Hi Bo Shen, Thank you for your review.
> -----Original Message----- > From: Bo Shen [mailto:[email protected]] > Sent: 2015年10月28日 11:14 > To: Yang, Wenyou > Cc: U-Boot Mailing List; [email protected] > Subject: Re: [PATCH v2] arm: at91: clock: Add the generated clock support > > Hi Wenyou, > > On 10/26/2015 11:31 AM, Wenyou Yang wrote: > > Some peripherals may need a second clock source that may be different > > from the system clock. This second clock is the generated clock (GCK) > > and is managed by the PMC via PMC_PCR. > > > > For simplicity, the clock source of the GCK is fixed to PLLA_CLK. > > > > Signed-off-by: Wenyou Yang <[email protected]> > > --- > > Hi Andreas, Bo Shen, > > > > Thank you for your so many advices. > > Bo Shen, sorry for forgetting version 2 to send for your comments. > > It's OK, don't worry. > > At that time the datasheet is not available, now it is available now. > So, add one more comment. > > > Please help review, thank you in advance. > > > > Best Regards, > > Wenyou Yang > > > > Changes in v2: > > 1./ add timeout to wait for GCK ready. > > 2./ add warning for timeout to wait for GCK ready. > > 3./ add printout when the improper GCK clock source is selected. > > 4./ rework AT91_PMC_PCR_GCKDIV_(x) macro to make sure x is right. > > > > arch/arm/mach-at91/armv7/clock.c | 65 > ++++++++++++++++++++++++++++ > > arch/arm/mach-at91/include/mach/at91_pmc.h | 13 ++++++ > > arch/arm/mach-at91/include/mach/clk.h | 3 ++ > > 3 files changed, 81 insertions(+) > > > > diff --git a/arch/arm/mach-at91/armv7/clock.c > > b/arch/arm/mach-at91/armv7/clock.c > > index 0bf453e..de95d6b 100644 > > --- a/arch/arm/mach-at91/armv7/clock.c > > +++ b/arch/arm/mach-at91/armv7/clock.c > > @@ -5,6 +5,7 @@ > > * Copyright (C) 2005 Ivan Kokshaysky > > * Copyright (C) 2009 Jean-Christophe PLAGNIOL-VILLARD > <[email protected]> > > * Copyright (C) 2013 Bo Shen <[email protected]> > > + * Copyright (C) 2015 Wenyou Yang <[email protected]> > > * > > * SPDX-License-Identifier: GPL-2.0+ > > */ > > @@ -173,3 +174,67 @@ void at91_periph_clk_disable(int id) > > > > writel(regval, &pmc->pcr); > > } > > + > > +void at91_enable_periph_generated_clk(u32 id) { > > + struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC; > > + u32 regval, status; > > + u32 timeout = 1000; > > + > > + if (id > AT91_PMC_PCR_PID_MASK) > > + return; > > + > > + writel(id, &pmc->pcr); > > + regval = readl(&pmc->pcr); > > + regval &= ~AT91_PMC_PCR_GCKCSS; > > + regval &= ~AT91_PMC_PCR_GCKDIV; > > + regval |= AT91_PMC_PCR_GCKCSS_PLLA_CLK | > > + AT91_PMC_PCR_CMD_WRITE | > > + AT91_PMC_PCR_GCKDIV_(1) | > > + AT91_PMC_PCR_GCKEN; > > You hard code the GCKCSS and GCKDIV. Would it be OK for all peripheral which > need this kind of clock? Can you make it as a parameter? As you know, our use-case is not complex, it is only used for one or two peripherals for now, So to make it simple, use hard-code. Maybe we will improve it in the future, but now it is enough. Anyway, thank you for your advice. > > > + > > + writel(regval, &pmc->pcr); > > + > > + do { > > + udelay(1); > > + status = readl(&pmc->sr); > > + } while ((!!(--timeout)) && (!(status & AT91_PMC_GCKRDY))); > > + > > + if (!timeout) > > + printf("Timeout waiting for GCK ready!