Patchwork MIPS: ath79: fix CPU/DDR frequency calculation for SRIF PLLs

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Submitter Gabor Juhos
Date Sept. 8, 2012, 12:02 p.m.
Message ID <1347105741-23091-1-git-send-email-juhosg@openwrt.org>
Download mbox | patch
Permalink /patch/4324/
State Accepted
Delegated to: Ralf Baechle
Headers show

Comments

Gabor Juhos - Sept. 8, 2012, 12:02 p.m.
Besides the CPU and DDR PLLs, the CPU and DDR frequencies
can be derived from other PLLs in the SRIF block on the
AR934x SoCs. The current code does not checks if the SRIF
PLLs are used and this can lead to incorrectly calculated
CPU/DDR frequencies.

Fix it by calculating the frequencies from SRIF PLLs if
those are used on a given board.

Cc: <stable@vger.kernel.org>
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
---
This depends on the following patch:
'MIPS: ath79: use correct fractional dividers for {CPU,DDR}_PLL on AR934x'
https://patchwork.linux-mips.org/patch/4305/

 arch/mips/ath79/clock.c                        |  109 ++++++++++++++++++------
 arch/mips/include/asm/mach-ath79/ar71xx_regs.h |   23 +++++
 2 files changed, 104 insertions(+), 28 deletions(-)
root - Sept. 23, 2012, 5:48 p.m.
On Sat, Sep 08, 2012 at 02:02:21PM +0200, Gabor Juhos wrote:

Applied but I had to fix a conflict:

@@ -65,6 +65,8 @@
 #define AR934X_WMAC_SIZE	0x20000
 #define AR934X_EHCI_BASE	0x1b000000
 #define AR934X_EHCI_SIZE	0x200
+#define AR934X_SRIF_BASE	(AR71XX_APB_BASE + 0x00116000)
+#define AR934X_SRIF_SIZE	0x1000
 
 /*
  * DDR_CTRL block

The EHCI lines don't exist yet.  Seems harmless though.

  Ralf
Gabor Juhos - Sept. 24, 2012, 7:26 a.m.
2012.09.23. 19:48 keltezéssel, Ralf Baechle írta:
> On Sat, Sep 08, 2012 at 02:02:21PM +0200, Gabor Juhos wrote:
> 
> Applied but I had to fix a conflict:
> 
> @@ -65,6 +65,8 @@
>  #define AR934X_WMAC_SIZE	0x20000
>  #define AR934X_EHCI_BASE	0x1b000000
>  #define AR934X_EHCI_SIZE	0x200
> +#define AR934X_SRIF_BASE	(AR71XX_APB_BASE + 0x00116000)
> +#define AR934X_SRIF_SIZE	0x1000
>  
>  /*
>   * DDR_CTRL block
> 
> The EHCI lines don't exist yet.  Seems harmless though.

Hm, I'm sure that the line was present a few days ago. It has been added by the
following commit:

commit 00ffed582fe8a3f7556593c0e8baaf3da3df85b0
Author: Gabor Juhos <juhosg@openwrt.org>
Date:   Sat Aug 4 15:03:56 2012 +0000

    MIPS: ath79: add USB platform setup code for AR934X

    Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
    Patchwork: http://patchwork.linux-mips.org/patch/4172/
    Signed-off-by: John Crispin <blogic@openwrt.org>

However I don't see that commit in the 'mips-for-linux-next' branch of the
'upstream-sfr.git' tree anymore.

Also these changes are missing:
 MIPS: ath79: register USB host controller on the DB120 board
 MIPS: ath79: use a helper function for USB resource initialization

-Gabor

Patch

diff --git a/arch/mips/ath79/clock.c b/arch/mips/ath79/clock.c
index d272857..579f452 100644
--- a/arch/mips/ath79/clock.c
+++ b/arch/mips/ath79/clock.c
@@ -17,6 +17,8 @@ 
 #include <linux/err.h>
 #include <linux/clk.h>
 
+#include <asm/div64.h>
+
 #include <asm/mach-ath79/ath79.h>
 #include <asm/mach-ath79/ar71xx_regs.h>
 #include "common.h"
@@ -166,11 +168,34 @@  static void __init ar933x_clocks_init(void)
 	ath79_uart_clk.rate = ath79_ref_clk.rate;
 }
 
