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

Peng Fan
2024-12-20T05:12:39Z

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@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
>