diff mbox

[1/3] soc: amlogic: Add Meson GX Clock Measure driver

Message ID CAFBinCDBEbVSEzhM2WOhxNX1DZLiSrkeo7GWdxGzBpOUH3PKQw@mail.gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Martin Blumenstingl July 3, 2018, 7:18 p.m. UTC
Hi Neil,

On Tue, Jul 3, 2018 at 3:23 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
>
> The Amlogic Meson GX SoCs embeds a clock measurer IP to measure the internal
> clock paths frequencies.
> The precision is in the order of the MHz.
>
> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> ---
>  drivers/soc/amlogic/Kconfig                |   8 ++
>  drivers/soc/amlogic/Makefile               |   1 +
>  drivers/soc/amlogic/meson-gx-clk-measure.c | 224 +++++++++++++++++++++++++++++
>  3 files changed, 233 insertions(+)
>  create mode 100644 drivers/soc/amlogic/meson-gx-clk-measure.c
>
> diff --git a/drivers/soc/amlogic/Kconfig b/drivers/soc/amlogic/Kconfig
> index b04f6e4..4a3217d 100644
> --- a/drivers/soc/amlogic/Kconfig
> +++ b/drivers/soc/amlogic/Kconfig
> @@ -1,5 +1,13 @@
>  menu "Amlogic SoC drivers"
>
> +config MESON_GX_CLK_MEASURE
> +       bool "Amlogic Meson GX SoC Clock Measure driver"
> +       depends on ARCH_MESON || COMPILE_TEST
> +       default ARCH_MESON
> +       help
> +         Say yes to support of Measuring a set of internal SoC clocks
> +         from the debugfs interface.
> +
>  config MESON_GX_SOCINFO
>         bool "Amlogic Meson GX SoC Information driver"
>         depends on ARCH_MESON || COMPILE_TEST
> diff --git a/drivers/soc/amlogic/Makefile b/drivers/soc/amlogic/Makefile
> index 8fa3218..a0ad966 100644
> --- a/drivers/soc/amlogic/Makefile
> +++ b/drivers/soc/amlogic/Makefile
> @@ -1,3 +1,4 @@
> +obj-$(CONFIG_MESON_GX_CLK_MEASURE) += meson-gx-clk-measure.o
>  obj-$(CONFIG_MESON_GX_SOCINFO) += meson-gx-socinfo.o
>  obj-$(CONFIG_MESON_GX_PM_DOMAINS) += meson-gx-pwrc-vpu.o
>  obj-$(CONFIG_MESON_MX_SOCINFO) += meson-mx-socinfo.o
> diff --git a/drivers/soc/amlogic/meson-gx-clk-measure.c b/drivers/soc/amlogic/meson-gx-clk-measure.c
> new file mode 100644
> index 0000000..434d9f3
> --- /dev/null
> +++ b/drivers/soc/amlogic/meson-gx-clk-measure.c
> @@ -0,0 +1,224 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (c) 2017 BayLibre, SAS
> + * Author: Neil Armstrong <narmstrong@baylibre.com>
> + */
> +
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/bitfield.h>
> +#include <linux/seq_file.h>
> +#include <linux/debugfs.h>
> +#include <linux/regmap.h>
> +
> +#define MSR_CLK_DUTY           0x0
> +#define MSR_CLK_REG0           0x4
> +#define MSR_CLK_REG1           0x8
> +#define MSR_CLK_REG2           0xc
> +
> +#define MSR_CLK_DIV            GENMASK(15, 0)
> +#define MSR_ENABLE             BIT(16)
> +#define MSR_CONT               BIT(17) /* continuous measurement */
> +#define MSR_INTR               BIT(18) /* interrupts */
> +#define MSR_RUN                        BIT(19)
> +#define MSR_CLK_SRC            GENMASK(26, 20)
> +#define MSR_BUSY               BIT(31)
> +
> +#define MSR_VAL_MASK           GENMASK(15, 0)
> +
> +#define DIV_50US               64
> +
> +#define CLK_MSR_MAX            128
> +
> +struct meson_gx_msr {
> +       struct regmap *regmap;
> +};
> +
> +struct meson_gx_msr_id {
> +       struct meson_gx_msr *priv;
> +       unsigned int id;
> +       const char *name;
> +};
> +
> +#define CLK_MSR_ID(__id, __name) \
> +       [__id] = {.id = __id, .name = __name,}
> +
> +static struct meson_gx_msr_id clk_msr[CLK_MSR_MAX] = {
> +       CLK_MSR_ID(0, "ring_osc_out_ee_0"),
> +       CLK_MSR_ID(1, "ring_osc_out_ee_1"),
> +       CLK_MSR_ID(2, "ring_osc_out_ee_2"),
> +       CLK_MSR_ID(3, "a53_ring_osc"),
> +       CLK_MSR_ID(4, "gp0_pll"),
> +       CLK_MSR_ID(6, "enci"),
> +       CLK_MSR_ID(7, "clk81"),
> +       CLK_MSR_ID(8, "encp"),
> +       CLK_MSR_ID(9, "encl"),
> +       CLK_MSR_ID(10, "vdac"),
> +       CLK_MSR_ID(11, "rgmii_tx"),
> +       CLK_MSR_ID(12, "pdm"),
> +       CLK_MSR_ID(13, "amclk"),
> +       CLK_MSR_ID(14, "fec_0"),
> +       CLK_MSR_ID(15, "fec_1"),
> +       CLK_MSR_ID(16, "fec_2"),
> +       CLK_MSR_ID(17, "sys_pll_div16"),
> +       CLK_MSR_ID(18, "sys_cpu_div16"),
> +       CLK_MSR_ID(19, "hdmitx_sys"),
> +       CLK_MSR_ID(20, "rtc_osc_out"),
> +       CLK_MSR_ID(21, "i2s_in_src0"),
> +       CLK_MSR_ID(22, "eth_phy_ref"),
> +       CLK_MSR_ID(23, "hdmi_todig"),
> +       CLK_MSR_ID(26, "sc_int"),
> +       CLK_MSR_ID(28, "sar_adc"),
> +       CLK_MSR_ID(31, "mpll_test_out"),
> +       CLK_MSR_ID(32, "vdec"),
> +       CLK_MSR_ID(35, "mali"),
> +       CLK_MSR_ID(36, "hdmi_tx_pixel"),
> +       CLK_MSR_ID(37, "i958"),
> +       CLK_MSR_ID(38, "vdin_meas"),
> +       CLK_MSR_ID(39, "pcm_sclk"),
> +       CLK_MSR_ID(40, "pcm_mclk"),
> +       CLK_MSR_ID(41, "eth_rx_or_rmii"),
> +       CLK_MSR_ID(42, "mp0_out"),
> +       CLK_MSR_ID(43, "fclk_div5"),
> +       CLK_MSR_ID(44, "pwm_b"),
> +       CLK_MSR_ID(45, "pwm_a"),
> +       CLK_MSR_ID(46, "vpu"),
> +       CLK_MSR_ID(47, "ddr_dpll_pt"),
> +       CLK_MSR_ID(48, "mp1_out"),
> +       CLK_MSR_ID(49, "mp2_out"),
> +       CLK_MSR_ID(50, "mp3_out"),
> +       CLK_MSR_ID(51, "nand_core"),
> +       CLK_MSR_ID(52, "sd_emmc_b"),
> +       CLK_MSR_ID(53, "sd_emmc_a"),
> +       CLK_MSR_ID(55, "vid_pll_div_out"),
> +       CLK_MSR_ID(56, "cci"),
> +       CLK_MSR_ID(57, "wave420l_c"),
> +       CLK_MSR_ID(58, "wave420l_b"),
AFAIK the Chips&Media WAVE420L video codec is only available on GXM (S912)
I assume reading this on GXBB or GXL simply reads 0?

> +       CLK_MSR_ID(59, "hcodec"),
> +       CLK_MSR_ID(60, "alt_32k"),
> +       CLK_MSR_ID(61, "gpio_msr"),
> +       CLK_MSR_ID(62, "hevc"),
> +       CLK_MSR_ID(66, "vid_lock"),
> +       CLK_MSR_ID(70, "pwm_f"),
> +       CLK_MSR_ID(71, "pwm_e"),
> +       CLK_MSR_ID(72, "pwm_d"),
> +       CLK_MSR_ID(73, "pwm_C"),
should this be pwm_c (instead of pwm_C)?

> +       CLK_MSR_ID(75, "aoclkx2_int"),
> +       CLK_MSR_ID(76, "aoclk_int"),
> +       CLK_MSR_ID(77, "rng_ring_osc_0"),
> +       CLK_MSR_ID(78, "rng_ring_osc_1"),
> +       CLK_MSR_ID(79, "rng_ring_osc_2"),
> +       CLK_MSR_ID(80, "rng_ring_osc_3"),
> +       CLK_MSR_ID(81, "vapb"),
> +       CLK_MSR_ID(82, "ge2d"),
> +};
I did a quick check whether the clock IDs are really the same for all GX SoCs:
apart from clocks missing on older SoCs (see for example the WAVE420L
clocks above) there were only minor renames but no conflicts!

