[PATCH] clk: imx8m: fix clock tree update of TF-A managed clocks
Ahmad Fatoum
a.fatoum at pengutronix.de
Wed Aug 18 08:28:42 PDT 2021
Hello Abel,
On 18.08.21 17:14, Abel Vesa wrote:
> On 21-08-10 17:14:33, Ahmad Fatoum wrote:
>> On the i.MX8M*, the TF-A exposes a SiP (Silicon Provider) service
>> for DDR frequency scaling. The imx8m-ddrc-devfreq driver calls the
>> SiP and then does clk_set_parent on the DDR muxes to synchronize
>> the clock tree.
>>
>> Since 936c383673b9 ("clk: imx: fix composite peripheral flags"),
>> these TF-A managed muxes have SET_PARENT_GATE set, which results
>> in imx8m-ddrc-devfreq's clk_set_parent after SiP failing with -EBUSY:
>>
>> echo 25000000 > userspace/set_freq
>> imx8m-ddrc-devfreq 3d400000.memory-controller: failed to set
>> dram_apb parent: -16
>>
>> Fix this by adding a new i.MX composite flag for firmware managed
>> clocks, which clears SET_PARENT_GATE.
>>
>> This is safe to do, because updating the Linux clock tree to reflect
>> reality will always be glitch-free.
>>
>> Fixes: 936c383673b9 ("clk: imx: fix composite peripheral flags")
>> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
>
> I'm OK with this.
>
> Reviewed-by: Abel Vesa <abel.vesa at nxp.com>
Thanks for the review.
> BTW, let me know if you are interested in the interconnect+devfreq
> (the replacement for NXP's internal busfreq). I have a new version of
> that patchset which I intend to send soon for review.
Ye, add me to CC and I'll give it at least a test. It sounds like you
recently worked with devfreq? I am wondering why you didn't run into this issue.
Cheers,
Ahmad
>
>> ---
>> To: Abel Vesa <abel.vesa at nxp.com>
>> To: Michael Turquette <mturquette at baylibre.com>
>> To: Stephen Boyd <sboyd at kernel.org>
>> To: Shawn Guo <shawnguo at kernel.org>
>> To: Sascha Hauer <s.hauer at pengutronix.de>
>> To: Pengutronix Kernel Team <kernel at pengutronix.de>
>> To: Fabio Estevam <festevam at gmail.com>
>> To: NXP Linux Team <linux-imx at nxp.com>
>> To: Peng Fan <peng.fan at nxp.com>
>> To: Leonard Crestez <leonard.crestez at nxp.com>
>> Cc: linux-arm-kernel at lists.infradead.org
>> Cc: linux-kernel at vger.kernel.org
>> Cc: linux-clk at vger.kernel.org
>> ---
>> drivers/clk/imx/clk-composite-8m.c | 3 ++-
>> drivers/clk/imx/clk-imx8mm.c | 7 ++++---
>> drivers/clk/imx/clk-imx8mn.c | 7 ++++---
>> drivers/clk/imx/clk-imx8mq.c | 7 ++++---
>> drivers/clk/imx/clk.h | 16 ++++++++++++++--
>> 5 files changed, 28 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/clk/imx/clk-composite-8m.c b/drivers/clk/imx/clk-composite-8m.c
>> index 2c309e3dc8e3..04e728538cef 100644
>> --- a/drivers/clk/imx/clk-composite-8m.c
>> +++ b/drivers/clk/imx/clk-composite-8m.c
>> @@ -216,7 +216,8 @@ struct clk_hw *imx8m_clk_hw_composite_flags(const char *name,
>> div->width = PCG_PREDIV_WIDTH;
>> divider_ops = &imx8m_clk_composite_divider_ops;
>> mux_ops = &clk_mux_ops;
>> - flags |= CLK_SET_PARENT_GATE;
>> + if (!(composite_flags & IMX_COMPOSITE_FW_MANAGED))
>> + flags |= CLK_SET_PARENT_GATE;
>> }
>>
>> div->lock = &imx_ccm_lock;
>> diff --git a/drivers/clk/imx/clk-imx8mm.c b/drivers/clk/imx/clk-imx8mm.c
>> index f1919fafb124..73cc9805ec59 100644
>> --- a/drivers/clk/imx/clk-imx8mm.c
>> +++ b/drivers/clk/imx/clk-imx8mm.c
>> @@ -470,10 +470,11 @@ static int imx8mm_clocks_probe(struct platform_device *pdev)
>>
>> /*
>> * DRAM clocks are manipulated from TF-A outside clock framework.
