| Message ID | 1520373735-13699-1-git-send-email-martin@kaiser.cx (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Martin, On Tue, Mar 6, 2018 at 7:02 PM, Martin Kaiser <martin@kaiser.cx> wrote: > The ssi1_ipg clock depends on ssi1_ipg_per. Set ssi1_ipg_per as parent > clock of ssi1_ipg. Without this link, the fsl_ssi driver does not > activate the ssi1_ipg clock correctly and ssi1 is unable to transfer > audio data. > > Fix the parent clock of ssi2 as well, it shows the same behaviour. > > Signed-off-by: Martin Kaiser <martin@kaiser.cx> > --- > Dear all, > > could you have a look at this patch? This makes SSI1 and 2 work for me. I get audio working from SSI1, but I guess this is due to the fact that the bootloader enables the SSI clock: I have the following in U-Boot: /* Enable the clocks */ DATA 4 0x53f8000c 0x1fffffff DATA 4 0x53f80010 0xffffffff DATA 4 0x53f80014 0xfdfff I will try tomorrow to disable the SSI1 clock from U-Boot and apply your patch. Will let you know how my testing goes. > With the default "ipg" parent clocks, I get no ipg clocks on the SSIs. > However, I was wondering why we don't need anything similar e.g. for the > UARTs... Maybe your bootloader is already turning on the UART clocks?
Hi Fabio, Thus wrote Fabio Estevam (festevam@gmail.com): > I get audio working from SSI1, but I guess this is due to the fact > that the bootloader enables the SSI clock: > I have the following in U-Boot: > /* Enable the clocks */ > DATA 4 0x53f8000c 0x1fffffff > DATA 4 0x53f80010 0xffffffff > DATA 4 0x53f80014 0xfdfff I'm using the same initial settings. Nevertheless, ssi1_ipg_per is disbled after loading the kernel. Digging into this a bit more, it turned out that without my patch, clk_disable_unused() recognizes ssi1_ipg_per as unused and disables it. If my patch is applied and ssi1_ipg_per is declared as parent of ssi1_ipg, clk_disable_unused() will not disable it and fsl_ssi_startup() will enable both ssi1_ipg_per and ssi1_ipg before playing sound. Best regards, Martin
Hi Martin, On Thu, Mar 8, 2018 at 11:08 AM, Martin Kaiser <martin@kaiser.cx> wrote: > Hi Fabio, > > Thus wrote Fabio Estevam (festevam@gmail.com): > >> I get audio working from SSI1, but I guess this is due to the fact >> that the bootloader enables the SSI clock: > >> I have the following in U-Boot: > >> /* Enable the clocks */ >> DATA 4 0x53f8000c 0x1fffffff >> DATA 4 0x53f80010 0xffffffff >> DATA 4 0x53f80014 0xfdfff > > I'm using the same initial settings. > > Nevertheless, ssi1_ipg_per is disbled after loading the kernel. > > Digging into this a bit more, it turned out that without my patch, > clk_disable_unused() recognizes ssi1_ipg_per as unused and disables it. > > If my patch is applied and ssi1_ipg_per is declared as parent of > ssi1_ipg, clk_disable_unused() will not disable it and fsl_ssi_startup() > will enable both ssi1_ipg_per and ssi1_ipg before playing sound. I can get audio to work fine without your patch on a mx25pdk. In the other i.MX clock drivers we have this same pattern: clks[IMX6SL_CLK_SSI1_IPG] = imx_clk_gate2_shared("ssi1_ipg", "ipg", It is not clear to me what is the real issue this patch is trying to fix. Thanks
Hi Fabio, thanks for the quick response. Thus wrote Fabio Estevam (festevam@gmail.com): > Hi Martin, > On Thu, Mar 8, 2018 at 11:08 AM, Martin Kaiser <martin@kaiser.cx> wrote: > > Hi Fabio, > > Thus wrote Fabio Estevam (festevam@gmail.com): > >> I get audio working from SSI1, but I guess this is due to the fact > >> that the bootloader enables the SSI clock: > >> I have the following in U-Boot: > >> /* Enable the clocks */ > >> DATA 4 0x53f8000c 0x1fffffff > >> DATA 4 0x53f80010 0xffffffff > >> DATA 4 0x53f80014 0xfdfff > > I'm using the same initial settings. > > Nevertheless, ssi1_ipg_per is disbled after loading the kernel. > > Digging into this a bit more, it turned out that without my patch, > > clk_disable_unused() recognizes ssi1_ipg_per as unused and disables it. > > If my patch is applied and ssi1_ipg_per is declared as parent of > > ssi1_ipg, clk_disable_unused() will not disable it and fsl_ssi_startup() > > will