> +
> +static int meson_gx_measure_id(struct meson_gx_msr *priv, unsigned int id)
> +{
> +       unsigned int val;
> +       int ret;
> +
> +       regmap_write(priv->regmap, MSR_CLK_REG0, 0);
> +
> +       /* Set measurement gate to 50uS */
> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_CLK_DIV,
> +                          FIELD_PREP(MSR_CLK_DIV, DIV_50US));
> +
> +       /* Set ID */
> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_CLK_SRC,
> +                          FIELD_PREP(MSR_CLK_SRC, id));
> +
> +       /* Enable & Start */
> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0,
> +                          MSR_RUN | MSR_ENABLE,
> +                          MSR_RUN | MSR_ENABLE);
> +
> +       ret = regmap_read_poll_timeout(priv->regmap, MSR_CLK_REG0,
> +                                      val, !(val & MSR_BUSY), 10, 1000);
> +       if (ret)
> +               return ret;
> +
> +       /* Disable */
> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_ENABLE, 0);
> +
> +       /* Get the value in MHz*64 */
> +       regmap_read(priv->regmap, MSR_CLK_REG2, &val);
> +
> +       return (((val + 31) & MSR_VAL_MASK) / 64) * 1000000;
> +}
> +
> +static int clk_msr_show(struct seq_file *s, void *data)
> +{
> +       struct meson_gx_msr_id *clk_msr_id = s->private;
> +       int val;
> +
> +       val = meson_gx_measure_id(clk_msr_id->priv, clk_msr_id->id);
> +       if (val < 0)
> +               return val;
> +
> +       seq_printf(s, "%d\n", val);
> +
> +       return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(clk_msr);
have you considered modelling this as clock driver instead?

> +
> +static const struct regmap_config clk_msr_regmap_config = {
> +       .reg_bits = 32,
> +       .val_bits = 32,
> +       .reg_stride = 4,
> +       .max_register = MSR_CLK_REG2,
> +};
> +
> +static int meson_gx_msr_probe(struct platform_device *pdev)
> +{
> +       struct meson_gx_msr *priv;
> +       struct resource *res;
> +       struct dentry *root;
> +       void __iomem *base;
> +       int i;
> +
> +       priv = devm_kzalloc(&pdev->dev, sizeof(struct meson_gx_msr),
> +                           GFP_KERNEL);
> +       if (!priv)
> +               return -ENOMEM;
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       base = devm_ioremap_resource(&pdev->dev, res);
> +       if (IS_ERR(base)) {
> +               dev_err(&pdev->dev, "io resource mapping failed\n");
> +               return PTR_ERR(base);
> +       }
> +
> +       priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
> +                                             &clk_msr_regmap_config);
> +       if (IS_ERR(priv->regmap))
> +               return PTR_ERR(priv->regmap);
> +
> +       root = debugfs_create_dir("meson-clk-msr", NULL);
> +
> +       for (i = 0 ; i < CLK_MSR_MAX ; ++i) {
> +               if (!clk_msr[i].name)
> +                       continue;
> +
> +               clk_msr[i].priv = priv;
> +
> +               debugfs_create_file(clk_msr[i].name, 0444, root,
> +                                   &clk_msr[i], &clk_msr_fops);
> +       }
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id meson_gx_msr_match_table[] = {
> +       { .compatible = "amlogic,meson-gx-clk-measure" },
maybe pass the meson_gx_msr_id table here because it seems easy to add
support for AXG and Meson8/Meson8b/Meson8m2 later on


Regards
Martin
[82] = "Cts_ge2d_clk       ",
		[81] = "Cts_vapbclk        ",
		[80] = "Rng_ring_osc_clk[3]",
		[79] = "Rng_ring_osc_clk[2]",
		[78] = "Rng_ring_osc_clk[1]",
		[77] = "Rng_ring_osc_clk[0]",
		[76] = "cts_aoclk_int      ",
		[75] = "cts_aoclkx2_int    ",
		[74] = "0                  ",
		[73] = "cts_pwm_C_clk      ",
		[72] = "cts_pwm_D_clk      ",
		[71] = "cts_pwm_E_clk      ",
		[70] = "cts_pwm_F_clk      ",
		[69] = "0                  ",
		[68] = "0                  ",
		[67] = "0                  ",
		[66] = "cts_vid_lock_clk   ",
		[65] = "0                  ",
		[64] = "0                  ",
		[63] = "0                  ",
		[62] = "cts_hevc_clk       ",
		[61] = "gpio_clk_msr       ",
		[60] = "alt_32k_clk        ",
		[59] = "cts_hcodec_clk     ",
		[58] = "0                  ",
		[57] = "0					",
		[56] = "0					",
		[55] = "vid_pll_div_clk_out	",
		[54] = "0					",
		[53] = "Sd_emmc_clk_A		",
		[52] = "Sd_emmc_clk_B		",
		[51] = "Cts_nand_core_clk	",
		[50] = "Mp3_clk_out			",
		[49] = "mp2_clk_out			",
		[48] = "mp1_clk_out			",
		[47] = "ddr_dpll_pt_clk		",
		[46] = "cts_vpu_clk			",
		[45] = "cts_pwm_A_clk		",
		[44] = "cts_pwm_B_clk		",
		[43] = "fclk_div5			",
		[42] = "mp0_clk_out			",
		[41] = "eth_rx_clk_or_clk_rmii",
		[40] = "cts_pcm_mclk			",
		[39] = "cts_pcm_sclk			",
		[38] = "cts_vdin_meas_clk			",
		[37] = "cts_clk_i958			",
		[36] = "cts_hdmi_tx_pixel_clk ",
		[35] = "cts_mali_clk			",
		[34] = "0					",
		[33] = "0					",
		[32] = "cts_vdec_clk			",
		[31] = "MPLL_CLK_TEST_OUT	",
		[30] = "0					",
		[29] = "0					",
		[28] = "cts_sar_adc_clk					   ",
		[27] = "0					   ",
		[26] = "sc_clk_int			   ",
		[25] = "0					   ",
		[24] = "0					   ",
		[23] = "HDMI_CLK_TODIG		   ",
		[22] = "eth_phy_ref_clk		   ",
		[21] = "i2s_clk_in_src0		   ",
		[20] = "rtc_osc_clk_out		   ",
		[19] = "cts_hdmitx_sys_clk	   ",
		[18] = "sys_cpu_clk_div16		   ",
		[17] = "sys_pll_div16					   ",
		[16] = "cts_FEC_CLK_2		   ",
		[15] = "cts_FEC_CLK_1		   ",
		[14] = "cts_FEC_CLK_0		   ",
		[13] = "cts_amclk			   ",
		[12] = "Cts_pdm_clk			   ",
		[11] = "rgmii_tx_clk_to_phy	   ",
		[10] = "cts_vdac_clk			   ",
		[9] = "cts_encl_clk			  ",
		[8] = "cts_encp_clk			  ",
		[7] = "clk81					  ",
		[6] = "cts_enci_clk			  ",
		[5] = "0						  ",
		[4] = "gp0_pll_clk			  ",
		[3] = "A53_ring_osc_clk		  ",
		[2] = "am_ring_osc_clk_out_ee[2]",
		[1] = "am_ring_osc_clk_out_ee[1]",
		[0] = "am_ring_osc_clk_out_ee[0]",
[82] = "Cts_ge2d_clk       ",
		[81] = "Cts_vapbclk        ",
		[80] = "Rng_ring_osc_clk[3]",
		[79] = "Rng_ring_osc_clk[2]",
		[78] = "Rng_ring_osc_clk[1]",
		[77] = "Rng_ring_osc_clk[0]",
		[76] = "cts_aoclk_int      ",
		[75] = "cts_aoclkx2_int    ",
		[74] = "0                  ",
		[73] = "cts_pwm_C_clk      ",
		[72] = "cts_pwm_D_clk      ",
		[71] = "cts_pwm_E_clk      ",
		[70] = "cts_pwm_F_clk      ",
		[69] = "0                  ",
		[68] = "0                  ",
		[67] = "0                  ",
		[66] = "cts_vid_lock_clk   ",
		[65] = "0                  ",
		[64] = "0                  ",
		[63] = "0                  ",
		[62] = "cts_hevc_clk       ",
		[61] = "gpio_clk_msr       ",
		[60] = "alt_32k_clk        ",
		[59] = "cts_hcodec_clk     ",
		[58] = "cts_wave420l_bclk                  ",
		[57] = "cts_wave420l_cclk	",
		[56] = "cts_cci_clk			",
		[55] = "vid_pll_div_clk_out	",
		[54] = "0					",
		[53] = "Sd_emmc_clk_A		",
		[52] = "Sd_emmc_clk_B		",
		[51] = "Cts_nand_core_clk	",
		[50] = "Mp3_clk_out			",
		[49] = "mp2_clk_out			",
		[48] = "mp1_clk_out			",
		[47] = "ddr_dpll_pt_clk		",
		[46] = "cts_vpu_clk			",
		[45] = "cts_pwm_A_clk		",
		[44] = "cts_pwm_B_clk		",
		[43] = "fclk_div5			",
		[42] = "mp0_clk_out			",
		[41] = "eth_rx_clk_or_clk_rmii",
		[40] = "cts_pcm_mclk			",
		[39] = "cts_pcm_sclk			",
		[38] = "cts_vdin_meas_clk			",
		[37] = "cts_clk_i958			",
		[36] = "cts_hdmi_tx_pixel_clk ",
		[35] = "cts_mali_clk			",
		[34] = "0					",
		[33] = "0					",
		[32] = "cts_vdec_clk			",
		[31] = "MPLL_CLK_TEST_OUT	",
		[30] = "0					",
		[29] = "0					",
		[28] = "cts_sar_adc_clk					   ",
		[27] = "0					   ",
		[26] = "sc_clk_int			   ",
		[25] = "0					   ",
		[24] = "sys_cpu1_clk_div16			",
		[23] = "HDMI_CLK_TODIG		   ",
		[22] = "eth_phy_ref_clk		   ",
		[21] = "i2s_clk_in_src0		   ",
		[20] = "rtc_osc_clk_out		   ",
		[19] = "cts_hdmitx_sys_clk	   ",
		[18] = "sys_cpu_clk_div16		   ",
		[17] = "sys_pll_div16					   ",
		[16] = "cts_FEC_CLK_2		   ",
		[15] = "cts_FEC_CLK_1		   ",
		[14] = "cts_FEC_CLK_0		   ",
		[13] = "cts_amclk			   ",
		[12] = "Cts_pdm_clk			   ",
		[11] = "mac_eth_tx_clk	   ",
		[10] = "cts_vdac_clk			   ",
		[9] = "cts_encl_clk			  ",
		[8] = "cts_encp_clk			  ",
		[7] = "clk81					  ",
		[6] = "cts_enci_clk			  ",
		[5] = "0						  ",
		[4] = "gp0_pll_clk			  ",
		[3] = "A53_ring_osc_clk		  ",
		[2] = "am_ring_osc_clk_out_ee[2]",
		[1] = "am_ring_osc_clk_out_ee[1]",
		[0] = "am_ring_osc_clk_out_ee[0]",
[82] = "Cts_ge2d_clk       ",
		[81] = "Cts_vapbclk        ",
		[80] = "Rng_ring_osc_clk[3]",
		[79] = "Rng_ring_osc_clk[2]",
		[78] = "Rng_ring_osc_clk[1]",
		[77] = "Rng_ring_osc_clk[0]",
		[76] = "cts_aoclk_int      ",
		[75] = "cts_aoclkx2_int    ",
		[74] = "0                  ",
		[73] = "cts_pwm_C_clk      ",
		[72] = "cts_pwm_D_clk      ",
		[71] = "cts_pwm_E_clk      ",
		[70] = "cts_pwm_F_clk      ",
		[69] = "0                  ",
		[68] = "0                  ",
		[67] = "0                  ",
		[66] = "cts_vid_lock_clk   ",
		[65] = "0                  ",
		[64] = "0                  ",
		[63] = "0                  ",
		[62] = "cts_hevc_clk       ",
		[61] = "gpio_clk_msr       ",
		[60] = "alt_32k_clk        ",
		[59] = "cts_hcodec_clk     ",
		[58] = "0                  ",
		[57] = "0					",
		[56] = "0					",
		[55] = "vid_pll_div_clk_out	",
		[54] = "0					",
		[53] = "Sd_emmc_clk_A		",
		[52] = "Sd_emmc_clk_B		",
		[51] = "Cts_nand_core_clk	",
		[50] = "Mp3_clk_out			",
		[49] = "mp2_clk_out			",
		[48] = "mp1_clk_out			",
		[47] = "ddr_dpll_pt_clk		",
		[46] = "cts_vpu_clk			",
		[45] = "cts_pwm_A_clk		",
		[44] = "cts_pwm_B_clk		",
		[43] = "fclk_div5			",
		[42] = "mp0_clk_out			",
		[41] = "eth_rx_clk_or_clk_rmii",
		[40] = "cts_pcm_mclk			",
		[39] = "cts_pcm_sclk			",
		[38] = "0					",
		[37] = "cts_clk_i958			",
		[36] = "cts_hdmi_tx_pixel_clk ",
		[35] = "cts_mali_clk			",
		[34] = "0					",
		[33] = "0					",
		[32] = "cts_vdec_clk			",
		[31] = "MPLL_CLK_TEST_OUT	",
		[30] = "0					",
		[29] = "0					",
		[28] = "0					   ",
		[27] = "0					   ",
		[26] = "sc_clk_int			   ",
		[25] = "0					   ",
		[24] = "0					   ",
		[23] = "HDMI_CLK_TODIG		   ",
		[22] = "eth_phy_ref_clk		   ",
		[21] = "i2s_clk_in_src0		   ",
		[20] = "rtc_osc_clk_out		   ",
		[19] = "cts_hdmitx_sys_clk	   ",
		[18] = "A53_clk_div16		   ",
		[17] = "0					   ",
		[16] = "cts_FEC_CLK_2		   ",
		[15] = "cts_FEC_CLK_1		   ",
		[14] = "cts_FEC_CLK_0		   ",
		[13] = "cts_amclk			   ",
		[12] = "Cts_pdm_clk			   ",
		[11] = "rgmii_tx_clk_to_phy	   ",
		[10] = "cts_vdac_clk			   ",
		[9] = "cts_encl_clk			  " ,
		[8] = "cts_encp_clk			  " ,
		[7] = "clk81					  " ,
		[6] = "cts_enci_clk			  " ,
		[5] = "0						  " ,
		[4] = "gp0_pll_clk			  " ,
		[3] = "A53_ring_osc_clk		  " ,
		[2] = "am_ring_osc_clk_out_ee[2]" ,
		[1] = "am_ring_osc_clk_out_ee[1]" ,
		[0] = "am_ring_osc_clk_out_ee[0]" ,

