Re: [PATCH v12 6/6] clk: meson: a1: add Amlogic A1 Peripherals clock controller driver

From: Dmitry Rokosov
Date: Wed Apr 05 2023 - 10:55:28 EST


On Wed, Apr 05, 2023 at 04:13:44PM +0200, Jerome Brunet wrote:
>
> On Tue 04 Apr 2023 at 18:53, Dmitry Rokosov <ddrokosov@xxxxxxxxxxxxxx> wrote:
>
> > +/* Array of all clocks registered by this provider */
> > +static struct clk_hw_onecell_data a1_periphs_clks = {
> > + .hws = {
> > + /* DT exposed clocks */
> > + [CLKID_FIXPLL_IN] = &fixpll_in.hw,
> > + [CLKID_USB_PHY_IN] = &usb_phy_in.hw,
> > + [CLKID_USB_CTRL_IN] = &usb_ctrl_in.hw,
> > + [CLKID_HIFIPLL_IN] = &hifipll_in.hw,
> > + [CLKID_SYSPLL_IN] = &syspll_in.hw,
> > + [CLKID_DDS_IN] = &dds_in.hw,
> > + [CLKID_SYS] = &sys.hw,
> > + [CLKID_CLKTREE] = &clktree.hw,
> > + [CLKID_RESET_CTRL] = &reset_ctrl.hw,
> > + [CLKID_ANALOG_CTRL] = &analog_ctrl.hw,
> > + [CLKID_PWR_CTRL] = &pwr_ctrl.hw,
> > + [CLKID_PAD_CTRL] = &pad_ctrl.hw,
> > + [CLKID_SYS_CTRL] = &sys_ctrl.hw,
> > + [CLKID_TEMP_SENSOR] = &temp_sensor.hw,
> > + [CLKID_AM2AXI_DIV] = &am2axi_dev.hw,
> > + [CLKID_SPICC_B] = &spicc_b.hw,
> > + [CLKID_SPICC_A] = &spicc_a.hw,
> > + [CLKID_MSR] = &msr.hw,
> > + [CLKID_AUDIO] = &audio.hw,
> > + [CLKID_JTAG_CTRL] = &jtag_ctrl.hw,
> > + [CLKID_SARADC_EN] = &saradc_en.hw,
> > + [CLKID_PWM_EF] = &pwm_ef.hw,
> > + [CLKID_PWM_CD] = &pwm_cd.hw,
> > + [CLKID_PWM_AB] = &pwm_ab.hw,
> > + [CLKID_CEC] = &cec.hw,
> > + [CLKID_I2C_S] = &i2c_s.hw,
> > + [CLKID_IR_CTRL] = &ir_ctrl.hw,
> > + [CLKID_I2C_M_D] = &i2c_m_d.hw,
> > + [CLKID_I2C_M_C] = &i2c_m_c.hw,
> > + [CLKID_I2C_M_B] = &i2c_m_b.hw,
> > + [CLKID_I2C_M_A] = &i2c_m_a.hw,
> > + [CLKID_ACODEC] = &acodec.hw,
> > + [CLKID_OTP] = &otp.hw,
> > + [CLKID_SD_EMMC_A] = &sd_emmc_a.hw,
> > + [CLKID_USB_PHY] = &usb_phy.hw,
> > + [CLKID_USB_CTRL] = &usb_ctrl.hw,
> > + [CLKID_SYS_DSPB] = &sys_dspb.hw,
> > + [CLKID_SYS_DSPA] = &sys_dspa.hw,
> > + [CLKID_DMA] = &dma.hw,
> > + [CLKID_IRQ_CTRL] = &irq_ctrl.hw,
> > + [CLKID_NIC] = &nic.hw,
> > + [CLKID_GIC] = &gic.hw,
> > + [CLKID_UART_C] = &uart_c.hw,
> > + [CLKID_UART_B] = &uart_b.hw,
> > + [CLKID_UART_A] = &uart_a.hw,
> > + [CLKID_SYS_PSRAM] = &sys_psram.hw,
> > + [CLKID_RSA] = &rsa.hw,
> > + [CLKID_CORESIGHT] = &coresight.hw,
> > + [CLKID_AM2AXI_VAD] = &am2axi_vad.hw,
> > + [CLKID_AUDIO_VAD] = &audio_vad.hw,
> > + [CLKID_AXI_DMC] = &axi_dmc.hw,
> > + [CLKID_AXI_PSRAM] = &axi_psram.hw,
> > + [CLKID_RAMB] = &ramb.hw,
> > + [CLKID_RAMA] = &rama.hw,