+static u32 __init ar934x_get_pll_freq(u32 ref, u32 ref_div, u32 nint, u32 nfrac,
+				      u32 frac, u32 out_div)
+{
+	u64 t;
+	u32 ret;
+
+	t = ath79_ref_clk.rate;
+	t *= nint;
+	do_div(t, ref_div);
+	ret = t;
+
+	t = ath79_ref_clk.rate;
+	t *= nfrac;
+	do_div(t, ref_div * frac);
+	ret += t;
+
+	ret /= (1 << out_div);
+	return ret;
+}
+
 static void __init ar934x_clocks_init(void)
 {
-	u32 pll, out_div, ref_div, nint, frac, clk_ctrl, postdiv;
+	u32 pll, out_div, ref_div, nint, nfrac, frac, clk_ctrl, postdiv;
 	u32 cpu_pll, ddr_pll;
 	u32 bootstrap;
+	void __iomem *dpll_base;
+
+	dpll_base = ioremap(AR934X_SRIF_BASE, AR934X_SRIF_SIZE);
 
 	bootstrap = ath79_reset_rr(AR934X_RESET_REG_BOOTSTRAP);
 	if (bootstrap &	AR934X_BOOTSTRAP_REF_CLK_40)
@@ -178,33 +203,59 @@  static void __init ar934x_clocks_init(void)
 	else
 		ath79_ref_clk.rate = 25 * 1000 * 1000;
 
-	pll = ath79_pll_rr(AR934X_PLL_CPU_CONFIG_REG);
-	out_div = (pll >> AR934X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
-		  AR934X_PLL_CPU_CONFIG_OUTDIV_MASK;
-	ref_div = (pll >> AR934X_PLL_CPU_CONFIG_REFDIV_SHIFT) &
-		  AR934X_PLL_CPU_CONFIG_REFDIV_MASK;
-	nint = (pll >> AR934X_PLL_CPU_CONFIG_NINT_SHIFT) &
-	       AR934X_PLL_CPU_CONFIG_NINT_MASK;
-	frac = (pll >> AR934X_PLL_CPU_CONFIG_NFRAC_SHIFT) &
-	       AR934X_PLL_CPU_CONFIG_NFRAC_MASK;
-
-	cpu_pll = nint * ath79_ref_clk.rate / ref_div;
-	cpu_pll += frac * ath79_ref_clk.rate / (ref_div * (1 << 6));
-	cpu_pll /= (1 << out_div);
-
-	pll = ath79_pll_rr(AR934X_PLL_DDR_CONFIG_REG);
-	out_div = (pll >> AR934X_PLL_DDR_CONFIG_OUTDIV_SHIFT) &
-		  AR934X_PLL_DDR_CONFIG_OUTDIV_MASK;
-	ref_div = (pll >> AR934X_PLL_DDR_CONFIG_REFDIV_SHIFT) &
-		  AR934X_PLL_DDR_CONFIG_REFDIV_MASK;
-	nint = (pll >> AR934X_PLL_DDR_CONFIG_NINT_SHIFT) &
-	       AR934X_PLL_DDR_CONFIG_NINT_MASK;
-	frac = (pll >> AR934X_PLL_DDR_CONFIG_NFRAC_SHIFT) &
-	       AR934X_PLL_DDR_CONFIG_NFRAC_MASK;
-
-	ddr_pll = nint * ath79_ref_clk.rate / ref_div;
-	ddr_pll += frac * ath79_ref_clk.rate / (ref_div * (1 << 10));
-	ddr_pll /= (1 << out_div);
+	pll = __raw_readl(dpll_base + AR934X_SRIF_CPU_DPLL2_REG);
+	if (pll & AR934X_SRIF_DPLL2_LOCAL_PLL) {
+		out_div = (pll >> AR934X_SRIF_DPLL2_OUTDIV_SHIFT) &
+			  AR934X_SRIF_DPLL2_OUTDIV_MASK;
+		pll = __raw_readl(dpll_base + AR934X_SRIF_CPU_DPLL1_REG);
+		nint = (pll >> AR934X_SRIF_DPLL1_NINT_SHIFT) &
+		       AR934X_SRIF_DPLL1_NINT_MASK;
+		nfrac = pll & AR934X_SRIF_DPLL1_NFRAC_MASK;
+		ref_div = (pll >> AR934X_SRIF_DPLL1_REFDIV_SHIFT) &
+			  AR934X_SRIF_DPLL1_REFDIV_MASK;
+		frac = 1 << 18;
+	} else {
+		pll = ath79_pll_rr(AR934X_PLL_CPU_CONFIG_REG);
+		out_div = (pll >> AR934X_PLL_CPU_CONFIG_OUTDIV_SHIFT) &
+			AR934X_PLL_CPU_CONFIG_OUTDIV_MASK;
+		ref_div = (pll >> AR934X_PLL_CPU_CONFIG_REFDIV_SHIFT) &
+			  AR934X_PLL_CPU_CONFIG_REFDIV_MASK;
+		nint = (pll >> AR934X_PLL_CPU_CONFIG_NINT_SHIFT) &
+		       AR934X_PLL_CPU_CONFIG_NINT_MASK;
+		nfrac = (pll >> AR934X_PLL_CPU_CONFIG_NFRAC_SHIFT) &
+			AR934X_PLL_CPU_CONFIG_NFRAC_MASK;
+		frac = 1 << 6;
+	}
+
+	cpu_pll = ar934x_get_pll_freq(ath79_ref_clk.rate, ref_div, nint,
+				      nfrac, frac, out_div);
+
+	pll = __raw_readl(dpll_base + AR934X_SRIF_DDR_DPLL2_REG);
+	if (pll & AR934X_SRIF_DPLL2_LOCAL_PLL) {
+		out_div = (pll >> AR934X_SRIF_DPLL2_OUTDIV_SHIFT) &
+			  AR934X_SRIF_DPLL2_OUTDIV_MASK;
+		pll = __raw_readl(dpll_base + AR934X_SRIF_DDR_DPLL1_REG);
+		nint = (pll >> AR934X_SRIF_DPLL1_NINT_SHIFT) &
+		       AR934X_SRIF_DPLL1_NINT_MASK;
+		nfrac = pll & AR934X_SRIF_DPLL1_NFRAC_MASK;
+		ref_div = (pll >> AR934X_SRIF_DPLL1_REFDIV_SHIFT) &
+			  AR934X_SRIF_DPLL1_REFDIV_MASK;
+		frac = 1 << 18;
+	} else {
+		pll = ath79_pll_rr(AR934X_PLL_DDR_CONFIG_REG);
+		out_div = (pll >> AR934X_PLL_DDR_CONFIG_OUTDIV_SHIFT) &
+			  AR934X_PLL_DDR_CONFIG_OUTDIV_MASK;
+		ref_div = (pll >> AR934X_PLL_DDR_CONFIG_REFDIV_SHIFT) &
+			   AR934X_PLL_DDR_CONFIG_REFDIV_MASK;
+		nint = (pll >> AR934X_PLL_DDR_CONFIG_NINT_SHIFT) &
+		       AR934X_PLL_DDR_CONFIG_NINT_MASK;
+		nfrac = (pll >> AR934X_PLL_DDR_CONFIG_NFRAC_SHIFT) &
+			AR934X_PLL_DDR_CONFIG_NFRAC_MASK;
+		frac = 1 << 10;
+	}
+
+	ddr_pll = ar934x_get_pll_freq(ath79_ref_clk.rate, ref_div, nint,
+				      nfrac, frac, out_div);
 
