From: Sylwester Nawrocki <s.nawrocki@samsung.com> To: Andi Shyti <andi.shyti@samsung.com> Cc: Andi Shyti <andi@etezian.org>, Chanwoo Choi <cw00.choi@samsung.com>, Jaehoon Chung <jh80.chung@samsung.com>, Tomasz Figa <tomasz.figa@gmail.com>, Michael Turquette <mturquette@baylibre.com>, Stephen Boyd <sboyd@codeaurora.org>, Kukjin Kim <kgene@kernel.org>, Krzysztof Kozlowski <k.kozlowski@samsung.com>, linux-samsung-soc@vger.kernel.org, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Andrzej Hajda <a.hajda@samsung.com> Subject: Re: [PATCH v3 1/2] clk: exynos5433: do not use CLK_IGNORE_UNUSED for SPI clocks Date: Mon, 04 Jul 2016 17:15:25 +0200 [thread overview] Message-ID: <577A7D8D.8070004@samsung.com> (raw) In-Reply-To: <20160704102614.GD1257@jack.zhora.eu> On 07/04/2016 12:26 PM, Andi Shyti wrote: > The single clock lines are not configured in the exynos5433 dts, > but in the drivers/clk/samsung/clk-exynos5433.c file and it's the > only place where we can set the flags. I meant we could amend which clocks are specified at the SPI bus device DT nodes and change handling of clocks in the spi-s3c64xx driver to model everything properly and get it all working. >> What is an exact problem here, are you perhaps testing suspend to RAM? >> I tested my sound support patches on top of v4.7-rc1 and everything >> seemed to work well, I didn't notice any issues with the audio codec >> which was the only slave on the SPI 1 bus. > > Yes, because the audio codec is on SPI1 and its bus line > (spi_busclk0) is CLK_SCLK_SPI1_PERIC while the CLK_SCLK_SPI1 is > set as CLK_IGNORE_UNUSED. That's true, looking at a downstream kernel I see that there is just plain div clock specified for spi_busclk0 (DIVsclk_spi1_b), i.e. SCLK_SPI1_PERIC and SCLK_SPI1 don't get disabled in s3c64xx_spi_config(). It seems SCLK_SPI1 in CMU_PERIC need to be kept enabled while accessing the SPI controller's registers. >> Doesn't it help when you specify CLK_SCLK_SPI1 as the second clock >> ("spi_busclk0") of the spi_1 bus controller instead of >> CLK_SCLK_SPI0_PERIC? CLK_SCLK_SPI0_PERIC seem to be parent of >> CLK_SCLK_SPI1 so the enable state would be propagated. > > nope! :( > > For some reasons, if you set in the DTS as spi_busclk0 the > CLK_SCLK_SPI1 from cmu_peric you get a synchronus abort in the > s3c64xx_spi_config (the first read performed on the device). Indeed, I also observed that, after removing CLK_IGNORE_UNUSED from the CLK_SCLK_SPI1 clock. After discussion with Krzysztof and Andrzej I came up with a patch as below where there is no aborts, the sound works and clocks are not kept always enabled: root@localhost:~# cat /sys/kernel/debug/clk/clk_summary | grep spi1 ioclk_spi1_clk_in 0 0 50000000 0 0 sclk_ioclk_spi1 0 0 50000000 0 0 pclk_isp_spi1 0 0 6000000 0 0 mout_sclk_isp_spi1_user 0 0 24000000 0 0 sclk_isp_spi1 0 0 24000000 0 0 mout_sclk_spi1 0 0 24000000 0 0 div_sclk_spi1_a 0 0 3000000 0 0 div_sclk_spi1_b 0 0 3000000 0 0 sclk_spi1_peric 0 0 3000000 0 0 sclk_spi1 0 0 3000000 0 0 mout_sclk_isp_spi1 0 0 24000000 0 0 div_sclk_isp_spi1_a 0 0 3000000 0 0 div_sclk_isp_spi1_b 0 0 25000 0 0 sclk_isp_spi1_cam1 0 0 25000 0 0 pclk_spi1 0 0 66666667 0 0 I'm not yet 100% sure if it is a correct approach, the downstream kernel uses "global-per-IP" gate clocks (ENABLE_IP_PERIC? registers), that gate all clocks to a given IP block and those clocks are not defined in mainline at all, but it seems we just need to amend the SPI controller driver to not be disabling sdd->src_clk clock before accessing registers. Or maybe to pass only DIVsclk_spi?