>> - * Mark with GET_RATE_NOCACHE to always read div value from hardware
>> + * The fw_managed helper sets GET_RATE_NOCACHE and clears SET_PARENT_GATE
>> + * as div value should always be read from hardware
>> */
>> - hws[IMX8MM_CLK_DRAM_ALT] = __imx8m_clk_hw_composite("dram_alt", imx8mm_dram_alt_sels, base + 0xa000, CLK_GET_RATE_NOCACHE);
>> - hws[IMX8MM_CLK_DRAM_APB] = __imx8m_clk_hw_composite("dram_apb", imx8mm_dram_apb_sels, base + 0xa080, CLK_IS_CRITICAL | CLK_GET_RATE_NOCACHE);
>> + hws[IMX8MM_CLK_DRAM_ALT] = imx8m_clk_hw_fw_managed_composite("dram_alt", imx8mm_dram_alt_sels, base + 0xa000);
>> + hws[IMX8MM_CLK_DRAM_APB] = imx8m_clk_hw_fw_managed_composite_critical("dram_apb", imx8mm_dram_apb_sels, base + 0xa080);
>>
>> /* IP */
>> hws[IMX8MM_CLK_VPU_G1] = imx8m_clk_hw_composite("vpu_g1", imx8mm_vpu_g1_sels, base + 0xa100);
>> diff --git a/drivers/clk/imx/clk-imx8mn.c b/drivers/clk/imx/clk-imx8mn.c
>> index 88f6630cd472..0a76f969b28b 100644
>> --- a/drivers/clk/imx/clk-imx8mn.c
>> +++ b/drivers/clk/imx/clk-imx8mn.c
>> @@ -453,10 +453,11 @@ static int imx8mn_clocks_probe(struct platform_device *pdev)
>>
>> /*
>> * DRAM clocks are manipulated from TF-A outside clock framework.
>> - * Mark with GET_RATE_NOCACHE to always read div value from hardware
>> + * The fw_managed helper sets GET_RATE_NOCACHE and clears SET_PARENT_GATE
>> + * as div value should always be read from hardware
>> */
>> - hws[IMX8MN_CLK_DRAM_ALT] = __imx8m_clk_hw_composite("dram_alt", imx8mn_dram_alt_sels, base + 0xa000, CLK_GET_RATE_NOCACHE);
>> - hws[IMX8MN_CLK_DRAM_APB] = __imx8m_clk_hw_composite("dram_apb", imx8mn_dram_apb_sels, base + 0xa080, CLK_IS_CRITICAL | CLK_GET_RATE_NOCACHE);
>> + hws[IMX8MN_CLK_DRAM_ALT] = imx8m_clk_hw_fw_managed_composite("dram_alt", imx8mn_dram_alt_sels, base + 0xa000);
>> + hws[IMX8MN_CLK_DRAM_APB] = imx8m_clk_hw_fw_managed_composite_critical("dram_apb", imx8mn_dram_apb_sels, base + 0xa080);
>>
>> hws[IMX8MN_CLK_DISP_PIXEL] = imx8m_clk_hw_composite("disp_pixel", imx8mn_disp_pixel_sels, base + 0xa500);
>> hws[IMX8MN_CLK_SAI2] = imx8m_clk_hw_composite("sai2", imx8mn_sai2_sels, base + 0xa600);
>> diff --git a/drivers/clk/imx/clk-imx8mq.c b/drivers/clk/imx/clk-imx8mq.c
>> index c491bc9c61ce..83cc2b1c3294 100644
>> --- a/drivers/clk/imx/clk-imx8mq.c
>> +++ b/drivers/clk/imx/clk-imx8mq.c
>> @@ -449,11 +449,12 @@ static int imx8mq_clocks_probe(struct platform_device *pdev)
>>
>> /*
>> * DRAM clocks are manipulated from TF-A outside clock framework.