Comments

Neil Armstrong July 4, 2018, 8:41 a.m. UTC | #1
Hi Martin,

On 03/07/2018 21:18, Martin Blumenstingl wrote:
> Hi Neil,
> 
> On Tue, Jul 3, 2018 at 3:23 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
>>
>> The Amlogic Meson GX SoCs embeds a clock measurer IP to measure the internal
>> clock paths frequencies.
>> The precision is in the order of the MHz.
>>
>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
>> ---
>>  drivers/soc/amlogic/Kconfig                |   8 ++
>>  drivers/soc/amlogic/Makefile               |   1 +
>>  drivers/soc/amlogic/meson-gx-clk-measure.c | 224 +++++++++++++++++++++++++++++
>>  3 files changed, 233 insertions(+)
>>  create mode 100644 drivers/soc/amlogic/meson-gx-clk-measure.c
>>
>> diff --git a/drivers/soc/amlogic/Kconfig b/drivers/soc/amlogic/Kconfig
>> index b04f6e4..4a3217d 100644
>> --- a/drivers/soc/amlogic/Kconfig
>> +++ b/drivers/soc/amlogic/Kconfig
>> @@ -1,5 +1,13 @@
>>  menu "Amlogic SoC drivers"
>>
>> +config MESON_GX_CLK_MEASURE
>> +       bool "Amlogic Meson GX SoC Clock Measure driver"
>> +       depends on ARCH_MESON || COMPILE_TEST
>> +       default ARCH_MESON
>> +       help
>> +         Say yes to support of Measuring a set of internal SoC clocks
>> +         from the debugfs interface.
>> +
>>  config MESON_GX_SOCINFO
>>         bool "Amlogic Meson GX SoC Information driver"
>>         depends on ARCH_MESON || COMPILE_TEST
>> diff --git a/drivers/soc/amlogic/Makefile b/drivers/soc/amlogic/Makefile
>> index 8fa3218..a0ad966 100644
>> --- a/drivers/soc/amlogic/Makefile
>> +++ b/drivers/soc/amlogic/Makefile
>> @@ -1,3 +1,4 @@
>> +obj-$(CONFIG_MESON_GX_CLK_MEASURE) += meson-gx-clk-measure.o
>>  obj-$(CONFIG_MESON_GX_SOCINFO) += meson-gx-socinfo.o
>>  obj-$(CONFIG_MESON_GX_PM_DOMAINS) += meson-gx-pwrc-vpu.o
>>  obj-$(CONFIG_MESON_MX_SOCINFO) += meson-mx-socinfo.o
>> diff --git a/drivers/soc/amlogic/meson-gx-clk-measure.c b/drivers/soc/amlogic/meson-gx-clk-measure.c
>> new file mode 100644
>> index 0000000..434d9f3
>> --- /dev/null
>> +++ b/drivers/soc/amlogic/meson-gx-clk-measure.c

[...]

>> +       CLK_MSR_ID(57, "wave420l_c"),
>> +       CLK_MSR_ID(58, "wave420l_b"),
> AFAIK the Chips&Media WAVE420L video codec is only available on GXM (S912)
> I assume reading this on GXBB or GXL simply reads 0?

Yes

> 
>> +       CLK_MSR_ID(59, "hcodec"),
>> +       CLK_MSR_ID(60, "alt_32k"),
>> +       CLK_MSR_ID(61, "gpio_msr"),
>> +       CLK_MSR_ID(62, "hevc"),
>> +       CLK_MSR_ID(66, "vid_lock"),
>> +       CLK_MSR_ID(70, "pwm_f"),
>> +       CLK_MSR_ID(71, "pwm_e"),
>> +       CLK_MSR_ID(72, "pwm_d"),
>> +       CLK_MSR_ID(73, "pwm_C"),
> should this be pwm_c (instead of pwm_C)?
> 
>> +       CLK_MSR_ID(75, "aoclkx2_int"),
>> +       CLK_MSR_ID(76, "aoclk_int"),
>> +       CLK_MSR_ID(77, "rng_ring_osc_0"),
>> +       CLK_MSR_ID(78, "rng_ring_osc_1"),
>> +       CLK_MSR_ID(79, "rng_ring_osc_2"),
>> +       CLK_MSR_ID(80, "rng_ring_osc_3"),
>> +       CLK_MSR_ID(81, "vapb"),
>> +       CLK_MSR_ID(82, "ge2d"),
>> +};
> I did a quick check whether the clock IDs are really the same for all GX SoCs:
> apart from clocks missing on older SoCs (see for example the WAVE420L
> clocks above) there were only minor renames but no conflicts!

