From: Anson Huang <b20788@freescale.com> To: shawn.guo@freescale.com, kernel@pengutronix.de Cc: devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH 3/3] ARM: imx: source gpt per clk from OSC for system timer Date: Wed, 3 Sep 2014 15:36:45 +0800 [thread overview] Message-ID: <1409729805-9741-4-git-send-email-b20788@freescale.com> (raw) In-Reply-To: <1409729805-9741-1-git-send-email-b20788@freescale.com> On i.MX6Q TO > 1.0, i.MX6DL and i.MX6SX, gpt per clock can be from OSC instead of ipg_per, as ipg_per's rate may be scaled when system enter low bus mode, to keep system timer NOT drift, better to make gpt per clock at fixed rate, here add support for gpt per clock to be from OSC which is at fixed rate always. There are some difference on this implementation of gpt per clock source, see below for details: i.MX6Q TO > 1.0: GPT_CR_CLKSRC, 3b'101 selects fix clock of OSC / 8 for gpt per clk; i.MX6DL and i.MX6SX: GPT_CR_CLKSRC, 3b'101 selects OSC for gpt per clk, and we must enable GPT_CR_24MEM to enable OSC clk source for gpt per, GPT_PR_PRESCALER24M is for pre-scaling of this OSC clk, here set it to 8 to make gpt per clk is 3MHz; i.MX6SL: ipg_per can be from OSC directly, so no need to implement this new clk source for gpt per. Signed-off-by: Anson Huang <b20788@freescale.com> --- arch/arm/mach-imx/time.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/arch/arm/mach-imx/time.c b/arch/arm/mach-imx/time.c index bf92e5a..54d23c7 100644 --- a/arch/arm/mach-imx/time.c +++ b/arch/arm/mach-imx/time.c @@ -60,11 +60,15 @@ #define MX2_TSTAT_CAPT (1 << 1) #define MX2_TSTAT_COMP (1 << 0) -/* MX31, MX35, MX25, MX5 */ +/* MX31, MX35, MX25, MX5, MX6 */ #define V2_TCTL_WAITEN (1 << 3) /* Wait enable mode */ #define V2_TCTL_CLK_IPG (1 << 6) #define V2_TCTL_CLK_PER (2 << 6) +#define V2_TCTL_CLK_OSC_DIV8 (5 << 6) +#define V2_TCTL_CLK_OSC (7 << 6) #define V2_TCTL_FRR (1 << 9) +#define V2_TCTL_24MEN (1 << 10) +#define V2_TPRER_PRE24M 12 #define V2_IR 0x0c #define V2_TSTAT 0x08 #define V2_TSTAT_OF1 (1 << 0) @@ -293,7 +297,7 @@ static int __init mxc_clockevent_init(struct clk *timer_clk) static void __init _mxc_timer_init(int irq, struct clk *clk_per, struct clk *clk_ipg) { - uint32_t tctl_val; + uint32_t tctl_val, tprer_val; if (IS_ERR(clk_per)) { pr_err("i.MX timer: unable to get clk\n"); @@ -312,10 +316,25 @@ static void __init _mxc_timer_init(int irq, __raw_writel(0, timer_base + MXC_TCTL); __raw_writel(0, timer_base + MXC_TPRER); /* see datasheet note */ - if (timer_is_v2()) - tctl_val = V2_TCTL_CLK_PER | V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN; - else + if (timer_is_v2()) { + if ((cpu_is_imx6q() && imx_get_soc_revision() > + IMX_CHIP_REVISION_1_0) || cpu_is_imx6dl() || + cpu_is_imx6sx()) { + tctl_val = V2_TCTL_CLK_OSC_DIV8 | V2_TCTL_FRR | + V2_TCTL_WAITEN | MXC_TCTL_TEN; + if (cpu_is_imx6dl() || cpu_is_imx6sx()) { + /* 24 / 8 = 3 MHz */ + tprer_val = 7 << V2_TPRER_PRE24M; + __raw_writel(tprer_val, timer_base + MXC_TPRER); + tctl_val |= V2_TCTL_24MEN; + } + } else { + tctl_val = V2_TCTL_CLK_PER | V2_TCTL_FRR | + V2_TCTL_WAITEN | MXC_TCTL_TEN; + } + } else { tctl_val = MX1_2_TCTL_FRR | MX1_2_TCTL_CLK_PCLK1 | MXC_TCTL_TEN; + } __raw_writel(tctl_val, timer_base + MXC_TCTL); -- 1.7.9.5
WARNING: multiple messages have this Message-ID (diff)
From: b20788@freescale.com (Anson Huang) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 3/3] ARM: imx: source gpt per clk from OSC for system timer Date: Wed, 3 Sep 2014 15:36:45 +0800 [thread overview] Message-ID: <1409729805-9741-4-git-send-email-b20788@freescale.com> (raw) In-Reply-To: <1409729805-9741-1-git-send-email-b20788@freescale.com> On i.MX6Q TO > 1.0, i.MX6DL and i.MX6SX, gpt per clock can be from OSC instead of ipg_per, as ipg_per's rate may be scaled when system enter low bus mode, to keep system timer NOT drift, better to make gpt per clock at fixed rate, here add support for gpt per clock to be from OSC which is at fixed rate always. There