_b as spi_busclk0 in DT nodes and add SCLK_SPI0 from CMU_PERIC as a third SPI device clock for exynos5433. -----------8<------------ diff --git a/arch/arm64/boot/dts/exynos/exynos5433.dtsi b/arch/arm64/boot/dts/exynos/exynos5433.dtsi index 8e124fc..f444c66 100644 --- a/arch/arm64/boot/dts/exynos/exynos5433.dtsi +++ b/arch/arm64/boot/dts/exynos/exynos5433.dtsi @@ -617,8 +617,13 @@ dma-names = "tx", "rx"; #address-cells = <1>; #size-cells = <0>; +#if 0 clocks = <&cmu_peric CLK_PCLK_SPI1>, <&cmu_top CLK_SCLK_SPI1_PERIC>; +#else + clocks = <&cmu_peric CLK_PCLK_SPI1>, + <&cmu_peric CLK_SCLK_SPI1>; +#endif clock-names = "spi", "spi_busclk0"; samsung,spi-src-clk = <0>; pinctrl-names = "default"; diff --git a/drivers/clk/samsung/clk-exynos5433.c b/drivers/clk/samsung/clk-exynos5433.c index e3cc935..61d5643 100644 --- a/drivers/clk/samsung/clk-exynos5433.c +++ b/drivers/clk/samsung/clk-exynos5433.c @@ -1675,7 +1675,7 @@ static struct samsung_gate_clock peric_gate_clks[] __initdata = { GATE(CLK_SCLK_SPI2, "sclk_spi2", "sclk_spi2_peric", ENABLE_SCLK_PERIC, 5, CLK_SET_RATE_PARENT, 0), GATE(CLK_SCLK_SPI1, "sclk_spi1", "sclk_spi1_peric", ENABLE_SCLK_PERIC, - 4, CLK_IGNORE_UNUSED | CLK_SET_RATE_PARENT, 0), + 4, CLK_SET_RATE_PARENT, 0), GATE(CLK_SCLK_SPI0, "sclk_spi0", "sclk_spi0_peric", ENABLE_SCLK_PERIC, 3, CLK_SET_RATE_PARENT, 0), GATE(CLK_SCLK_UART2, "sclk_uart2", "sclk_uart2_peric", diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 5a76a50..2cb965c 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -578,7 +578,7 @@ static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd) /* Disable Clock */ if (sdd->port_conf->clk_from_cmu) { - clk_disable_unprepare(sdd->src_clk); + /* clk_disable_unprepare(sdd->src_clk); */ } else { val = readl(regs + S3C64XX_SPI_CLK_CFG); val &= ~S3C64XX_SPI_ENCLK_ENABLE; @@ -626,7 +626,7 @@ static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd) /* There is half-multiplier before the SPI */ clk_set_rate(sdd->src_clk, sdd->cur_speed * 2); /* Enable Clock */ - clk_prepare_enable(sdd->src_clk); + /* clk_prepare_enable(sdd->src_clk); */ } else { /* Configure Clock */ val = readl(regs + S3C64XX_SPI_CLK_CFG); -----------8<------------
WARNING: multiple messages have this Message-ID (diff)