I did the same work ! I will add this detail to the commit log.
Thanks for checking ;-)

> 
>> +
>> +static int meson_gx_measure_id(struct meson_gx_msr *priv, unsigned int id)
>> +{
>> +       unsigned int val;
>> +       int ret;
>> +
>> +       regmap_write(priv->regmap, MSR_CLK_REG0, 0);
>> +
>> +       /* Set measurement gate to 50uS */
>> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_CLK_DIV,
>> +                          FIELD_PREP(MSR_CLK_DIV, DIV_50US));
>> +
>> +       /* Set ID */
>> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_CLK_SRC,
>> +                          FIELD_PREP(MSR_CLK_SRC, id));
>> +
>> +       /* Enable & Start */
>> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0,
>> +                          MSR_RUN | MSR_ENABLE,
>> +                          MSR_RUN | MSR_ENABLE);
>> +
>> +       ret = regmap_read_poll_timeout(priv->regmap, MSR_CLK_REG0,
>> +                                      val, !(val & MSR_BUSY), 10, 1000);
>> +       if (ret)
>> +               return ret;
>> +
>> +       /* Disable */
>> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_ENABLE, 0);
>> +
>> +       /* Get the value in MHz*64 */
>> +       regmap_read(priv->regmap, MSR_CLK_REG2, &val);
>> +
>> +       return (((val + 31) & MSR_VAL_MASK) / 64) * 1000000;
>> +}
>> +
>> +static int clk_msr_show(struct seq_file *s, void *data)
>> +{
>> +       struct meson_gx_msr_id *clk_msr_id = s->private;
>> +       int val;
>> +
>> +       val = meson_gx_measure_id(clk_msr_id->priv, clk_msr_id->id);
>> +       if (val < 0)
>> +               return val;
>> +
>> +       seq_printf(s, "%d\n", val);

With jerome, we managed to have a much higher precision by cycling over the divider
and checking when the counter overflows. And I will print the precision in the clock debugfs
entry.

>> +
>> +       return 0;
>> +}
>> +DEFINE_SHOW_ATTRIBUTE(clk_msr);
> have you considered modelling this as clock driver instead?

Yes, but it can wait.
Actually this clk-msr can be feed to GEN_CLK and be outputted to a pad,
but all this is only for debug, so we can stick to debugfs for now.

Question, should I separate the clocks in a subdirectory and add a summary file like
for the clk debugfs ?


/sys/kernel/debug/meson-clk-msr
------------------|--- summary
------------------|--- clks
-----------------------|--- ring_osc_out_ee_0
...
-----------------------|--- ge2d

?

> 
>> +
>> +static const struct regmap_config clk_msr_regmap_config = {
>> +       .reg_bits = 32,
>> +       .val_bits = 32,
>> +       .reg_stride = 4,
>> +       .max_register = MSR_CLK_REG2,
>> +};
>> +
>> +static int meson_gx_msr_probe(struct platform_device *pdev)
>> +{
>> +       struct meson_gx_msr *priv;
>> +       struct resource *res;
>> +       struct dentry *root;
>> +       void __iomem *base;
>> +       int i;
>> +
>> +       priv = devm_kzalloc(&pdev->dev, sizeof(struct meson_gx_msr),
>> +                           GFP_KERNEL);
>> +       if (!priv)
>> +               return -ENOMEM;
>> +
>> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +       base = devm_ioremap_resource(&pdev->dev, res);
>> +       if (IS_ERR(base)) {
>> +               dev_err(&pdev->dev, "io resource mapping failed\n");
>> +               return PTR_ERR(base);
>> +       }
>> +
>> +       priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
>> +                                             &clk_msr_regmap_config);
>> +       if (IS_ERR(priv->regmap))
>> +               return PTR_ERR(priv->regmap);
>> +
>> +       root = debugfs_create_dir("meson-clk-msr", NULL);
>> +
>> +       for (i = 0 ; i < CLK_MSR_MAX ; ++i) {
>> +               if (!clk_msr[i].name)
>> +                       continue;
>> +
>> +               clk_msr[i].priv = priv;
>> +
>> +               debugfs_create_file(clk_msr[i].name, 0444, root,
>> +                                   &clk_msr[i], &clk_msr_fops);
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +static const struct of_device_id meson_gx_msr_match_table[] = {
>> +       { .compatible = "amlogic,meson-gx-clk-measure" },
> maybe pass the meson_gx_msr_id table here because it seems easy to add
> support for AXG and Meson8/Meson8b/Meson8m2 later on

Yes, I will rename the driver to be generic and pass the table as match data.

> 
> 
> Regards
> Martin
> 

Thanks for reviewing !

Neil
Martin Blumenstingl July 4, 2018, 1:44 p.m. UTC | #2
Hi Neil,

On Wed, Jul 4, 2018 at 10:41 AM Neil Armstrong <narmstrong@baylibre.com> wrote:
>
> Hi Martin,
>
> On 03/07/2018 21:18, Martin Blumenstingl wrote:
> > Hi Neil,
> >
> > On Tue, Jul 3, 2018 at 3:23 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
> >>
> >> The Amlogic Meson GX SoCs embeds a clock measurer IP to measure the internal
> >> clock paths frequencies.
> >> The precision is in the order of the MHz.
> >>
> >> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> >> ---
> >>  drivers/soc/amlogic/Kconfig                |   8 ++
> >>  drivers/soc/amlogic/Makefile               |   1 +
> >>  drivers/soc/amlogic/meson-gx-clk-measure.c | 224 +++++++++++++++++++++++++++++
> >>  3 files changed, 233 insertions(+)
> >>  create mode 100644 drivers/soc/amlogic/meson-gx-clk-measure.c
> >>
> >> diff --git a/drivers/soc/amlogic/Kconfig b/drivers/soc/amlogic/Kconfig
> >> index b04f6e4..4a3217d 100644
> >> --- a/drivers/soc/amlogic/Kconfig
> >> +++ b/drivers/soc/amlogic/Kconfig
> >> @@ -1,5 +1,13 @@
> >>  menu "Amlogic SoC drivers"
> >>
> >> +config MESON_GX_CLK_MEASURE
> >> +       bool "Amlogic Meson GX SoC Clock Measure driver"
> >> +       depends on ARCH_MESON || COMPILE_TEST
> >> +       default ARCH_MESON
> >> +       help
> >> +         Say yes to support of Measuring a set of internal SoC clocks
> >> +         from the debugfs interface.
> >> +
> >>  config MESON_GX_SOCINFO
> >>         bool "Amlogic Meson GX SoC Information driver"
> >>         depends on ARCH_MESON || COMPILE_TEST
> >> diff --git a/drivers/soc/amlogic/Makefile b/drivers/soc/amlogic/Makefile
> >> index 8fa3218..a0ad966 100644
> >> --- a/drivers/soc/amlogic/Makefile
> >> +++ b/drivers/soc/amlogic/Makefile
> >> @@ -1,3 +1,4 @@
> >> +obj-$(CONFIG_MESON_GX_CLK_MEASURE) += meson-gx-clk-measure.o
> >>  obj-$(CONFIG_MESON_GX_SOCINFO) += meson-gx-socinfo.o
> >>  obj-$(CONFIG_MESON_GX_PM_DOMAINS) += meson-gx-pwrc-vpu.o
> >>  obj-$(CONFIG_MESON_MX_SOCINFO) += meson-mx-socinfo.o
> >> diff --git a/drivers/soc/amlogic/meson-gx-clk-measure.c b/drivers/soc/amlogic/meson-gx-clk-measure.c
> >> new file mode 100644
> >> index 0000000..434d9f3
> >> --- /dev/null
> >> +++ b/drivers/soc/amlogic/meson-gx-clk-measure.c
>
> [...]
>
> >> +       CLK_MSR_ID(57, "wave420l_c"),
> >> +       CLK_MSR_ID(58, "wave420l_b"),
> > AFAIK the Chips&Media WAVE420L video codec is only available on GXM (S912)
> > I assume reading this on GXBB or GXL simply reads 0?
>
> Yes
>
> >
> >> +       CLK_MSR_ID(59, "hcodec"),
> >> +       CLK_MSR_ID(60, "alt_32k"),
> >> +       CLK_MSR_ID(61, "gpio_msr"),
> >> +       CLK_MSR_ID(62, "hevc"),
> >> +       CLK_MSR_ID(66, "vid_lock"),
> >> +       CLK_MSR_ID(70, "pwm_f"),
> >> +       CLK_MSR_ID(71, "pwm_e"),
> >> +       CLK_MSR_ID(72, "pwm_d"),
> >> +       CLK_MSR_ID(73, "pwm_C"),
> > should this be pwm_c (instead of pwm_C)?
> >
> >> +       CLK_MSR_ID(75, "aoclkx2_int"),
> >> +       CLK_MSR_ID(76, "aoclk_int"),
> >> +       CLK_MSR_ID(77, "rng_ring_osc_0"),
> >> +       CLK_MSR_ID(78, "rng_ring_osc_1"),
> >> +       CLK_MSR_ID(79, "rng_ring_osc_2"),
> >> +       CLK_MSR_ID(80, "rng_ring_osc_3"),
> >> +       CLK_MSR_ID(81, "vapb"),
> >> +       CLK_MSR_ID(82, "ge2d"),
> >> +};
> > I did a quick check whether the clock IDs are really the same for all GX SoCs:
> > apart from clocks missing on older SoCs (see for example the WAVE420L
> > clocks above) there were only minor renames but no conflicts!
>
> I did the same work ! I will add this detail to the commit log.
> Thanks for checking ;-)
:)

> >
> >> +
> >> +static int meson_gx_measure_id(struct meson_gx_msr *priv, unsigned int id)
> >> +{
> >> +       unsigned int val;
> >> +       int ret;
> >> +
> >> +       regmap_write(priv->regmap, MSR_CLK_REG0, 0);
> >> +
> >> +       /* Set measurement gate to 50uS */
> >> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_CLK_DIV,
> >> +                          FIELD_PREP(MSR_CLK_DIV, DIV_50US));
> >> +
> >> +       /* Set ID */
> >> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_CLK_SRC,
> >> +                          FIELD_PREP(MSR_CLK_SRC, id));
> >> +
> >> +       /* Enable & Start */
> >> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0,
> >> +                          MSR_RUN | MSR_ENABLE,
> >> +                          MSR_RUN | MSR_ENABLE);
> >> +
> >> +       ret = regmap_read_poll_timeout(priv->regmap, MSR_CLK_REG0,
> >> +                                      val, !(val & MSR_BUSY), 10, 1000);
> >> +       if (ret)
> >> +               return ret;
> >> +
> >> +       /* Disable */
> >> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_ENABLE, 0);
> >> +
> >> +       /* Get the value in MHz*64 */
> >> +       regmap_read(priv->regmap, MSR_CLK_REG2, &val);
> >> +
> >> +       return (((val + 31) & MSR_VAL_MASK) / 64) * 1000000;
> >> +}
> >> +
> >> +static int clk_msr_show(struct seq_file *s, void *data)
> >> +{
> >> +       struct meson_gx_msr_id *clk_msr_id = s->private;
> >> +       int val;
> >> +
> >> +       val = meson_gx_measure_id(clk_msr_id->priv, clk_msr_id->id);
> >> +       if (val < 0)
> >> +               return val;
> >> +
> >> +       seq_printf(s, "%d\n", val);
>
> With jerome, we managed to have a much higher precision by cycling over the divider
> and checking when the counter overflows. And I will print the precision in the clock debugfs
> entry.
great that you could even improve the precision!

