Hi, Lucas Best Regards! Anson Huang > -----Original Message----- > From: Lucas Stach [mailto:l.stach@xxxxxxxxxxxxxx] > Sent: 2019年2月22日 18:55 > To: Anson Huang <anson.huang@xxxxxxx>; robh+dt@xxxxxxxxxx; > mark.rutland@xxxxxxx; shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx; > kernel@xxxxxxxxxxxxxx; festevam@xxxxxxxxx; mturquette@xxxxxxxxxxxx; > sboyd@xxxxxxxxxx; Abel Vesa <abel.vesa@xxxxxxx>; ccaione@xxxxxxxxxxxx; > agx@xxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux- > clk@xxxxxxxxxxxxxxx > Cc: dl-linux-imx <linux-imx@xxxxxxx> > Subject: Re: [PATCH 1/3] clk: imx8mq: initialize clock tree earlier > > Am Freitag, den 22.02.2019, 09:42 +0000 schrieb Anson Huang: > > Currently on i.MX8MQ platform, clock driver is probed later than GPIO > > driver, and GPIO driver does NOT have defer probe mechanism since the > > GPIO clock is optional, > > So this is what should be fixed. If there is a clock reference in the DT, having > the clock driver ready is not optional. Optional to the GPIO driver just means > it won't fail if there is no clock reference at all. > If there is and the clock provider is not yet there, it needs to do a > PROBE_DEFER. > > So that's a NACK on this patch. OK, I see. Then I will do a patch for GPIO driver, and I just check other drivers, looks like imx2 watchdog driver also has similar issue, I will do a patch too. Thanks, Anson. > > Regards, > Lucas > > > some platforms have GPIO clocks and some are NOT. So it is an issue > > that on i.MX8MQ platform, there are GPIO clocks defined, but due to > > clock tree is NOT ready during GPIO driver probe, the GPIO clock > > management will fail and cause system hang if GPIO clocks are OFF by > > default. > > > > This patch changes the i.MX8MQ clock tree initialization using > > CLK_OF_DECLARE instead of platform driver model to make clock tree > > ready earlier than GPIO driver. > > > > Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx> > > --- > > drivers/clk/imx/clk-imx8mq.c | 33 +++++++-------------------------- > > 1 file changed, 7 insertions(+), 26 deletions(-) > > > > diff --git a/drivers/clk/imx/clk-imx8mq.c b/drivers/clk/imx/clk- > > imx8mq.c index 26b57f4..2df1575 100644 > > --- a/drivers/clk/imx/clk-imx8mq.c > > +++ b/drivers/clk/imx/clk-imx8mq.c > > @@ -269,10 +269,9 @@ static const char *imx8mq_clko2_sels[] = > > {"osc_25m", "sys2_pll_200m", "sys1_pll_ > > > > static struct clk_onecell_data clk_data; > > > > -static int imx8mq_clocks_probe(struct platform_device *pdev) > > +static void __init imx8mq_clocks_init(struct device_node *np) > > { > > - struct device *dev = &pdev->dev; > > - struct device_node *np = dev->of_node; > > + struct device_node *anatop_np; > > void __iomem *base; > > int err; > > int i; > > @@ -286,10 +285,10 @@ static int imx8mq_clocks_probe(struct > > platform_device *pdev) > > clks[IMX8MQ_CLK_EXT3] = of_clk_get_by_name(np, "clk_ext3"); > > clks[IMX8MQ_CLK_EXT4] = of_clk_get_by_name(np, "clk_ext4"); > > > > - np = of_find_compatible_node(NULL, NULL, "fsl,imx8mq-anatop"); > > - base = of_iomap(np, 0); > > + anatop_np = of_find_compatible_node(NULL, NULL, "fsl,imx8mq- > > anatop"); > > + base = of_iomap(anatop_np, 0); > > if (WARN_ON(!base)) > > - return -ENOMEM; > > + return; > > > > clks[IMX8MQ_ARM_PLL_REF_SEL] = imx_clk_mux("arm_pll_ref_sel", > base + > > 0x28, 16, 2, pll_ref_sels, ARRAY_SIZE(pll_ref_sels)); > > clks[IMX8MQ_GPU_PLL_REF_SEL] = imx_clk_mux("gpu_pll_ref_sel", > base + > > 0x18, 16, 2, pll_ref_sels, ARRAY_SIZE(pll_ref_sels)); @@ -389,10 > > +388,9 @@ static int imx8mq_clocks_probe(struct platform_device *pdev) > > clks[IMX8MQ_SYS2_PLL_500M] = > > imx_clk_fixed_factor("sys2_pll_500m", "sys2_pll_out", 1, 2); > > clks[IMX8MQ_SYS2_PLL_1000M] = > > imx_clk_fixed_factor("sys2_pll_1000m", "sys2_pll_out", 1, 1); > > > > - np = dev->of_node; > > base = of_iomap(np, 0); > > if (WARN_ON(!base)) > > - return -ENOMEM; > > + return; > > > > /* CORE */ > > clks[IMX8MQ_CLK_A53_SRC] = imx_clk_mux2("arm_a53_src", base + > > 0x8000, 24, 3, imx8mq_a53_sels, ARRAY_SIZE(imx8mq_a53_sels)); @@ > > -568,22 +566,5 @@ static int imx8mq_clocks_probe(struct > > platform_device *pdev) > > > > err = of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data); > > WARN_ON(err); > > - > > - return err; > > } > > - > > -static const struct of_device_id imx8mq_clk_of_match[] = { > > - { .compatible = "fsl,imx8mq-ccm" }, > > - { /* Sentinel */ }, > > -}; > > -MODULE_DEVICE_TABLE(of, imx8mq_clk_of_match); > > - > > - > > -static struct platform_driver imx8mq_clk_driver = { > > - .probe = imx8mq_clocks_probe, > > - .driver = { > > - .name = "imx8mq-ccm", > > - .of_match_table = of_match_ptr(imx8mq_clk_of_match), > > - }, > > -}; > > -module_platform_driver(imx8mq_clk_driver); > > +CLK_OF_DECLARE(imx8mq, "fsl,imx8mq-ccm", imx8mq_clocks_init);