enable both ssi1_ipg_per and ssi1_ipg before playing sound. > I can get audio to work fine without your patch on a mx25pdk. this is surprising. How come the ssi1_ipg_per clock is not turned off by clk_disable_unused()? Where is it used? Do you have <&clks 55> anywhere in your DT? > In the other i.MX clock drivers we have this same pattern: > clks[IMX6SL_CLK_SSI1_IPG] = imx_clk_gate2_shared("ssi1_ipg", "ipg", It seems to the that imx25 uses a different clock hierarchy for ssi than other imx chips. Documentation/devicetree/bindings/clock/imx25-clock.txt: ssi1_ipg_per 55 Documentation/devicetree/bindings/clock/imx25-clock.txt: ssi2_ipg_per 56 Documentation/devicetree/bindings/clock/imx25-clock.txt: ssi1_ipg 117 Documentation/devicetree/bindings/clock/imx25-clock.txt: ssi2_ipg 118 Documentation/devicetree/bindings/clock/imx31-clock.txt: ssi1_gate 32 Documentation/devicetree/bindings/clock/imx31-clock.txt: ssi2_gate 52 Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi_sel 22 Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi1_div_pre 23 Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi1_div_post 24 Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi2_div_pre 25 Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi2_div_post 26 Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi1_gate 68 Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi2_gate 69 Others don't have ssiX_ipg_per. > It is not clear to me what is the real issue this patch is trying to fix. True. This needs clarification. I found that, in oder to get a tx clock out of the SSI, both ssi1_ipg_per and ssi1_ipg clocks must be active. The fsl_ssi driver only activates ssi1_ipg. If I activate ssi1_ipg_per in the bootloader, clk_disable_unused() deactivates it. (My codec chip does not use a dedicated clock line. It takes the bit clock that is the output of SSI. Are you maybe using ssi1_ipg_per for your codec and enable it there?) In my first mail, I was wondering about imx25 uart1, where we also have uart1_ipg and uart_ipg_per and the clock seeting is clk[uart1_ipg] = imx_clk_gate("uart1_ipg", "ipg", ccm(CCM_CGCR2), 14); In this case, both uart1 and uart_ipg_per are listed in the device tree uart1: serial@43f90000 { ... clocks = <&clks 120>, <&clks 57>; clock-names = "ipg", "per"; }; Documentation/devicetree/bindings/clock/imx25-clock.txt uart_ipg_per 57 uart1_ipg 120 and the driver enables both clocks explicitly. So they are not unused. Doing something like this is not an option for ssi, this will not work with imx31, 35 etc. Therefore, I suggest setting ssi1_ipg_per as parent of ssi1_ipg. Best regards, Martin
Hi, On Thu, 8 Mar 2018 17:46:54 +0100 Martin Kaiser wrote: > Hi Fabio, > > thanks for the quick response. > > Thus wrote Fabio Estevam (festevam@gmail.com): > > > Hi Martin, > > > On Thu, Mar 8, 2018 at 11:08 AM, Martin Kaiser <martin@kaiser.cx> wrote: > > > Hi Fabio, > > > > Thus wrote Fabio Estevam (festevam@gmail.com): > > > >> I get audio working from SSI1, but I guess this is due to the fact > > >> that the bootloader enables the SSI clock: > > > >> I have the following in U-Boot: > > > >> /* Enable the clocks */ > > >> DATA 4 0x53f8000c 0x1fffffff > > >> DATA 4 0x53f80010 0xffffffff > > >> DATA 4 0x53f80014 0xfdfff > > > > I'm using the same initial settings. > > > > Nevertheless, ssi1_ipg_per is disbled after loading the kernel. > > > > Digging into this a bit more, it turned out that without my patch, > > > clk_disable_unused() recognizes ssi1_ipg_per as unused and disables it. > > > > If my patch is applied and ssi1_ipg_per is declared as parent of > > > ssi1_ipg, clk_disable_unused() will not disable it and fsl_ssi_startup() > > > will enable both ssi1_ipg_per and ssi1_ipg before playing sound. > > > I can get audio to work fine without your patch on a mx25pdk. > > this is surprising. How come the ssi1_ipg_per clock is not turned off by > clk_disable_unused()? Where is it used? Do you have > > <&clks 55> > > anywhere in your DT? > > > In the other i.MX clock drivers we have this same pattern: > > > clks[IMX6SL_CLK_SSI1_IPG] = imx_clk_gate2_shared("ssi1_ipg", "ipg", > > It seems to the that imx25 uses a different clock hierarchy for ssi than other > imx chips. > > Documentation/devicetree/bindings/clock/imx25-clock.txt: ssi1_ipg_per 55 > Documentation/devicetree/bindings/clock/imx25-clock.txt: ssi2_ipg_per 56 > Documentation/devicetree/bindings/clock/imx25-clock.txt: ssi1_ipg 117 > Documentation/devicetree/bindings/clock/imx25-clock.txt: ssi2_ipg 118 > Documentation/devicetree/bindings/clock/imx31-clock.txt: ssi1_gate 32 > Documentation/devicetree/bindings/clock/imx31-clock.txt: ssi2_gate 52 > Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi_sel 22 > Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi1_div_pre 23 > Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi1_div_post 24 > Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi2_div_pre 25 > Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi2_div_post 26 > Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi1_gate 68 > Documentation/devicetree/bindings/clock/imx35-clock.txt: ssi2_gate 69 > > Others don't have ssiX_ipg_per. > > > It is not clear to me what is the real issue this patch is trying to fix. > > True. This needs clarification. > > I found that, in oder to get a tx clock out of the SSI, both ssi1_ipg_per and > ssi1_ipg clocks must be active. > > The fsl_ssi driver only activates ssi1_ipg. > > If I activate ssi1_ipg_per in the bootloader, clk_disable_unused() deactivates it. > > (My codec chip does not use a dedicated clock line. It takes the bit clock that > is the output of SSI. Are you maybe using ssi1_ipg_per for your codec and > enable it there?) > > In my first mail, I was wondering about imx25 uart1, where we also have > uart1_ipg and uart_ipg_per and the clock seeting is > > clk[uart1_ipg] = imx_clk_gate("uart1_ipg", "ipg", ccm(CCM_CGCR2), 14); > > In this case, both uart1 and uart_ipg_per are listed in the device tree > > uart1: serial@43f90000 { > ... > clocks = <&clks 120>, <&clks 57>; > clock-names = "ipg", "per"; > }; > > Documentation/devicetree/bindings/clock/imx25-clock.txt > uart_ipg_per 57 > uart1_ipg 120 > > and the driver enables both clocks explicitly. So they are not unused. > > > Doing something like this is not an option for ssi, this will not work with > imx31, 35 etc. > > Therefore, I suggest setting ssi1_ipg_per as parent of ssi1_ipg. > The right wayto fix this is to add the missing ipg_per clock to the DTB rather than introducing a bogus clock relationship that doesn't exist in hardware. The sound/soc/fsl/fsl_ssi.c driver does already handle a second clock as bitclock. It only needs to be specified in the DTB: &ssi1 { clocks = <&clks 117>, <&clk 55>; clock-names = "ipg", "baud"; }; Lothar Waßmann
Hi Martin, On Thu, Mar 8, 2018 at 1:46 PM, Martin Kaiser <martin@kaiser.cx> wrote: >> I can get audio to work fine without your patch on a mx25pdk. > > this is surprising. How come the ssi1_ipg_per clock is not turned off by > clk_disable_unused()? Where is it used? Do you have > > <&clks 55> > > anywhere in your DT? No, I don't. imx25-pdk board operates SSI in slave mode. > (My codec chip does not use a dedicated clock line. It takes the bit clock that > is the output of SSI. Are you maybe using ssi1_ipg_per for your codec and > enable it there?) The difference between our boards is that you use SSI in master mode and mx25pdk in slave mode. > In my first mail, I was wondering about imx25 uart1, where we also have > uart1_ipg and uart_ipg_per and the clock seeting is > > clk[uart1_ipg] = imx_clk_gate("uart1_ipg", "ipg", ccm(CCM_CGCR2), 14); > > In this case, both uart1 and uart_ipg_per are listed in the device tree > > uart1: serial@43f90000 { > ... > clocks = <&clks 120>, <&clks 57>; > clock-names = "ipg", "per"; > }; > > Documentation/devicetree/bindings/clock/imx25-clock.txt > uart_ipg_per 57 > uart1_ipg 120 > > and the driver enables both clocks explicitly. So they are not unused. > > > Doing something like this is not an option for ssi, this will not work with > imx31, 35 etc. The solution to this is passing the "baud" clock as Lothar pointed out.
