdev)
> {
> 	struct device *dev = &pdev->dev;
>@@ -714,6 +854,13 @@ static int imx8mp_clocks_probe(struct platform_device *pdev)
> 
> 	imx_check_clk_hws(hws, IMX8MP_CLK_END);
> 
>+	imx8mp_clocks_apply_constraints(imx8mp_clock_common_constraints);
>+
>+	if (of_property_read_bool(np, "fsl,nominal-mode"))
>+		imx8mp_clocks_apply_constraints(imx8mp_clock_nominal_constraints);
>+	else if (of_property_read_bool(np, "fsl,overdrive-mode"))
>+		imx8mp_clocks_apply_constraints(imx8mp_clock_overdrive_constraints);

As I replied, a boot parameter should be better? the mode is a soc level mode,
not just clock controller.

Thanks,
Peng

>+
> 	err = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, clk_hw_data);
> 	if (err < 0) {
> 		dev_err(dev, "failed to register hws for i.MX8MP\n");
>
>-- 
>2.39.5
>



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