> > + [CLKID_AXI_SPIFC] = &axi_spifc.hw,
> > + [CLKID_AXI_NIC] = &axi_nic.hw,
> > + [CLKID_AXI_DMA] = &axi_dma.hw,
> > + [CLKID_CPU_CTRL] = &cpu_ctrl.hw,
> > + [CLKID_ROM] = &rom.hw,
> > + [CLKID_PROC_I2C] = &prod_i2c.hw,
> > + [CLKID_DSPA_EN] = &dspa_en.hw,
> > + [CLKID_DSPA_EN_NIC] = &dspa_en_nic.hw,
> > + [CLKID_DSPB_EN] = &dspb_en.hw,
> > + [CLKID_DSPB_EN_NIC] = &dspb_en_nic.hw,
> > + [CLKID_RTC] = &rtc.hw,
> > + [CLKID_CECA_32K] = &ceca_32k_out.hw,
> > + [CLKID_CECB_32K] = &cecb_32k_out.hw,
> > + [CLKID_24M] = &clk_24m.hw,
> > + [CLKID_12M] = &clk_12m.hw,
> > + [CLKID_FCLK_DIV2_DIVN] = &fclk_div2_divn.hw,
> > + [CLKID_GEN] = &gen.hw,
> > + [CLKID_SARADC] = &saradc.hw,
> > + [CLKID_PWM_A] = &pwm_a.hw,
> > + [CLKID_PWM_B] = &pwm_b.hw,
> > + [CLKID_PWM_C] = &pwm_c.hw,
> > + [CLKID_PWM_D] = &pwm_d.hw,
> > + [CLKID_PWM_E] = &pwm_e.hw,
> > + [CLKID_PWM_F] = &pwm_f.hw,
> > + [CLKID_SPICC] = &spicc.hw,
> > + [CLKID_TS] = &ts.hw,
> > + [CLKID_SPIFC] = &spifc.hw,
> > + [CLKID_USB_BUS] = &usb_bus.hw,
> > + [CLKID_SD_EMMC] = &sd_emmc.hw,
> > + [CLKID_PSRAM] = &psram.hw,
> > + [CLKID_DMC] = &dmc.hw,
> > + [CLKID_GEN_SEL] = &gen_sel.hw,
> > + [CLKID_PWM_A_SEL] = &pwm_a_sel.hw,
> > + [CLKID_PWM_B_SEL] = &pwm_b_sel.hw,
> > + [CLKID_PWM_C_SEL] = &pwm_c_sel.hw,
> > + [CLKID_PWM_D_SEL] = &pwm_d_sel.hw,
> > + [CLKID_PWM_E_SEL] = &pwm_e_sel.hw,
> > + [CLKID_PWM_F_SEL] = &pwm_f_sel.hw,
> > + [CLKID_DSPA_A_SEL] = &dspa_a_sel.hw,
> > + [CLKID_DSPA_B_SEL] = &dspa_b_sel.hw,
> > + [CLKID_DSPB_A_SEL] = &dspb_a_sel.hw,
> > + [CLKID_DSPB_B_SEL] = &dspb_b_sel.hw,
> > + [CLKID_CECA_32K_SEL] = &ceca_32k_sel.hw,
> > + [CLKID_CECA_32K_SEL_PRE] = &ceca_32k_sel_pre.hw,
> > + [CLKID_CECB_32K_SEL] = &cecb_32k_sel.hw,
> > + [CLKID_CECB_32K_SEL_PRE] = &cecb_32k_sel_pre.hw,
> > +
> > + /* Internal clocks */
>
> There is no need to make such groups within the table.
> I don't think such change was requested in the previous reviews.
>
> Also grouping the IDs the way you did is a bad idea.
>
> 1) Since the clocks are registered in the order of the table, this will
> make a lot of orphans during the registration of the controller. It does
> work but it is not ideal performance wise. Whenever possible, it is
> better to register the clocks from the roots to the leafs.
>
> 2) These 2 nice groups are going away the minute you add another clock which
> was not part of the original submission. This is why IDs have no meaning,
> no even groups.
>