> >> +
> >> +       return 0;
> >> +}
> >> +DEFINE_SHOW_ATTRIBUTE(clk_msr);
> > have you considered modelling this as clock driver instead?
>
> Yes, but it can wait.
> Actually this clk-msr can be feed to GEN_CLK and be outputted to a pad,
> but all this is only for debug, so we can stick to debugfs for now.
>
> Question, should I separate the clocks in a subdirectory and add a summary file like
> for the clk debugfs ?
>
>
> /sys/kernel/debug/meson-clk-msr
> ------------------|--- summary
> ------------------|--- clks
> -----------------------|--- ring_osc_out_ee_0
> ...
> -----------------------|--- ge2d
>
> ?
this is exactly why I was curious if you considered implementing this
as clock driver instead
based on your description above each measured clock will have the
following properties:
- id (passed to the clkmsr IP block)
- name (human readable name)
- clock rate
- accuracy

doesn't CCF provide everything except "id"? you'll even get the summary

can you explain how you would use the clkmsr output?
here's how I would use it:
- assume I'm debugging something broken
- I suspect that it may be due to the clock setup
- grep "suspicious-clock" /sys/kernel/debug/clk/clk_summary
- compare the grep output with /sys/kernel/debug/meson-clk-msr/suspicious-clock

if it was a CCF driver I could simply do:
grep "suspicious-clock" /sys/kernel/debug/clk/clk_summary
-> this would return "suspicious-clock" (which is what the kernel can
configure) and "clkmsr_suspicious-clock" (which is what clkmsr reads)

> >
> >> +
> >> +static const struct regmap_config clk_msr_regmap_config = {
> >> +       .reg_bits = 32,
> >> +       .val_bits = 32,
> >> +       .reg_stride = 4,
> >> +       .max_register = MSR_CLK_REG2,
> >> +};
> >> +
> >> +static int meson_gx_msr_probe(struct platform_device *pdev)
> >> +{
> >> +       struct meson_gx_msr *priv;
> >> +       struct resource *res;
> >> +       struct dentry *root;
> >> +       void __iomem *base;
> >> +       int i;
> >> +
> >> +       priv = devm_kzalloc(&pdev->dev, sizeof(struct meson_gx_msr),
> >> +                           GFP_KERNEL);
> >> +       if (!priv)
> >> +               return -ENOMEM;
> >> +
> >> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >> +       base = devm_ioremap_resource(&pdev->dev, res);
> >> +       if (IS_ERR(base)) {
> >> +               dev_err(&pdev->dev, "io resource mapping failed\n");
> >> +               return PTR_ERR(base);
> >> +       }
> >> +
> >> +       priv->regmap = devm_regmap_init_mmio(&pdev->dev, base,
> >> +                                             &clk_msr_regmap_config);
> >> +       if (IS_ERR(priv->regmap))
> >> +               return PTR_ERR(priv->regmap);
> >> +
> >> +       root = debugfs_create_dir("meson-clk-msr", NULL);
> >> +
> >> +       for (i = 0 ; i < CLK_MSR_MAX ; ++i) {
> >> +               if (!clk_msr[i].name)
> >> +                       continue;
> >> +
> >> +               clk_msr[i].priv = priv;
> >> +
> >> +               debugfs_create_file(clk_msr[i].name, 0444, root,
> >> +                                   &clk_msr[i], &clk_msr_fops);
> >> +       }
> >> +
> >> +       return 0;
> >> +}
> >> +
> >> +static const struct of_device_id meson_gx_msr_match_table[] = {
> >> +       { .compatible = "amlogic,meson-gx-clk-measure" },
> > maybe pass the meson_gx_msr_id table here because it seems easy to add
> > support for AXG and Meson8/Meson8b/Meson8m2 later on
>
> Yes, I will rename the driver to be generic and pass the table as match data.
great, thank you!


Regards
Martin
Kevin Hilman July 9, 2018, 9:41 p.m. UTC | #3
Martin Blumenstingl <martin.blumenstingl@googlemail.com> writes:

> Hi Neil,
>
> On Wed, Jul 4, 2018 at 10:41 AM Neil Armstrong <narmstrong@baylibre.com> wrote:
>>
>> Hi Martin,
>>
>> On 03/07/2018 21:18, Martin Blumenstingl wrote:
>> > Hi Neil,
>> >
>> > On Tue, Jul 3, 2018 at 3:23 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
>> >>
>> >> The Amlogic Meson GX SoCs embeds a clock measurer IP to measure the internal
>> >> clock paths frequencies.
>> >> The precision is in the order of the MHz.
>> >>
>> >> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
>> >> ---
>> >>  drivers/soc/amlogic/Kconfig                |   8 ++
>> >>  drivers/soc/amlogic/Makefile               |   1 +
>> >>  drivers/soc/amlogic/meson-gx-clk-measure.c | 224 +++++++++++++++++++++++++++++
>> >>  3 files changed, 233 insertions(+)
>> >>  create mode 100644 drivers/soc/amlogic/meson-gx-clk-measure.c
>> >>
>> >> diff --git a/drivers/soc/amlogic/Kconfig b/drivers/soc/amlogic/Kconfig
>> >> index b04f6e4..4a3217d 100644
>> >> --- a/drivers/soc/amlogic/Kconfig
>> >> +++ b/drivers/soc/amlogic/Kconfig
>> >> @@ -1,5 +1,13 @@
>> >>  menu "Amlogic SoC drivers"
>> >>
>> >> +config MESON_GX_CLK_MEASURE
>> >> +       bool "Amlogic Meson GX SoC Clock Measure driver"
>> >> +       depends on ARCH_MESON || COMPILE_TEST
>> >> +       default ARCH_MESON
>> >> +       help
>> >> +         Say yes to support of Measuring a set of internal SoC clocks
>> >> +         from the debugfs interface.
>> >> +
>> >>  config MESON_GX_SOCINFO
>> >>         bool "Amlogic Meson GX SoC Information driver"
>> >>         depends on ARCH_MESON || COMPILE_TEST
>> >> diff --git a/drivers/soc/amlogic/Makefile b/drivers/soc/amlogic/Makefile
>> >> index 8fa3218..a0ad966 100644
>> >> --- a/drivers/soc/amlogic/Makefile
>> >> +++ b/drivers/soc/amlogic/Makefile
>> >> @@ -1,3 +1,4 @@
>> >> +obj-$(CONFIG_MESON_GX_CLK_MEASURE) += meson-gx-clk-measure.o
>> >>  obj-$(CONFIG_MESON_GX_SOCINFO) += meson-gx-socinfo.o
>> >>  obj-$(CONFIG_MESON_GX_PM_DOMAINS) += meson-gx-pwrc-vpu.o
>> >>  obj-$(CONFIG_MESON_MX_SOCINFO) += meson-mx-socinfo.o
>> >> diff --git a/drivers/soc/amlogic/meson-gx-clk-measure.c b/drivers/soc/amlogic/meson-gx-clk-measure.c
>> >> new file mode 100644
>> >> index 0000000..434d9f3
>> >> --- /dev/null
>> >> +++ b/drivers/soc/amlogic/meson-gx-clk-measure.c
>>
>> [...]
>>
>> >> +       CLK_MSR_ID(57, "wave420l_c"),
>> >> +       CLK_MSR_ID(58, "wave420l_b"),
>> > AFAIK the Chips&Media WAVE420L video codec is only available on GXM (S912)
>> > I assume reading this on GXBB or GXL simply reads 0?
>>
>> Yes
>>
>> >
>> >> +       CLK_MSR_ID(59, "hcodec"),
>> >> +       CLK_MSR_ID(60, "alt_32k"),
>> >> +       CLK_MSR_ID(61, "gpio_msr"),
>> >> +       CLK_MSR_ID(62, "hevc"),
>> >> +       CLK_MSR_ID(66, "vid_lock"),
>> >> +       CLK_MSR_ID(70, "pwm_f"),
>> >> +       CLK_MSR_ID(71, "pwm_e"),
>> >> +       CLK_MSR_ID(72, "pwm_d"),
>> >> +       CLK_MSR_ID(73, "pwm_C"),
>> > should this be pwm_c (instead of pwm_C)?
>> >
>> >> +       CLK_MSR_ID(75, "aoclkx2_int"),
>> >> +       CLK_MSR_ID(76, "aoclk_int"),
>> >> +       CLK_MSR_ID(77, "rng_ring_osc_0"),
>> >> +       CLK_MSR_ID(78, "rng_ring_osc_1"),
>> >> +       CLK_MSR_ID(79, "rng_ring_osc_2"),
>> >> +       CLK_MSR_ID(80, "rng_ring_osc_3"),
>> >> +       CLK_MSR_ID(81, "vapb"),
>> >> +       CLK_MSR_ID(82, "ge2d"),
>> >> +};
>> > I did a quick check whether the clock IDs are really the same for all GX SoCs:
>> > apart from clocks missing on older SoCs (see for example the WAVE420L
>> > clocks above) there were only minor renames but no conflicts!
>>
>> I did the same work ! I will add this detail to the commit log.
>> Thanks for checking ;-)
> :)
>
>> >
>> >> +
>> >> +static int meson_gx_measure_id(struct meson_gx_msr *priv, unsigned int id)
>> >> +{
>> >> +       unsigned int val;
>> >> +       int ret;
>> >> +
>> >> +       regmap_write(priv->regmap, MSR_CLK_REG0, 0);
>> >> +
>> >> +       /* Set measurement gate to 50uS */
>> >> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_CLK_DIV,
>> >> +                          FIELD_PREP(MSR_CLK_DIV, DIV_50US));
>> >> +
>> >> +       /* Set ID */
>> >> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_CLK_SRC,
>> >> +                          FIELD_PREP(MSR_CLK_SRC, id));
>> >> +
>> >> +       /* Enable & Start */
>> >> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0,
>> >> +                          MSR_RUN | MSR_ENABLE,
>> >> +                          MSR_RUN | MSR_ENABLE);
>> >> +
>> >> +       ret = regmap_read_poll_timeout(priv->regmap, MSR_CLK_REG0,
>> >> +                                      val, !(val & MSR_BUSY), 10, 1000);
>> >> +       if (ret)
>> >> +               return ret;
>> >> +
>> >> +       /* Disable */
>> >> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_ENABLE, 0);
>> >> +
>> >> +       /* Get the value in MHz*64 */
>> >> +       regmap_read(priv->regmap, MSR_CLK_REG2, &val);
>> >> +
>> >> +       return (((val + 31) & MSR_VAL_MASK) / 64) * 1000000;
>> >> +}
>> >> +
>> >> +static int clk_msr_show(struct seq_file *s, void *data)
>> >> +{
>> >> +       struct meson_gx_msr_id *clk_msr_id = s->private;
>> >> +       int val;
>> >> +
>> >> +       val = meson_gx_measure_id(clk_msr_id->priv, clk_msr_id->id);
>> >> +       if (val < 0)
>> >> +               return val;
>> >> +
>> >> +       seq_printf(s, "%d\n", val);
>>
>> With jerome, we managed to have a much higher precision by cycling over the divider
>> and checking when the counter overflows. And I will print the precision in the clock debugfs
>> entry.
> great that you could even improve the precision!
>
>> >> +
>> >> +       return 0;
>> >> +}
>> >> +DEFINE_SHOW_ATTRIBUTE(clk_msr);
>> > have you considered modelling this as clock driver instead?
>>
>> Yes, but it can wait.
>> Actually this clk-msr can be feed to GEN_CLK and be outputted to a pad,
>> but all this is only for debug, so we can stick to debugfs for now.
>>
>> Question, should I separate the clocks in a subdirectory and add a summary file like
>> for the clk debugfs ?
>>
>>
>> /sys/kernel/debug/meson-clk-msr
>> ------------------|--- summary
>> ------------------|--- clks
>> -----------------------|--- ring_osc_out_ee_0
>> ...
>> -----------------------|--- ge2d
>>
>> ?
> this is exactly why I was curious if you considered implementing this
> as clock driver instead
> based on your description above each measured clock will have the
> following properties:
> - id (passed to the clkmsr IP block)
> - name (human readable name)
> - clock rate
> - accuracy
>
> doesn't CCF provide everything except "id"? you'll even get the summary
>
> can you explain how you would use the clkmsr output?
> here's how I would use it:
> - assume I'm debugging something broken
> - I suspect that it may be due to the clock setup
> - grep "suspicious-clock" /sys/kernel/debug/clk/clk_summary
> - compare the grep output with /sys/kernel/debug/meson-clk-msr/suspicious-clock
>
> if it was a CCF driver I could simply do:
> grep "suspicious-clock" /sys/kernel/debug/clk/clk_summary
> -> this would return "suspicious-clock" (which is what the kernel can
> configure) and "clkmsr_suspicious-clock" (which is what clkmsr reads)

