powerpc/mpc85xx: Add support for single source clocking

PATCH Superseded Priyanka Jain 2 participants 2 messages Dec 11, 2013 PowerPC

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Priyanka Jain

author

2013-12-11 05:13 UTC #0 lore raw

PATCH v2 1/1 powerpc/mpc85xx: Add support for single source clocking

Single-source clocking is new feature introduced in T1040. In this mode, a differential clock is supplied to the DIFF_SYSCLK_P/N inputs to the processor, which in turn is used to supply clocks to the sysclock, ddrclock and usbclock.

So, both ddrclock and syclock are driven by same differential sysclock in single-sourec clocking whereas in normal clocking mode, generally separate DDRCLK and SYSCLK pins provides reference clock for sysclock and ddrclock

DDR_REFCLK_SEL rcw bit is used to determine DDR clock source -If DDR_REFCLK_SEL rcw bit is 0, then DDR PLLs are driven in
normal clocking mode by DDR_Reference clock

-If DDR_REFCLK_SEL rcw bit is 1, then DDR PLLs are driven in
single source clocking mode by DIFF_SYSCLK

Add code to determine ddrclock based on DDR_REFCLK_SEL rcw bit.

Signed-off-by Poonam Aggrwal <[email protected]>

Signed-off-by Priyanka Jain <[email protected]>

---
Changes for v2:
Incorporated York's comment to separate out DDR_CLK_FREQ and SINGLE_SOURCE_CLK code

 arch/powerpc/cpu/mpc85xx/speed.c          |   22 ++++++++++++++++++++--
 arch/powerpc/include/asm/config_mpc85xx.h |    1 +
 arch/powerpc/include/asm/immap_85xx.h     |    3 +++
 3 files changed, 24 insertions(+), 2 deletions(-)

arch/powerpc/cpu/mpc85xx/speed.c +20 -2

index 46ae80c..ef52669 100644
@@ -76,10 +76,28 @@ void get_sys_info(sys_info_t *sys_info)
 	uint mem_pll_rat;
 
 	sys_info->freq_systembus = sysclk;
+#ifdef CONFIG_SINGLE_SOURCE_CLK
+	/*
+	 * DDR_REFCLK_SEL rcw bit is used to determine if DDR PLLS
+	 * are driven by separate DDR Refclock or single source
+	 * differential clock.
+	 */
+	uint single_src;
+	single_src = (in_be32(&gur->rcwsr[5]) >>
+		      FSL_CORENET2_RCWSR5_DDR_REFCLK_SEL_SHIFT) &
+		      FSL_CORENET2_RCWSR5_DDR_REFCLK_SEL_MASK;
+	/*
+	 * For single source clocking, both ddrclock and syclock
+	 * are driven by differential sysclock.
+	 */
+	if (single_src == FSL_CORENET2_RCWSR5_DDR_REFCLK_SINGLE_CLK)
+		sys_info->freq_ddrbus = CONFIG_SYS_CLK_FREQ;
+	else
+#endif
 #ifdef CONFIG_DDR_CLK_FREQ
-	sys_info->freq_ddrbus = CONFIG_DDR_CLK_FREQ;
+		sys_info->freq_ddrbus = CONFIG_DDR_CLK_FREQ;
 #else
-	sys_info->freq_ddrbus = sysclk;
+		sys_info->freq_ddrbus = sysclk;
 #endif
 
 	sys_info->freq_systembus *= (in_be32(&gur->rcwsr[0]) >> 25) & 0x1f;

arch/powerpc/include/asm/config_mpc85xx.h +1 -0

index 99e16bd..370bd21 100644
@@ -711,6 +711,7 @@ defined(CONFIG_PPC_T1020) || defined(CONFIG_PPC_T1022)
 #define CONFIG_FM_PLAT_CLK_DIV	1
 #define CONFIG_SYS_FM1_CLK		CONFIG_FM_PLAT_CLK_DIV
 #define CONFIG_SYS_FM_MURAM_SIZE	0x30000
+#define CONFIG_SINGLE_SOURCE_CLK
 #define CONFIG_SYS_FSL_TBCLK_DIV	32
 #define CONFIG_SYS_FSL_PCIE_COMPAT	"fsl,qoriq-pcie-v2.4"
 #define CONFIG_SYS_FSL_USB1_PHY_ENABLE