are some difference on this implementation of gpt per clock source, see below for details: i.MX6Q TO > 1.0: GPT_CR_CLKSRC, 3b'101 selects fix clock of OSC / 8 for gpt per clk; i.MX6DL and i.MX6SX: GPT_CR_CLKSRC, 3b'101 selects OSC for gpt per clk, and we must enable GPT_CR_24MEM to enable OSC clk source for gpt per, GPT_PR_PRESCALER24M is for pre-scaling of this OSC clk, here set it to 8 to make gpt per clk is 3MHz; i.MX6SL: ipg_per can be from OSC directly, so no need to implement this new clk source for gpt per. Signed-off-by: Anson Huang <b20788@freescale.com> --- arch/arm/mach-imx/time.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/arch/arm/mach-imx/time.c b/arch/arm/mach-imx/time.c index bf92e5a..54d23c7 100644 --- a/arch/arm/mach-imx/time.c +++ b/arch/arm/mach-imx/time.c @@ -60,11 +60,15 @@ #define MX2_TSTAT_CAPT (1 << 1) #define MX2_TSTAT_COMP (1 << 0) -/* MX31, MX35, MX25, MX5 */ +/* MX31, MX35, MX25, MX5, MX6 */ #define V2_TCTL_WAITEN (1 << 3) /* Wait enable mode */ #define V2_TCTL_CLK_IPG (1 << 6) #define V2_TCTL_CLK_PER (2 << 6) +#define V2_TCTL_CLK_OSC_DIV8 (5 << 6) +#define V2_TCTL_CLK_OSC (7 << 6) #define V2_TCTL_FRR (1 << 9) +#define V2_TCTL_24MEN (1 << 10) +#define V2_TPRER_PRE24M 12 #define V2_IR 0x0c #define V2_TSTAT 0x08 #define V2_TSTAT_OF1 (1 << 0) @@ -293,7 +297,7 @@ static int __init mxc_clockevent_init(struct clk *timer_clk) static void __init _mxc_timer_init(int irq, struct clk *clk_per, struct clk *clk_ipg) { - uint32_t tctl_val; + uint32_t tctl_val, tprer_val; if (IS_ERR(clk_per)) { pr_err("i.MX timer: unable to get clk\n"); @@ -312,10 +316,25 @@ static void __init _mxc_timer_init(int irq, __raw_writel(0, timer_base + MXC_TCTL); __raw_writel(0, timer_base + MXC_TPRER); /* see datasheet note */ - if (timer_is_v2()) - tctl_val = V2_TCTL_CLK_PER | V2_TCTL_FRR | V2_TCTL_WAITEN | MXC_TCTL_TEN; - else + if (timer_is_v2()) { + if ((cpu_is_imx6q() && imx_get_soc_revision() > + IMX_CHIP_REVISION_1_0) || cpu_is_imx6dl() || + cpu_is_imx6sx()) { + tctl_val = V2_TCTL_CLK_OSC_DIV8 | V2_TCTL_FRR | + V2_TCTL_WAITEN | MXC_TCTL_TEN; + if (cpu_is_imx6dl() || cpu_is_imx6sx()) { + /* 24 / 8 = 3 MHz */ + tprer_val = 7 << V2_TPRER_PRE24M; + __raw_writel(tprer_val, timer_base + MXC_TPRER); + tctl_val |= V2_TCTL_24MEN; + } + } else { + tctl_val = V2_TCTL_CLK_PER | V2_TCTL_FRR | + V2_TCTL_WAITEN | MXC_TCTL_TEN; + } + } else { tctl_val = MX1_2_TCTL_FRR | MX1_2_TCTL_CLK_PCLK1 | MXC_TCTL_TEN; + } __raw_writel(tctl_val, timer_base + MXC_TCTL); -- 1.7.9.5
next prev parent reply other threads:[~2014-09-03 7:36 UTC|newest] Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-09-03 7:36 [PATCH 0/3] move gpt per clk parent for ipg_per to OSC Anson Huang 2014-09-03 7:36 ` Anson Huang 2014-09-03 7:36 ` Anson Huang [this message] 2014-09-03 7:36 ` [PATCH 3/3] ARM: imx: source gpt per clk from OSC for system timer Anson Huang [not found] ` <1409729805-9741-1-git-send-email-b20788-KZfg59tc24xl57MIdRCFDg@public.gmane.org> 2014-09-03 7:36 ` [PATCH 1/3] ARM: imx: add gpt_3m clk for i.mx6qdl Anson Huang 2014-09-03 7:36 ` Anson Huang 2014-09-03 7:36 ` [PATCH 2/3] ARM: dts: imx6: change gpt per clk to gpt_3m on i.mx6qdl and i.mx6sx Anson Huang 2014-09-03 7:36 ` Anson Huang 2014-09-04 3:56 ` [PATCH 0/3] move gpt per clk parent for ipg_per to OSC Shawn Guo 2014-09-04 3:56 ` Shawn Guo 2014-09-04 22:50 ` Fabio Estevam 2014-09-04 22:50 ` Fabio Estevam [not found] ` <CAOMZO5BOfsvrH3ijxKwyGemEW-B60n-+4wpDZ5xfC98efM469w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> 2014-09-04 23:37 ` Anson.Huang-KZfg59tc24xl57MIdRCFDg 2014-09-04 23:37 ` Anson.Huang at freescale.com [not found] ` <9B0C19C6-6C3B-47DC-9DC4-5BD42CE294A4-KZfg59tc24xl57MIdRCFDg@public.gmane.org> 2014-09-04 23:42 ` Fabio Estevam 2014-09-04 23:42 ` Fabio Estevam 2014-09-05 0:35 ` Shawn Guo 2014-09-05 0:35 ` Shawn Guo 2014-09-05 3:32 ` Anson.Huang 2014-09-05 3:32 ` Anson.Huang at freescale.com
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