Even futther, Couldn't this measure IP be used by the current CCF code
(as an additonal, optional property) such the the debugfs clk_summary
uses it directly?

Kevin
Neil Armstrong July 11, 2018, 8:37 a.m. UTC | #4
On 09/07/2018 23:41, Kevin Hilman wrote:
> Martin Blumenstingl <martin.blumenstingl@googlemail.com> writes:
> 
>> Hi Neil,
>>
>> On Wed, Jul 4, 2018 at 10:41 AM Neil Armstrong <narmstrong@baylibre.com> wrote:
>>>
>>> Hi Martin,
>>>
>>> On 03/07/2018 21:18, Martin Blumenstingl wrote:
>>>> Hi Neil,
>>>>
>>>> On Tue, Jul 3, 2018 at 3:23 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
>>>>>
>>>>> The Amlogic Meson GX SoCs embeds a clock measurer IP to measure the internal
>>>>> clock paths frequencies.
>>>>> The precision is in the order of the MHz.
>>>>>
>>>>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
>>>>> ---
>>>>>  drivers/soc/amlogic/Kconfig                |   8 ++
>>>>>  drivers/soc/amlogic/Makefile               |   1 +
>>>>>  drivers/soc/amlogic/meson-gx-clk-measure.c | 224 +++++++++++++++++++++++++++++
>>>>>  3 files changed, 233 insertions(+)
>>>>>  create mode 100644 drivers/soc/amlogic/meson-gx-clk-measure.c
>>>>>
>>>>> diff --git a/drivers/soc/amlogic/Kconfig b/drivers/soc/amlogic/Kconfig
>>>>> index b04f6e4..4a3217d 100644
>>>>> --- a/drivers/soc/amlogic/Kconfig
>>>>> +++ b/drivers/soc/amlogic/Kconfig
>>>>> @@ -1,5 +1,13 @@
>>>>>  menu "Amlogic SoC drivers"
>>>>>
>>>>> +config MESON_GX_CLK_MEASURE
>>>>> +       bool "Amlogic Meson GX SoC Clock Measure driver"
>>>>> +       depends on ARCH_MESON || COMPILE_TEST
>>>>> +       default ARCH_MESON
>>>>> +       help
>>>>> +         Say yes to support of Measuring a set of internal SoC clocks
>>>>> +         from the debugfs interface.
>>>>> +
>>>>>  config MESON_GX_SOCINFO
>>>>>         bool "Amlogic Meson GX SoC Information driver"
>>>>>         depends on ARCH_MESON || COMPILE_TEST
>>>>> diff --git a/drivers/soc/amlogic/Makefile b/drivers/soc/amlogic/Makefile
>>>>> index 8fa3218..a0ad966 100644
>>>>> --- a/drivers/soc/amlogic/Makefile
>>>>> +++ b/drivers/soc/amlogic/Makefile
>>>>> @@ -1,3 +1,4 @@
>>>>> +obj-$(CONFIG_MESON_GX_CLK_MEASURE) += meson-gx-clk-measure.o
>>>>>  obj-$(CONFIG_MESON_GX_SOCINFO) += meson-gx-socinfo.o
>>>>>  obj-$(CONFIG_MESON_GX_PM_DOMAINS) += meson-gx-pwrc-vpu.o
>>>>>  obj-$(CONFIG_MESON_MX_SOCINFO) += meson-mx-socinfo.o
>>>>> diff --git a/drivers/soc/amlogic/meson-gx-clk-measure.c b/drivers/soc/amlogic/meson-gx-clk-measure.c
>>>>> new file mode 100644
>>>>> index 0000000..434d9f3
>>>>> --- /dev/null
>>>>> +++ b/drivers/soc/amlogic/meson-gx-clk-measure.c
>>>
>>> [...]
>>>
>>>>> +       CLK_MSR_ID(57, "wave420l_c"),
>>>>> +       CLK_MSR_ID(58, "wave420l_b"),
>>>> AFAIK the Chips&Media WAVE420L video codec is only available on GXM (S912)
>>>> I assume reading this on GXBB or GXL simply reads 0?
>>>
>>> Yes
>>>
>>>>
>>>>> +       CLK_MSR_ID(59, "hcodec"),
>>>>> +       CLK_MSR_ID(60, "alt_32k"),
>>>>> +       CLK_MSR_ID(61, "gpio_msr"),
>>>>> +       CLK_MSR_ID(62, "hevc"),
>>>>> +       CLK_MSR_ID(66, "vid_lock"),
>>>>> +       CLK_MSR_ID(70, "pwm_f"),
>>>>> +       CLK_MSR_ID(71, "pwm_e"),
>>>>> +       CLK_MSR_ID(72, "pwm_d"),
>>>>> +       CLK_MSR_ID(73, "pwm_C"),
>>>> should this be pwm_c (instead of pwm_C)?
>>>>
>>>>> +       CLK_MSR_ID(75, "aoclkx2_int"),
>>>>> +       CLK_MSR_ID(76, "aoclk_int"),
>>>>> +       CLK_MSR_ID(77, "rng_ring_osc_0"),
>>>>> +       CLK_MSR_ID(78, "rng_ring_osc_1"),
>>>>> +       CLK_MSR_ID(79, "rng_ring_osc_2"),
>>>>> +       CLK_MSR_ID(80, "rng_ring_osc_3"),
>>>>> +       CLK_MSR_ID(81, "vapb"),
>>>>> +       CLK_MSR_ID(82, "ge2d"),
>>>>> +};
>>>> I did a quick check whether the clock IDs are really the same for all GX SoCs:
>>>> apart from clocks missing on older SoCs (see for example the WAVE420L
>>>> clocks above) there were only minor renames but no conflicts!
>>>
>>> I did the same work ! I will add this detail to the commit log.
>>> Thanks for checking ;-)
>> :)
>>
>>>>
>>>>> +
>>>>> +static int meson_gx_measure_id(struct meson_gx_msr *priv, unsigned int id)
>>>>> +{
>>>>> +       unsigned int val;
>>>>> +       int ret;
>>>>> +
>>>>> +       regmap_write(priv->regmap, MSR_CLK_REG0, 0);
>>>>> +
>>>>> +       /* Set measurement gate to 50uS */
>>>>> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_CLK_DIV,
>>>>> +                          FIELD_PREP(MSR_CLK_DIV, DIV_50US));
>>>>> +
>>>>> +       /* Set ID */
>>>>> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_CLK_SRC,
>>>>> +                          FIELD_PREP(MSR_CLK_SRC, id));
>>>>> +
>>>>> +       /* Enable & Start */
>>>>> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0,
>>>>> +                          MSR_RUN | MSR_ENABLE,
>>>>> +                          MSR_RUN | MSR_ENABLE);
>>>>> +
>>>>> +       ret = regmap_read_poll_timeout(priv->regmap, MSR_CLK_REG0,
>>>>> +                                      val, !(val & MSR_BUSY), 10, 1000);
>>>>> +       if (ret)
>>>>> +               return ret;
>>>>> +
>>>>> +       /* Disable */
>>>>> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_ENABLE, 0);
>>>>> +
>>>>> +       /* Get the value in MHz*64 */
>>>>> +       regmap_read(priv->regmap, MSR_CLK_REG2, &val);
>>>>> +
>>>>> +       return (((val + 31) & MSR_VAL_MASK) / 64) * 1000000;
>>>>> +}
>>>>> +
>>>>> +static int clk_msr_show(struct seq_file *s, void *data)
>>>>> +{
>>>>> +       struct meson_gx_msr_id *clk_msr_id = s->private;
>>>>> +       int val;
>>>>> +
>>>>> +       val = meson_gx_measure_id(clk_msr_id->priv, clk_msr_id->id);
>>>>> +       if (val < 0)
>>>>> +               return val;
>>>>> +
>>>>> +       seq_printf(s, "%d\n", val);
>>>
>>> With jerome, we managed to have a much higher precision by cycling over the divider
>>> and checking when the counter overflows. And I will print the precision in the clock debugfs
>>> entry.
>> great that you could even improve the precision!
>>
>>>>> +
>>>>> +       return 0;
>>>>> +}
>>>>> +DEFINE_SHOW_ATTRIBUTE(clk_msr);
>>>> have you considered modelling this as clock driver instead?
>>>
>>> Yes, but it can wait.
>>> Actually this clk-msr can be feed to GEN_CLK and be outputted to a pad,
>>> but all this is only for debug, so we can stick to debugfs for now.
>>>
>>> Question, should I separate the clocks in a subdirectory and add a summary file like
>>> for the clk debugfs ?
>>>
>>>
>>> /sys/kernel/debug/meson-clk-msr
>>> ------------------|--- summary
>>> ------------------|--- clks
>>> -----------------------|--- ring_osc_out_ee_0
>>> ...
>>> -----------------------|--- ge2d
>>>
>>> ?
>> this is exactly why I was curious if you considered implementing this
>> as clock driver instead
>> based on your description above each measured clock will have the
>> following properties:
>> - id (passed to the clkmsr IP block)
>> - name (human readable name)
>> - clock rate
>> - accuracy
>>
>> doesn't CCF provide everything except "id"? you'll even get the summary
>>
>> can you explain how you would use the clkmsr output?
>> here's how I would use it:
>> - assume I'm debugging something broken
>> - I suspect that it may be due to the clock setup
>> - grep "suspicious-clock" /sys/kernel/debug/clk/clk_summary
>> - compare the grep output with /sys/kernel/debug/meson-clk-msr/suspicious-clock
>>
>> if it was a CCF driver I could simply do:
>> grep "suspicious-clock" /sys/kernel/debug/clk/clk_summary
>> -> this would return "suspicious-clock" (which is what the kernel can
>> configure) and "clkmsr_suspicious-clock" (which is what clkmsr reads)

