Messages in this thread Patch in this message | | | Date | Wed, 12 Feb 2020 21:43:12 +0800 | From | Shawn Guo <> | Subject | Re: [PATCH V2 1/4] clk: imx: imx8mq: fix a53 cpu clock |
| |
On Tue, Jan 14, 2020 at 07:27:15AM +0000, Peng Fan wrote: > From: Peng Fan <peng.fan@nxp.com>
The 'imx: ' in subject is not really needed. 'clk: imx8mq: ' should be already clear enough.
> > The A53 CCM clk root only accepts input up to 1GHz, CCM A53 root > signoff timing is 1Ghz,
Is this restriction mentioned in any document?
> however the A53 core which sources from CCM > root could run above 1GHz which voilates the CCM.
s/voilates/violates
> > There is a CORE_SEL slice before A53 core, we need configure the
s/need/need to
> CORE_SEL slice source from ARM PLL, not A53 CCM clk root. > > The A53 CCM clk root should only be used when need to change ARM PLL > frequency. > > Add arm_a53_core clk that could source from arm_a53_div and arm_pll_out. > Configure a53 ccm root sources from 800MHz sys pll > Configure a53 core sources from arm_pll_out > Mark arm_a53_core as critical clock > > Fixes: db27e40b27f1 ("clk: imx8mq: Add the missing ARM clock")
We have been running this for quite a while with OPPs above 1GHz. Why didn't we hear any issue report?
Shawn
> Reviewed-by: Jacky Bai <ping.bai@nxp.com> > Signed-off-by: Peng Fan <peng.fan@nxp.com> > --- > > V2: > None > > drivers/clk/imx/clk-imx8mq.c | 16 ++++++++++++---- > include/dt-bindings/clock/imx8mq-clock.h | 4 +++- > 2 files changed, 15 insertions(+), 5 deletions(-) > > diff --git a/drivers/clk/imx/clk-imx8mq.c b/drivers/clk/imx/clk-imx8mq.c > index b031183ff427..82a16b8e98a9 100644 > --- a/drivers/clk/imx/clk-imx8mq.c > +++ b/drivers/clk/imx/clk-imx8mq.c > @@ -41,6 +41,8 @@ static const char * const video2_pll_out_sels[] = {"video2_pll1_ref_sel", }; > static const char * const imx8mq_a53_sels[] = {"osc_25m", "arm_pll_out", "sys2_pll_500m", "sys2_pll_1000m", > "sys1_pll_800m", "sys1_pll_400m", "audio_pll1_out", "sys3_pll_out", }; > > +static const char * const imx8mq_a53_core_sels[] = {"arm_a53_div", "arm_pll_out", }; > + > static const char * const imx8mq_arm_m4_sels[] = {"osc_25m", "sys2_pll_200m", "sys2_pll_250m", "sys1_pll_266m", > "sys1_pll_800m", "audio_pll1_out", "video_pll1_out", "sys3_pll_out", }; > > @@ -411,6 +413,9 @@ static int imx8mq_clocks_probe(struct platform_device *pdev) > hws[IMX8MQ_CLK_GPU_CORE_DIV] = imx8m_clk_hw_composite_core("gpu_core_div", imx8mq_gpu_core_sels, base + 0x8180); > hws[IMX8MQ_CLK_GPU_SHADER_DIV] = imx8m_clk_hw_composite("gpu_shader_div", imx8mq_gpu_shader_sels, base + 0x8200); > > + /* CORE SEL */ > + hws[IMX8MQ_CLK_A53_CORE] = imx_clk_hw_mux2_flags("arm_a53_core", base + 0x9880, 24, 1, imx8mq_a53_core_sels, ARRAY_SIZE(imx8mq_a53_core_sels), CLK_IS_CRITICAL); > + > /* BUS */ > hws[IMX8MQ_CLK_MAIN_AXI] = imx8m_clk_hw_composite_critical("main_axi", imx8mq_main_axi_sels, base + 0x8800); > hws[IMX8MQ_CLK_ENET_AXI] = imx8m_clk_hw_composite("enet_axi", imx8mq_enet_axi_sels, base + 0x8880); > @@ -574,11 +579,14 @@ static int imx8mq_clocks_probe(struct platform_device *pdev) > hws[IMX8MQ_GPT_3M_CLK] = imx_clk_hw_fixed_factor("gpt_3m", "osc_25m", 1, 8); > hws[IMX8MQ_CLK_DRAM_ALT_ROOT] = imx_clk_hw_fixed_factor("dram_alt_root", "dram_alt", 1, 4); > > - hws[IMX8MQ_CLK_ARM] = imx_clk_hw_cpu("arm", "arm_a53_div", > - hws[IMX8MQ_CLK_A53_DIV]->clk, > - hws[IMX8MQ_CLK_A53_SRC]->clk, > + clk_hw_set_parent(hws[IMX8MQ_CLK_A53_SRC], hws[IMX8MQ_SYS1_PLL_800M]); > + clk_hw_set_parent(hws[IMX8MQ_CLK_A53_CORE], hws[IMX8MQ_ARM_PLL_OUT]); > + > + hws[IMX8MQ_CLK_ARM] = imx_clk_hw_cpu("arm", "arm_a53_core", > + hws[IMX8MQ_CLK_A53_CORE]->clk, > + hws[IMX8MQ_CLK_A53_CORE]->clk, > hws[IMX8MQ_ARM_PLL_OUT]->clk, > - hws[IMX8MQ_SYS1_PLL_800M]->clk); > + hws[IMX8MQ_CLK_A53_DIV]->clk); > > imx_check_clk_hws(hws, IMX8MQ_CLK_END); > > diff --git a/include/dt-bindings/clock/imx8mq-clock.h b/include/dt-bindings/clock/imx8mq-clock.h > index 3bab9b21c8d7..ac71e9e502b8 100644 > --- a/include/dt-bindings/clock/imx8mq-clock.h > +++ b/include/dt-bindings/clock/imx8mq-clock.h > @@ -424,6 +424,8 @@ > #define IMX8MQ_SYS2_PLL_500M_CG 283 > #define IMX8MQ_SYS2_PLL_1000M_CG 284 > > -#define IMX8MQ_CLK_END 285 > +#define IMX8MQ_CLK_A53_CORE 285 > + > +#define IMX8MQ_CLK_END 286 > > #endif /* __DT_BINDINGS_CLOCK_IMX8MQ_H */ > -- > 2.16.4 >
| |