In my opinion, it would be clearer to have two separate lists for 'exposed'
and 'internal' clocks. Krzysztof has previously mentioned that non-linear
IDs in the bindings are not a good solution, but I understand the argument
for improved performance. Therefore, I will change the ID order from root to
leaf nodes.

> > + [CLKID_XTAL_IN] = &xtal_in.hw,
> > + [CLKID_DSPA_SEL] = &dspa_sel.hw,
> > + [CLKID_DSPB_SEL] = &dspb_sel.hw,
> > + [CLKID_SARADC_SEL] = &saradc_sel.hw,
> > + [CLKID_SYS_A_SEL] = &sys_a_sel.hw,
> > + [CLKID_SYS_A_DIV] = &sys_a_div.hw,
> > + [CLKID_SYS_A] = &sys_a.hw,
> > + [CLKID_SYS_B_SEL] = &sys_b_sel.hw,
> > + [CLKID_SYS_B_DIV] = &sys_b_div.hw,
> > + [CLKID_SYS_B] = &sys_b.hw,
> > + [CLKID_DSPA_A_DIV] = &dspa_a_div.hw,
> > + [CLKID_DSPA_A] = &dspa_a.hw,
> > + [CLKID_DSPA_B_DIV] = &dspa_b_div.hw,
> > + [CLKID_DSPA_B] = &dspa_b.hw,
> > + [CLKID_DSPB_A_DIV] = &dspb_a_div.hw,
> > + [CLKID_DSPB_A] = &dspb_a.hw,
> > + [CLKID_DSPB_B_DIV] = &dspb_b_div.hw,
> > + [CLKID_DSPB_B] = &dspb_b.hw,
> > + [CLKID_RTC_32K_IN] = &rtc_32k_in.hw,
> > + [CLKID_RTC_32K_DIV] = &rtc_32k_div.hw,
> > + [CLKID_RTC_32K_XTAL] = &rtc_32k_xtal.hw,
> > + [CLKID_RTC_32K_SEL] = &rtc_32k_sel.hw,
> > + [CLKID_CECB_32K_IN] = &cecb_32k_in.hw,
> > + [CLKID_CECB_32K_DIV] = &cecb_32k_div.hw,
> > + [CLKID_CECA_32K_IN] = &ceca_32k_in.hw,
> > + [CLKID_CECA_32K_DIV] = &ceca_32k_div.hw,
> > + [CLKID_DIV2_PRE] = &fclk_div2_divn_pre.hw,
> > + [CLKID_24M_DIV2] = &clk_24m_div2.hw,
> > + [CLKID_GEN_DIV] = &gen_div.hw,
> > + [CLKID_SARADC_DIV] = &saradc_div.hw,
> > + [CLKID_PWM_A_DIV] = &pwm_a_div.hw,
> > + [CLKID_PWM_B_DIV] = &pwm_b_div.hw,
> > + [CLKID_PWM_C_DIV] = &pwm_c_div.hw,
> > + [CLKID_PWM_D_DIV] = &pwm_d_div.hw,
> > + [CLKID_PWM_E_DIV] = &pwm_e_div.hw,
> > + [CLKID_PWM_F_DIV] = &pwm_f_div.hw,
> > + [CLKID_SPICC_SEL] = &spicc_sel.hw,
> > + [CLKID_SPICC_DIV] = &spicc_div.hw,
> > + [CLKID_SPICC_SEL2] = &spicc_sel2.hw,
> > + [CLKID_TS_DIV] = &ts_div.hw,
> > + [CLKID_SPIFC_SEL] = &spifc_sel.hw,
> > + [CLKID_SPIFC_DIV] = &spifc_div.hw,
> > + [CLKID_SPIFC_SEL2] = &spifc_sel2.hw,
> > + [CLKID_USB_BUS_SEL] = &usb_bus_sel.hw,
> > + [CLKID_USB_BUS_DIV] = &usb_bus_div.hw,
> > + [CLKID_SD_EMMC_SEL] = &sd_emmc_sel.hw,
> > + [CLKID_SD_EMMC_DIV] = &sd_emmc_div.hw,
> > + [CLKID_SD_EMMC_SEL2] = &sd_emmc_sel2.hw,
> > + [CLKID_PSRAM_SEL] = &psram_sel.hw,
> > + [CLKID_PSRAM_DIV] = &psram_div.hw,
> > + [CLKID_PSRAM_SEL2] = &psram_sel2.hw,
> > + [CLKID_DMC_SEL] = &dmc_sel.hw,
> > + [CLKID_DMC_DIV] = &dmc_div.hw,
> > + [CLKID_DMC_SEL2] = &dmc_sel2.hw,
> > +
> > + [NR_CLKS] = NULL,
> > + },
> > + .num = NR_CLKS,
> > +};

--
Thank you,
Dmitry