I'm concerned because it will add a bunch of duplicate clock that will be measured each time you cat clk_summary...

I'm alsi concerned by the "CCF clock provider" feature, meaning we could feed the CLK_GEN with the clock selected
by the clk-msr, but this mean we won't be able to change the measured clock at will, only the CCF will select the
clock to measure. and we will loose the ability to have a summary of all internal clocks from debugfs.

> 
> Even futther, Couldn't this measure IP be used by the current CCF code
> (as an additonal, optional property) such the the debugfs clk_summary
> uses it directly?

It will need hacking the CCF core, but as Jerome and I said, this can be done later on !
We can push a debugfs version and migrate it to CCF when we figure out how to integrate it
correctly.

> 
> Kevin
> 
Neil
Martin Blumenstingl July 14, 2018, 2:41 p.m. UTC | #5
Hi Neil,

On Wed, Jul 11, 2018 at 10:37 AM Neil Armstrong <narmstrong@baylibre.com> wrote:
>
> On 09/07/2018 23:41, Kevin Hilman wrote:
> > Martin Blumenstingl <martin.blumenstingl@googlemail.com> writes:
> >
> >> Hi Neil,
> >>
> >> On Wed, Jul 4, 2018 at 10:41 AM Neil Armstrong <narmstrong@baylibre.com> wrote:
> >>>
> >>> Hi Martin,
> >>>
> >>> On 03/07/2018 21:18, Martin Blumenstingl wrote:
> >>>> Hi Neil,
> >>>>
> >>>> On Tue, Jul 3, 2018 at 3:23 PM Neil Armstrong <narmstrong@baylibre.com> wrote:
> >>>>>
> >>>>> The Amlogic Meson GX SoCs embeds a clock measurer IP to measure the internal
> >>>>> clock paths frequencies.
> >>>>> The precision is in the order of the MHz.
> >>>>>
> >>>>> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
> >>>>> ---
> >>>>>  drivers/soc/amlogic/Kconfig                |   8 ++
> >>>>>  drivers/soc/amlogic/Makefile               |   1 +
> >>>>>  drivers/soc/amlogic/meson-gx-clk-measure.c | 224 +++++++++++++++++++++++++++++
> >>>>>  3 files changed, 233 insertions(+)
> >>>>>  create mode 100644 drivers/soc/amlogic/meson-gx-clk-measure.c
> >>>>>
> >>>>> diff --git a/drivers/soc/amlogic/Kconfig b/drivers/soc/amlogic/Kconfig
> >>>>> index b04f6e4..4a3217d 100644
> >>>>> --- a/drivers/soc/amlogic/Kconfig
> >>>>> +++ b/drivers/soc/amlogic/Kconfig
> >>>>> @@ -1,5 +1,13 @@
> >>>>>  menu "Amlogic SoC drivers"
> >>>>>
> >>>>> +config MESON_GX_CLK_MEASURE
> >>>>> +       bool "Amlogic Meson GX SoC Clock Measure driver"
> >>>>> +       depends on ARCH_MESON || COMPILE_TEST
> >>>>> +       default ARCH_MESON
> >>>>> +       help
> >>>>> +         Say yes to support of Measuring a set of internal SoC clocks
> >>>>> +         from the debugfs interface.
> >>>>> +
> >>>>>  config MESON_GX_SOCINFO
> >>>>>         bool "Amlogic Meson GX SoC Information driver"
> >>>>>         depends on ARCH_MESON || COMPILE_TEST
> >>>>> diff --git a/drivers/soc/amlogic/Makefile b/drivers/soc/amlogic/Makefile
> >>>>> index 8fa3218..a0ad966 100644
> >>>>> --- a/drivers/soc/amlogic/Makefile
> >>>>> +++ b/drivers/soc/amlogic/Makefile
> >>>>> @@ -1,3 +1,4 @@
> >>>>> +obj-$(CONFIG_MESON_GX_CLK_MEASURE) += meson-gx-clk-measure.o
> >>>>>  obj-$(CONFIG_MESON_GX_SOCINFO) += meson-gx-socinfo.o
> >>>>>  obj-$(CONFIG_MESON_GX_PM_DOMAINS) += meson-gx-pwrc-vpu.o
> >>>>>  obj-$(CONFIG_MESON_MX_SOCINFO) += meson-mx-socinfo.o
> >>>>> diff --git a/drivers/soc/amlogic/meson-gx-clk-measure.c b/drivers/soc/amlogic/meson-gx-clk-measure.c
> >>>>> new file mode 100644
> >>>>> index 0000000..434d9f3
> >>>>> --- /dev/null
> >>>>> +++ b/drivers/soc/amlogic/meson-gx-clk-measure.c
> >>>
> >>> [...]
> >>>
> >>>>> +       CLK_MSR_ID(57, "wave420l_c"),
> >>>>> +       CLK_MSR_ID(58, "wave420l_b"),
> >>>> AFAIK the Chips&Media WAVE420L video codec is only available on GXM (S912)
> >>>> I assume reading this on GXBB or GXL simply reads 0?
> >>>
> >>> Yes
> >>>
> >>>>
> >>>>> +       CLK_MSR_ID(59, "hcodec"),
> >>>>> +       CLK_MSR_ID(60, "alt_32k"),
> >>>>> +       CLK_MSR_ID(61, "gpio_msr"),
> >>>>> +       CLK_MSR_ID(62, "hevc"),
> >>>>> +       CLK_MSR_ID(66, "vid_lock"),
> >>>>> +       CLK_MSR_ID(70, "pwm_f"),
> >>>>> +       CLK_MSR_ID(71, "pwm_e"),
> >>>>> +       CLK_MSR_ID(72, "pwm_d"),
> >>>>> +       CLK_MSR_ID(73, "pwm_C"),
> >>>> should this be pwm_c (instead of pwm_C)?
> >>>>
> >>>>> +       CLK_MSR_ID(75, "aoclkx2_int"),
> >>>>> +       CLK_MSR_ID(76, "aoclk_int"),
> >>>>> +       CLK_MSR_ID(77, "rng_ring_osc_0"),
> >>>>> +       CLK_MSR_ID(78, "rng_ring_osc_1"),
> >>>>> +       CLK_MSR_ID(79, "rng_ring_osc_2"),
> >>>>> +       CLK_MSR_ID(80, "rng_ring_osc_3"),
> >>>>> +       CLK_MSR_ID(81, "vapb"),
> >>>>> +       CLK_MSR_ID(82, "ge2d"),
> >>>>> +};
> >>>> I did a quick check whether the clock IDs are really the same for all GX SoCs:
> >>>> apart from clocks missing on older SoCs (see for example the WAVE420L
> >>>> clocks above) there were only minor renames but no conflicts!
> >>>
> >>> I did the same work ! I will add this detail to the commit log.
> >>> Thanks for checking ;-)
> >> :)
> >>
> >>>>
> >>>>> +
> >>>>> +static int meson_gx_measure_id(struct meson_gx_msr *priv, unsigned int id)
> >>>>> +{
> >>>>> +       unsigned int val;
> >>>>> +       int ret;
> >>>>> +
> >>>>> +       regmap_write(priv->regmap, MSR_CLK_REG0, 0);
> >>>>> +
> >>>>> +       /* Set measurement gate to 50uS */
> >>>>> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_CLK_DIV,
> >>>>> +                          FIELD_PREP(MSR_CLK_DIV, DIV_50US));
> >>>>> +
> >>>>> +       /* Set ID */
> >>>>> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_CLK_SRC,
> >>>>> +                          FIELD_PREP(MSR_CLK_SRC, id));
> >>>>> +
> >>>>> +       /* Enable & Start */
> >>>>> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0,
> >>>>> +                          MSR_RUN | MSR_ENABLE,
> >>>>> +                          MSR_RUN | MSR_ENABLE);
> >>>>> +
> >>>>> +       ret = regmap_read_poll_timeout(priv->regmap, MSR_CLK_REG0,
> >>>>> +                                      val, !(val & MSR_BUSY), 10, 1000);
> >>>>> +       if (ret)
> >>>>> +               return ret;
> >>>>> +
> >>>>> +       /* Disable */