 	clk_ctrl = ath79_pll_rr(AR934X_PLL_CPU_DDR_CLK_CTRL_REG);
 
@@ -240,6 +291,8 @@  static void __init ar934x_clocks_init(void)
 
 	ath79_wdt_clk.rate = ath79_ref_clk.rate;
 	ath79_uart_clk.rate = ath79_ref_clk.rate;
+
+	iounmap(dpll_base);
 }
 
 void __init ath79_clocks_init(void)
diff --git a/arch/mips/include/asm/mach-ath79/ar71xx_regs.h b/arch/mips/include/asm/mach-ath79/ar71xx_regs.h
index 3ccae12..a5e0f17 100644
--- a/arch/mips/include/asm/mach-ath79/ar71xx_regs.h
+++ b/arch/mips/include/asm/mach-ath79/ar71xx_regs.h
@@ -65,6 +65,8 @@ 
 #define AR934X_WMAC_SIZE	0x20000
 #define AR934X_EHCI_BASE	0x1b000000
 #define AR934X_EHCI_SIZE	0x200
+#define AR934X_SRIF_BASE	(AR71XX_APB_BASE + 0x00116000)
+#define AR934X_SRIF_SIZE	0x1000
 
 /*
  * DDR_CTRL block
@@ -406,4 +408,25 @@ 
 #define AR933X_GPIO_COUNT		30
 #define AR934X_GPIO_COUNT		23
 
+/*
+ * SRIF block
+ */
+#define AR934X_SRIF_CPU_DPLL1_REG	0x1c0
+#define AR934X_SRIF_CPU_DPLL2_REG	0x1c4
+#define AR934X_SRIF_CPU_DPLL3_REG	0x1c8
+
+#define AR934X_SRIF_DDR_DPLL1_REG	0x240
+#define AR934X_SRIF_DDR_DPLL2_REG	0x244
+#define AR934X_SRIF_DDR_DPLL3_REG	0x248
+
+#define AR934X_SRIF_DPLL1_REFDIV_SHIFT	27
+#define AR934X_SRIF_DPLL1_REFDIV_MASK	0x1f
+#define AR934X_SRIF_DPLL1_NINT_SHIFT	18
+#define AR934X_SRIF_DPLL1_NINT_MASK	0x1ff
+#define AR934X_SRIF_DPLL1_NFRAC_MASK	0x0003ffff
+
+#define AR934X_SRIF_DPLL2_LOCAL_PLL	BIT(30)
+#define AR934X_SRIF_DPLL2_OUTDIV_SHIFT	13
+#define AR934X_SRIF_DPLL2_OUTDIV_MASK	0x7
+
 #endif /* __ASM_MACH_AR71XX_REGS_H */