| Message ID | 1420559265-7333-1-git-send-email-p.zabel@pengutronix.de |
|---|---|
| State | New |
| Headers | show |
Hi Philipp, On Tue, Jan 6, 2015 at 1:47 PM, Philipp Zabel <p.zabel@pengutronix.de> wrote: > MMDC CH1 is not used on i.MX6Q, so the handshake needed to change the parent > of periph2_sel or the divider of mmdc_ch1_axi_podf will never succeed. > Disable the handshake mechanism to allow changing the frequency of mmdc_ch1_axi, > allowing to use it as a possible source for the LDB DI clock. > > Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Thanks for working on this series. It looks great. I am adding Christian on Cc as he could reproduce the bug quickly on his setup. Maybe he could give his Tested-by? On my board it takes a long time to reproduce the ldb clock lock-up issue. Thanks
Hi all > On Tue, Jan 6, 2015 at 1:47 PM, Philipp Zabel <p.zabel@pengutronix.de> wrote: >> MMDC CH1 is not used on i.MX6Q, so the handshake needed to change the parent >> of periph2_sel or the divider of mmdc_ch1_axi_podf will never succeed. >> Disable the handshake mechanism to allow changing the frequency of mmdc_ch1_axi, >> allowing to use it as a possible source for the LDB DI clock. >> >> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> > > Thanks for working on this series. It looks great. > > I am adding Christian on Cc as he could reproduce the bug quickly on > his setup. Maybe he could give his Tested-by? > I will have a look at it as I am able to reproduce this problem in less then 10 minutes. I am not sure if I find time during this week, but I try my best. greets -- Christian Gmeiner, MSc https://soundcloud.com/christian-gmeiner
diff --git a/arch/arm/mach-imx/clk-imx6q.c b/arch/arm/mach-imx/clk-imx6q.c index 5951660..f2e7cfc 100644 --- a/arch/arm/mach-imx/clk-imx6q.c +++ b/arch/arm/mach-imx/clk-imx6q.c @@ -120,6 +120,19 @@ static unsigned int share_count_ssi1; static unsigned int share_count_ssi2; static unsigned int share_count_ssi3; +#define CCM_CCDR 0x04 + +#define CCDR_MMDC_CH1_MASK BIT(16) + +static void __init imx6q_mmdc_ch1_mask_handshake(void __iomem *ccm_base) +{ + unsigned int reg; + + reg = readl_relaxed(ccm_base + CCM_CCDR); + reg |= CCDR_MMDC_CH1_MASK; + writel_relaxed(reg, ccm_base + CCM_CCDR); +} + static void __init imx6q_clocks_init(struct device_node *ccm_node) { struct device_node *np; @@ -261,6 +274,7 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node) WARN_ON(!base); imx6q_pm_set_ccm_base(base); + imx6q_mmdc_ch1_mask_handshake(base); /* name reg shift width parent_names num_parents */ clk[IMX6QDL_CLK_STEP] = imx_clk_mux("step", base + 0xc, 8, 1, step_sels, ARRAY_SIZE(step_sels));
MMDC CH1 is not used on i.MX6Q, so the handshake needed to change the parent of periph2_sel or the divider of mmdc_ch1_axi_podf will never succeed. Disable the handshake mechanism to allow changing the frequency of mmdc_ch1_axi, allowing to use it as a possible source for the LDB DI clock. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> --- arch/arm/mach-imx/clk-imx6q.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)