arch/powerpc/include/asm/immap_85xx.h +3 -0

index 672e8c6..68c3c82 100644
@@ -1774,6 +1774,9 @@ defined(CONFIG_PPC_T1020) || defined(CONFIG_PPC_T1022)
 #define FSL_CORENET2_RCWSR5_SRDS_PLL_PD_S3_PLL2	0x00040000
 #define FSL_CORENET2_RCWSR5_SRDS_PLL_PD_S4_PLL1	0x00020000
 #define FSL_CORENET2_RCWSR5_SRDS_PLL_PD_S4_PLL2	0x00010000
+#define FSL_CORENET2_RCWSR5_DDR_REFCLK_SEL_SHIFT 4
+#define FSL_CORENET2_RCWSR5_DDR_REFCLK_SEL_MASK	0x00000011
+#define FSL_CORENET2_RCWSR5_DDR_REFCLK_SINGLE_CLK	1
 
 #else /* CONFIG_SYS_FSL_QORIQ_CHASSIS2 */
 #define FSL_CORENET_RCWSR0_MEM_PLL_RAT_SHIFT	17

Signature · 1 line

1.7.4.1

York Sun

2013-12-11 18:11 UTC #1 lore raw

PATCH v2 1/1 powerpc/mpc85xx: Add support for single source clocking

Quoted 36 lines · Priyanka Jain

Single-source clocking is new feature introduced in T1040. In this mode, a differential clock is supplied to the DIFF_SYSCLK_P/N inputs to the processor, which in turn is used to supply clocks to the sysclock, ddrclock and usbclock.
So, both ddrclock and syclock are driven by same differential sysclock in single-sourec clocking whereas in normal clocking mode, generally separate DDRCLK and SYSCLK pins provides reference clock for sysclock and ddrclock
DDR_REFCLK_SEL rcw bit is used to determine DDR clock source
(quoted diff) +0 -2
-If DDR_REFCLK_SEL rcw bit is 0, then DDR PLLs are driven in
 normal clocking mode by DDR_Reference clock
 
-If DDR_REFCLK_SEL rcw bit is 1, then DDR PLLs are driven in
 single source clocking mode by DIFF_SYSCLK
Add code to determine ddrclock based on DDR_REFCLK_SEL rcw bit.
Signed-off-by Poonam Aggrwal <[email protected]>
Signed-off-by Priyanka Jain <[email protected]>
---
Changes for v2:
Incorporated York's comment to separate out DDR_CLK_FREQ and SINGLE_SOURCE_CLK code
 arch/powerpc/cpu/mpc85xx/speed.c          |   22 ++++++++++++++++++++--
 arch/powerpc/include/asm/config_mpc85xx.h |    1 +
 arch/powerpc/include/asm/immap_85xx.h     |    3 +++
 3 files changed, 24 insertions(+), 2 deletions(-)
arch/powerpc/cpu/mpc85xx/speed.c +0 -0
index 46ae80c..ef52669 100644

arch/powerpc/cpu/mpc85xx/speed.c void get_sys_info(sys_info_t *sys_info) · line 85

Quoted 10 lines

arch/powerpc/cpu/mpc85xx/speed.c +7 -0

@@ -76,10 +76,28 @@ void get_sys_info(sys_info_t *sys_info)
 	uint mem_pll_rat;
 
 	sys_info->freq_systembus = sysclk;
+#ifdef CONFIG_SINGLE_SOURCE_CLK
+	/*
+	 * DDR_REFCLK_SEL rcw bit is used to determine if DDR PLLS
+	 * are driven by separate DDR Refclock or single source
+	 * differential clock.
+	 */
+	uint single_src;

Sorry I missed this earlier. Please don't declare variables in the middle of a function.

York