>> - * Mark with GET_RATE_NOCACHE to always read div value from hardware
>> + * The fw_managed helper sets GET_RATE_NOCACHE and clears SET_PARENT_GATE
>> + * as div value should always be read from hardware
>> */
>> hws[IMX8MQ_CLK_DRAM_CORE] = imx_clk_hw_mux2_flags("dram_core_clk", base + 0x9800, 24, 1, imx8mq_dram_core_sels, ARRAY_SIZE(imx8mq_dram_core_sels), CLK_IS_CRITICAL);
>> - hws[IMX8MQ_CLK_DRAM_ALT] = __imx8m_clk_hw_composite("dram_alt", imx8mq_dram_alt_sels, base + 0xa000, CLK_GET_RATE_NOCACHE);
>> - hws[IMX8MQ_CLK_DRAM_APB] = __imx8m_clk_hw_composite("dram_apb", imx8mq_dram_apb_sels, base + 0xa080, CLK_IS_CRITICAL | CLK_GET_RATE_NOCACHE);
>> + hws[IMX8MQ_CLK_DRAM_ALT] = imx8m_clk_hw_fw_managed_composite("dram_alt", imx8mq_dram_alt_sels, base + 0xa000);
>> + hws[IMX8MQ_CLK_DRAM_APB] = imx8m_clk_hw_fw_managed_composite_critical("dram_apb", imx8mq_dram_apb_sels, base + 0xa080);
>>
>> /* IP */
>> hws[IMX8MQ_CLK_VPU_G1] = imx8m_clk_hw_composite("vpu_g1", imx8mq_vpu_g1_sels, base + 0xa100);
>> diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h
>> index 7571603bee23..e144f983fd8c 100644
>> --- a/drivers/clk/imx/clk.h
>> +++ b/drivers/clk/imx/clk.h
>> @@ -530,8 +530,9 @@ struct clk_hw *imx_clk_hw_cpu(const char *name, const char *parent_name,
>> struct clk *div, struct clk *mux, struct clk *pll,
>> struct clk *step);
>>
>> -#define IMX_COMPOSITE_CORE BIT(0)
>> -#define IMX_COMPOSITE_BUS BIT(1)
>> +#define IMX_COMPOSITE_CORE BIT(0)
>> +#define IMX_COMPOSITE_BUS BIT(1)
>> +#define IMX_COMPOSITE_FW_MANAGED BIT(2)
>>
>> struct clk_hw *imx8m_clk_hw_composite_flags(const char *name,
>> const char * const *parent_names,
>> @@ -567,6 +568,17 @@ struct clk_hw *imx8m_clk_hw_composite_flags(const char *name,
>> ARRAY_SIZE(parent_names), reg, 0, \
>> flags | CLK_SET_RATE_NO_REPARENT | CLK_OPS_PARENT_ENABLE)
>>
>> +#define __imx8m_clk_hw_fw_managed_composite(name, parent_names, reg, flags) \
>> + imx8m_clk_hw_composite_flags(name, parent_names, \
>> + ARRAY_SIZE(parent_names), reg, IMX_COMPOSITE_FW_MANAGED, \
>> + flags | CLK_GET_RATE_NOCACHE | CLK_SET_RATE_NO_REPARENT | CLK_OPS_PARENT_ENABLE)
>> +
>> +#define imx8m_clk_hw_fw_managed_composite(name, parent_names, reg) \
>> + __imx8m_clk_hw_fw_managed_composite(name, parent_names, reg, 0)
>> +
>> +#define imx8m_clk_hw_fw_managed_composite_critical(name, parent_names, reg) \
>> + __imx8m_clk_hw_fw_managed_composite(name, parent_names, reg, CLK_IS_CRITICAL)
>> +
>> #define __imx8m_clk_composite(name, parent_names, reg, flags) \
>> to_clk(__imx8m_clk_hw_composite(name, parent_names, reg, flags))
>>
>> --
>> 2.30.2
>>
>
--
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