From: s.nawrocki@samsung.com (Sylwester Nawrocki) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 1/2] clk: exynos5433: do not use CLK_IGNORE_UNUSED for SPI clocks Date: Mon, 04 Jul 2016 17:15:25 +0200 [thread overview] Message-ID: <577A7D8D.8070004@samsung.com> (raw) In-Reply-To: <20160704102614.GD1257@jack.zhora.eu> On 07/04/2016 12:26 PM, Andi Shyti wrote: > The single clock lines are not configured in the exynos5433 dts, > but in the drivers/clk/samsung/clk-exynos5433.c file and it's the > only place where we can set the flags. I meant we could amend which clocks are specified at the SPI bus device DT nodes and change handling of clocks in the spi-s3c64xx driver to model everything properly and get it all working. >> What is an exact problem here, are you perhaps testing suspend to RAM? >> I tested my sound support patches on top of v4.7-rc1 and everything >> seemed to work well, I didn't notice any issues with the audio codec >> which was the only slave on the SPI 1 bus. > > Yes, because the audio codec is on SPI1 and its bus line > (spi_busclk0) is CLK_SCLK_SPI1_PERIC while the CLK_SCLK_SPI1 is > set as CLK_IGNORE_UNUSED. That's true, looking at a downstream kernel I see that there is just plain div clock specified for spi_busclk0 (DIVsclk_spi1_b), i.e. SCLK_SPI1_PERIC and SCLK_SPI1 don't get disabled in s3c64xx_spi_config(). It seems SCLK_SPI1 in CMU_PERIC need to be kept enabled while accessing the SPI controller's registers. >> Doesn't it help when you specify CLK_SCLK_SPI1 as the second clock >> ("spi_busclk0") of the spi_1 bus controller instead of >> CLK_SCLK_SPI0_PERIC? CLK_SCLK_SPI0_PERIC seem to be parent of >> CLK_SCLK_SPI1 so the enable state would be propagated. > > nope! :( > > For some reasons, if you set in the DTS as spi_busclk0 the > CLK_SCLK_SPI1 from cmu_peric you get a synchronus abort in the > s3c64xx_spi_config (the first read performed on the device). Indeed, I also observed that, after removing CLK_IGNORE_UNUSED from the CLK_SCLK_SPI1 clock. After discussion with Krzysztof and Andrzej I came up with a patch as below where there is no aborts, the sound works and clocks are not kept always enabled: root at localhost:~# cat /sys/kernel/debug/clk/clk_summary | grep spi1 ioclk_spi1_clk_in 0 0 50000000 0 0 sclk_ioclk_spi1 0 0 50000000 0 0 pclk_isp_spi1 0 0 6000000 0 0 mout_sclk_isp_spi1_user 0 0 24000000 0 0 sclk_isp_spi1 0 0 24000000 0 0 mout_sclk_spi1 0 0 24000000 0 0 div_sclk_spi1_a 0 0 3000000 0 0 div_sclk_spi1_b 0 0 3000000 0 0 sclk_spi1_peric 0 0 3000000 0 0 sclk_spi1 0 0 3000000 0 0 mout_sclk_isp_spi1 0 0 24000000 0 0 div_sclk_isp_spi1_a 0 0 3000000 0 0 div_sclk_isp_spi1_b 0 0 25000 0 0 sclk_isp_spi1_cam1 0 0 25000 0 0 pclk_spi1 0 0 66666667 0 0 I'm not yet 100% sure if it is a correct approach, the downstream kernel uses "global-per-IP" gate clocks (ENABLE_IP_PERIC? registers), that gate all clocks to a given IP block and those clocks are not defined in mainline at all, but it seems we just need to amend the SPI controller driver to not be disabling sdd->src_clk clock before accessing registers. Or maybe to pass only DIVsclk_spi?