\n"); } > > + > > +u32 at91_get_periph_generated_clk(u32 id) { > > + struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC; > > + u32 regval, clk_source, div; > > + u32 freq; > > + > > + if (id > AT91_PMC_PCR_PID_MASK) > > + return 0; > > + > > + writel(id, &pmc->pcr); > > + regval = readl(&pmc->pcr); > > + > > + clk_source = regval & AT91_PMC_PCR_GCKCSS; > > + switch (clk_source) { > > + case AT91_PMC_PCR_GCKCSS_SLOW_CLK: > > + freq = CONFIG_SYS_AT91_SLOW_CLOCK; > > + break; > > + case AT91_PMC_PCR_GCKCSS_MAIN_CLK: > > + freq = gd->arch.main_clk_rate_hz; > > + break; > > + case AT91_PMC_PCR_GCKCSS_PLLA_CLK: > > + freq = gd->arch.plla_rate_hz; > > + break; > > + default: > > + printf("Improper GCK clock source selection!\n"); > > + freq = 0; > > + break; > > + } > > + > > + div = ((regval & AT91_PMC_PCR_GCKDIV) >> > AT91_PMC_PCR_GCKDIV_OFFSET); > > + div += 1; > > + > > + return freq / div; > > +} > > diff --git a/arch/arm/mach-at91/include/mach/at91_pmc.h > > b/arch/arm/mach-at91/include/mach/at91_pmc.h > > index 8a3fb94..5a51be6 100644 > > --- a/arch/arm/mach-at91/include/mach/at91_pmc.h > > +++ b/arch/arm/mach-at91/include/mach/at91_pmc.h > > @@ -153,8 +153,20 @@ typedef struct at91_pmc { > > #define AT91_PMC_IXR_MOSCSELS 0x00010000 > > > > #define AT91_PMC_PCR_PID_MASK (0x3f) > > +#define AT91_PMC_PCR_GCKCSS (0x7 << 8) > > +#define AT91_PMC_PCR_GCKCSS_SLOW_CLK (0x0 << 8) > > +#define AT91_PMC_PCR_GCKCSS_MAIN_CLK (0x1 << 8) > > +#define AT91_PMC_PCR_GCKCSS_PLLA_CLK (0x2 << 8) > > +#define AT91_PMC_PCR_GCKCSS_UPLL_CLK (0x3 << 8) > > +#define AT91_PMC_PCR_GCKCSS_MCK_CLK (0x4 << 8) > > +#define AT91_PMC_PCR_GCKCSS_AUDIO_CLK (0x5 << 8) > > #define AT91_PMC_PCR_CMD_WRITE (0x1 << 12) > > +#define AT91_PMC_PCR_DIV (0x3 << 16) > > +#define AT91_PMC_PCR_GCKDIV (0xff << 20) > > +#define AT91_PMC_PCR_GCKDIV_(x) ((x & 0xff) << 20) > > +#define AT91_PMC_PCR_GCKDIV_OFFSET 20 > > #define AT91_PMC_PCR_EN (0x1 << 28) > > +#define AT91_PMC_PCR_GCKEN (0x1 << 29) > > > > #define AT91_PMC_PCK (1 << 0) /* > Processor Clock */ > > #define AT91RM9200_PMC_UDP (1 << 1) /* > USB Devcice Port Clock [AT91RM9200 only] */ > > @@ -236,6 +248,7 @@ typedef struct at91_pmc { > > #define AT91_PMC_PCK1RDY (1 << 9) /* > Programmable Clock 1 */ > > #define AT91_PMC_PCK2RDY (1 << 10) /* > Programmable Clock 2 */ > > #define AT91_PMC_PCK3RDY (1 << 11) /* > Programmable Clock 3 */ > > +#define AT91_PMC_GCKRDY (1 << 24) > > > > #define AT91_PMC_PROTKEY 0x504d4301 /* Activation > > Code > */ > > #endif > > diff --git a/arch/arm/mach-at91/include/mach/clk.h > > b/arch/arm/mach-at91/include/mach/clk.h > > index 1d45e2d..dd1ed96 100644 > > --- a/arch/arm/mach-at91/include/mach/clk.h > > +++ b/arch/arm/mach-at91/include/mach/clk.h > > @@ -119,4 +119,7 @@ static inline unsigned long get_pit_clk_rate(void) > > int at91_clock_init(unsigned long main_clock); > > void at91_periph_clk_enable(int id); > > void at91_periph_clk_disable(int id); > > +void at91_enable_periph_generated_clk(u32 id); > > +u32 at91_get_periph_generated_clk(u32 id); > > + > > #endif /* __ASM_ARM_ARCH_CLK_H__ */ > > > > Best Regards, > Bo Shen Best Regards, Wenyou Yang _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