Hi Fabio & Lothar, Thus wrote Fabio Estevam (festevam@gmail.com): > On Thu, Mar 8, 2018 at 1:46 PM, Martin Kaiser <martin@kaiser.cx> wrote: > >> I can get audio to work fine without your patch on a mx25pdk. > > this is surprising. How come the ssi1_ipg_per clock is not turned off by > > clk_disable_unused()? Where is it used? Do you have > > <&clks 55> > > anywhere in your DT? > No, I don't. imx25-pdk board operates SSI in slave mode. > > (My codec chip does not use a dedicated clock line. It takes the bit clock that > > is the output of SSI. Are you maybe using ssi1_ipg_per for your codec and > > enable it there?) > The difference between our boards is that you use SSI in master mode > and mx25pdk in slave mode. > > In my first mail, I was wondering about imx25 uart1, where we also have > > uart1_ipg and uart_ipg_per and the clock seeting is > > clk[uart1_ipg] = imx_clk_gate("uart1_ipg", "ipg", ccm(CCM_CGCR2), 14); > > In this case, both uart1 and uart_ipg_per are listed in the device tree > > uart1: serial@43f90000 { > > ... > > clocks = <&clks 120>, <&clks 57>; > > clock-names = "ipg", "per"; > > }; > > Documentation/devicetree/bindings/clock/imx25-clock.txt > > uart_ipg_per 57 > > uart1_ipg 120 > > and the driver enables both clocks explicitly. So they are not unused. > > Doing something like this is not an option for ssi, this will not work with > > imx31, 35 etc. > The solution to this is passing the "baud" clock as Lothar pointed out. ok, I got your point now. The ssi1_ipg clock does not depend on ssi1_ipg_per. This is in line with the clock generation scheme in the reference manual. And there's configurations where ssi1_ipg should be switched on, but not ssi1_ipg_per. I'll look into using the baud clock on my board. Thanks to both of you for taking the time to explain this. Best regards, Martin
diff --git a/drivers/clk/imx/clk-imx25.c b/drivers/clk/imx/clk-imx25.c index 23686f7..ee2852f 100644 --- a/drivers/clk/imx/clk-imx25.c +++ b/drivers/clk/imx/clk-imx25.c @@ -217,8 +217,8 @@ static int __init __mx25_clocks_init(void __iomem *ccm_base) clk[sim2_ipg] = imx_clk_gate("sim2_ipg", "ipg", ccm(CCM_CGCR2), 8); clk[slcdc_ipg] = imx_clk_gate("slcdc_ipg", "ipg", ccm(CCM_CGCR2), 9); clk[spba_ipg] = imx_clk_gate("spba_ipg", "ipg", ccm(CCM_CGCR2), 10); - clk[ssi1_ipg] = imx_clk_gate("ssi1_ipg", "ipg", ccm(CCM_CGCR2), 11); - clk[ssi2_ipg] = imx_clk_gate("ssi2_ipg", "ipg", ccm(CCM_CGCR2), 12); + clk[ssi1_ipg] = imx_clk_gate("ssi1_ipg", "ssi1_ipg_per", ccm(CCM_CGCR2), 11); + clk[ssi2_ipg] = imx_clk_gate("ssi2_ipg", "ssi2_ipg_per", ccm(CCM_CGCR2), 12); clk[tsc_ipg] = imx_clk_gate("tsc_ipg", "ipg", ccm(CCM_CGCR2), 13); clk[uart1_ipg] = imx_clk_gate("uart1_ipg", "ipg", ccm(CCM_CGCR2), 14); clk[uart2_ipg] = imx_clk_gate("uart2_ipg", "ipg", ccm(CCM_CGCR2), 15);
The ssi1_ipg clock depends on ssi1_ipg_per. Set ssi1_ipg_per as parent clock of ssi1_ipg. Without this link, the fsl_ssi driver does not activate the ssi1_ipg clock correctly and ssi1 is unable to transfer audio data. Fix the parent clock of ssi2 as well, it shows the same behaviour. Signed-off-by: Martin Kaiser <martin@kaiser.cx> --- Dear all, could you have a look at this patch? This makes SSI1 and 2 work for me. With the default "ipg" parent clocks, I get no ipg clocks on the SSIs. However, I was wondering why we don't need anything similar e.g. for the UARTs... Best regards, Martin drivers/clk/imx/clk-imx25.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)