_b as spi_busclk0 in DT nodes and add SCLK_SPI0 from CMU_PERIC as a third SPI device clock for exynos5433. -----------8<------------ diff --git a/arch/arm64/boot/dts/exynos/exynos5433.dtsi b/arch/arm64/boot/dts/exynos/exynos5433.dtsi index 8e124fc..f444c66 100644 --- a/arch/arm64/boot/dts/exynos/exynos5433.dtsi +++ b/arch/arm64/boot/dts/exynos/exynos5433.dtsi @@ -617,8 +617,13 @@ dma-names = "tx", "rx"; #address-cells = <1>; #size-cells = <0>; +#if 0 clocks = <&cmu_peric CLK_PCLK_SPI1>, <&cmu_top CLK_SCLK_SPI1_PERIC>; +#else + clocks = <&cmu_peric CLK_PCLK_SPI1>, + <&cmu_peric CLK_SCLK_SPI1>; +#endif clock-names = "spi", "spi_busclk0"; samsung,spi-src-clk = <0>; pinctrl-names = "default"; diff --git a/drivers/clk/samsung/clk-exynos5433.c b/drivers/clk/samsung/clk-exynos5433.c index e3cc935..61d5643 100644 --- a/drivers/clk/samsung/clk-exynos5433.c +++ b/drivers/clk/samsung/clk-exynos5433.c @@ -1675,7 +1675,7 @@ static struct samsung_gate_clock peric_gate_clks[] __initdata = { GATE(CLK_SCLK_SPI2, "sclk_spi2", "sclk_spi2_peric", ENABLE_SCLK_PERIC, 5, CLK_SET_RATE_PARENT, 0), GATE(CLK_SCLK_SPI1, "sclk_spi1", "sclk_spi1_peric", ENABLE_SCLK_PERIC, - 4, CLK_IGNORE_UNUSED | CLK_SET_RATE_PARENT, 0), + 4, CLK_SET_RATE_PARENT, 0), GATE(CLK_SCLK_SPI0, "sclk_spi0", "sclk_spi0_peric", ENABLE_SCLK_PERIC, 3, CLK_SET_RATE_PARENT, 0), GATE(CLK_SCLK_UART2, "sclk_uart2", "sclk_uart2_peric", diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 5a76a50..2cb965c 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -578,7 +578,7 @@ static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd) /* Disable Clock */ if (sdd->port_conf->clk_from_cmu) { - clk_disable_unprepare(sdd->src_clk); + /* clk_disable_unprepare(sdd->src_clk); */ } else { val = readl(regs + S3C64XX_SPI_CLK_CFG); val &= ~S3C64XX_SPI_ENCLK_ENABLE; @@ -626,7 +626,7 @@ static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd) /* There is half-multiplier before the SPI */ clk_set_rate(sdd->src_clk, sdd->cur_speed * 2); /* Enable Clock */ - clk_prepare_enable(sdd->src_clk); + /* clk_prepare_enable(sdd->src_clk); */ } else { /* Configure Clock */ val = readl(regs + S3C64XX_SPI_CLK_CFG); -----------8<------------
next prev parent reply other threads:[~2016-07-04 15:15 UTC|newest] Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-06-30 7:15 [PATCH v3 0/2] mark spi clocks as critical and enable spi3 clocks Andi Shyti 2016-06-30 7:15 ` Andi Shyti 2016-06-30 7:15 ` Andi Shyti 2016-06-30 7:15 ` [PATCH v3 1/2] clk: exynos5433: do not use CLK_IGNORE_UNUSED for SPI clocks Andi Shyti 2016-06-30 7:15 ` Andi Shyti 2016-07-04 9:40 ` Sylwester Nawrocki 2016-07-04 9:40 ` Sylwester Nawrocki 2016-07-04 10:26 ` Andi Shyti 2016-07-04 10:26 ` Andi Shyti 2016-07-04 15:15 ` Sylwester Nawrocki [this message] 2016-07-04 15:15 ` Sylwester Nawrocki 2016-07-06 4:51 ` Andi Shyti 2016-07-06 4:51 ` Andi Shyti 2016-07-06 10:40 ` Sylwester Nawrocki 2016-07-06 10:40 ` Sylwester Nawrocki 2016-06-30 7:15 ` [PATCH v3 2/2] clk: exynos5433: enable sclk_ioclk for SPI3 Andi Shyti 2016-06-30 7:15 ` Andi Shyti 2016-06-30 7:15 ` Andi Shyti 2016-07-04 3:59 ` [PATCH v3 0/2] mark spi clocks as critical and enable spi3 clocks Tomasz Figa 2016-07-04 3:59 ` Tomasz Figa 2016-07-04 3:59 ` Tomasz Figa 2016-07-04 4:20 ` Andi Shyti 2016-07-04 4:20 ` Andi Shyti 2016-07-04 4:20 ` Andi Shyti 2016-07-04 4:55 ` Tomasz Figa 2016-07-04 4:55 ` Tomasz Figa 2016-07-04 4:55 ` Tomasz Figa
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