> >>>>> +       regmap_update_bits(priv->regmap, MSR_CLK_REG0, MSR_ENABLE, 0);
> >>>>> +
> >>>>> +       /* Get the value in MHz*64 */
> >>>>> +       regmap_read(priv->regmap, MSR_CLK_REG2, &val);
> >>>>> +
> >>>>> +       return (((val + 31) & MSR_VAL_MASK) / 64) * 1000000;
> >>>>> +}
> >>>>> +
> >>>>> +static int clk_msr_show(struct seq_file *s, void *data)
> >>>>> +{
> >>>>> +       struct meson_gx_msr_id *clk_msr_id = s->private;
> >>>>> +       int val;
> >>>>> +
> >>>>> +       val = meson_gx_measure_id(clk_msr_id->priv, clk_msr_id->id);
> >>>>> +       if (val < 0)
> >>>>> +               return val;
> >>>>> +
> >>>>> +       seq_printf(s, "%d\n", val);
> >>>
> >>> With jerome, we managed to have a much higher precision by cycling over the divider
> >>> and checking when the counter overflows. And I will print the precision in the clock debugfs
> >>> entry.
> >> great that you could even improve the precision!
> >>
> >>>>> +
> >>>>> +       return 0;
> >>>>> +}
> >>>>> +DEFINE_SHOW_ATTRIBUTE(clk_msr);
> >>>> have you considered modelling this as clock driver instead?
> >>>
> >>> Yes, but it can wait.
> >>> Actually this clk-msr can be feed to GEN_CLK and be outputted to a pad,
> >>> but all this is only for debug, so we can stick to debugfs for now.
> >>>
> >>> Question, should I separate the clocks in a subdirectory and add a summary file like
> >>> for the clk debugfs ?
> >>>
> >>>
> >>> /sys/kernel/debug/meson-clk-msr
> >>> ------------------|--- summary
> >>> ------------------|--- clks
> >>> -----------------------|--- ring_osc_out_ee_0
> >>> ...
> >>> -----------------------|--- ge2d
> >>>
> >>> ?
> >> this is exactly why I was curious if you considered implementing this
> >> as clock driver instead
> >> based on your description above each measured clock will have the
> >> following properties:
> >> - id (passed to the clkmsr IP block)
> >> - name (human readable name)
> >> - clock rate
> >> - accuracy
> >>
> >> doesn't CCF provide everything except "id"? you'll even get the summary
> >>
> >> can you explain how you would use the clkmsr output?
> >> here's how I would use it:
> >> - assume I'm debugging something broken
> >> - I suspect that it may be due to the clock setup
> >> - grep "suspicious-clock" /sys/kernel/debug/clk/clk_summary
> >> - compare the grep output with /sys/kernel/debug/meson-clk-msr/suspicious-clock
> >>
> >> if it was a CCF driver I could simply do:
> >> grep "suspicious-clock" /sys/kernel/debug/clk/clk_summary
> >> -> this would return "suspicious-clock" (which is what the kernel can
> >> configure) and "clkmsr_suspicious-clock" (which is what clkmsr reads)
>
> I'm concerned because it will add a bunch of duplicate clock that will be measured each time you cat clk_summary...
>
> I'm alsi concerned by the "CCF clock provider" feature, meaning we could feed the CLK_GEN with the clock selected
> by the clk-msr, but this mean we won't be able to change the measured clock at will, only the CCF will select the
> clock to measure. and we will loose the ability to have a summary of all internal clocks from debugfs.
that is a good point. I think this applies to both, the pure debugfs
solution as well as any CCF based solution

> >
> > Even futther, Couldn't this measure IP be used by the current CCF code
> > (as an additonal, optional property) such the the debugfs clk_summary
> > uses it directly?
>
> It will need hacking the CCF core, but as Jerome and I said, this can be done later on !
> We can push a debugfs version and migrate it to CCF when we figure out how to integrate it
> correctly.
Jerome already raised concerns (on IRC) that measuring the clock takes
too much time and using a CCF clock provider would mean that "cat
/sys/kernel/debug/clk/clk_summary" would be slow
if that's the case then I'm happy with a debugfs solution which can be
migrated wo whatever framework suits best in the future


Regards
Martin
Jerome Brunet July 16, 2018, 8:41 a.m. UTC | #6
On Sat, 2018-07-14 at 16:41 +0200, Martin Blumenstingl wrote:
> > > 
> > > Even futther, Couldn't this measure IP be used by the current CCF code
> > > (as an additonal, optional property) such the the debugfs clk_summary
> > > uses it directly?
> > 
> > It will need hacking the CCF core, but as Jerome and I said, this can be done later on !
> > We can push a debugfs version and migrate it to CCF when we figure out how to integrate it
> > correctly.
> 
> Jerome already raised concerns (on IRC) that measuring the clock takes
> too much time and using a CCF clock provider would mean that "cat
> /sys/kernel/debug/clk/clk_summary" would be slow
> if that's the case then I'm happy with a debugfs solution which can be
> migrated wo whatever framework suits best in the future

Actually I'm not concerned by clk_summary much, it is debug. Slow is not
desirable but not critical either. I'm more concerned by tree recalc while
changing the tree topology and rate change if clock measure implement
get_rate(). It is worth trying ... just keep an eye ton this.
diff mbox

Patch

--- /tmp/gxl.txt	2018-07-03 21:09:35.223606980 +0200
+++ /tmp/gxm.txt	2018-07-03 21:09:44.203759074 +0200
@@ -22,9 +22,9 @@ 
 		[61] = "gpio_clk_msr       ",
 		[60] = "alt_32k_clk        ",
 		[59] = "cts_hcodec_clk     ",
-		[58] = "0                  ",
-		[57] = "0					",
-		[56] = "0					",
+		[58] = "cts_wave420l_bclk                  ",
+		[57] = "cts_wave420l_cclk	",
+		[56] = "cts_cci_clk			",
 		[55] = "vid_pll_div_clk_out	",
 		[54] = "0					",
 		[53] = "Sd_emmc_clk_A		",
@@ -56,7 +56,7 @@ 
 		[27] = "0					   ",
 		[26] = "sc_clk_int			   ",
 		[25] = "0					   ",
-		[24] = "0					   ",
+		[24] = "sys_cpu1_clk_div16			",
 		[23] = "HDMI_CLK_TODIG		   ",
 		[22] = "eth_phy_ref_clk		   ",
 		[21] = "i2s_clk_in_src0		   ",
@@ -69,7 +69,7 @@ 
 		[14] = "cts_FEC_CLK_0		   ",
 		[13] = "cts_amclk			   ",
 		[12] = "Cts_pdm_clk			   ",
-		[11] = "rgmii_tx_clk_to_phy	   ",
+		[11] = "mac_eth_tx_clk	   ",
 		[10] = "cts_vdac_clk			   ",
 		[9] = "cts_encl_clk			  ",
 		[8] = "cts_encp_clk			  ",