ARM: imx6: fix up buggy CCM_CSCMR1 register

PATCH New Shawn Guo 2 participants 5 messages Jul 10, 2013 – Jul 12, 2013

Subsystems (3)

Arm (32-bit) Arm sub-architectures Arm i.MX and Layerscape

lore

Share & tools

lore

Shawn Guo

author

2013-07-10 15:21 UTC #0 lore raw

cover ARM: imx6: fix up buggy CCM_CSCMR1 register

There is a defect in bits 22 and 21 of i.MX6 CCM_CSCMR1 register. These two bits are inverted between read and write. That said, bit field CCM_CSCMR1[22-20] (aclk/emi_podf on imx6q/dl and lcdif_pix_podf on imx6sl) will be something as below between read and write.

read write divider

   000     110       1
   001     111       2
   010     100       3
   011     101       4
   100     010       5
   101     011       6
   110     000       7
   111     001       8

To work around this hardware defect, every single read/modify/write sequence on the register will require a fix-up (invert bits 22 and 21) before writing the value into register. As there are dividers and multiplexers defined in the register, we choose to inherit the basic clk-divider and clk-mux and override the functions which writes register with a fix-up hooked in.

Shawn

Liu Ying (3):
ARM: imx: add common clock support for fixup div
ARM: imx: add common clock support for fixup mux
ARM: imx6: change some clocks to fixup clocks

 arch/arm/mach-imx/Makefile        |    3 +-
 arch/arm/mach-imx/clk-fixup-div.c |  129 +++++++++++++++++++++++++++++++++++++
 arch/arm/mach-imx/clk-fixup-mux.c |  107 ++++++++++++++++++++++++++++++
 arch/arm/mach-imx/clk-imx6q.c     |   24 +++----
 arch/arm/mach-imx/clk-imx6sl.c    |   20 +++---
 arch/arm/mach-imx/clk.c           |   26 ++++++++
 arch/arm/mach-imx/clk.h           |   10 +++
 7 files changed, 296 insertions(+), 23 deletions(-)
 create mode 100644 arch/arm/mach-imx/clk-fixup-div.c
 create mode 100644 arch/arm/mach-imx/clk-fixup-mux.c

Signature · 1 line

1.7.9.5

Shawn Guo

author

2013-07-10 15:22 UTC #1 lore raw

PATCH 1/3 ARM: imx: add common clock support for fixup div

From: Liu Ying <[email protected]>

One register may have several fields to control some clocks. It is possible that the read/write values of some fields may map to different real functional values, so writing to the other fields in the same register may break a working clock tree. A real case is the aclk_podf field in the register 'CCM Serial Clock Multiplexer Register 1' of i.MX6Q/SDL SoC. This patch introduces a fixup hook for divider clock which is called before writing a value to clock registers to support this kind of divider clocks.

Signed-off-by Liu Ying <[email protected]>

Signed-off-by Shawn Guo <[email protected]>

---
 arch/arm/mach-imx/Makefile        |    3 +-
 arch/arm/mach-imx/clk-fixup-div.c |  129 +++++++++++++++++++++++++++++++++++++
 arch/arm/mach-imx/clk.h           |    4 ++
 3 files changed, 135 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/mach-imx/clk-fixup-div.c

arch/arm/mach-imx/Makefile +2 -1

index e20f22d..92b91a2 100644
@@ -15,7 +15,8 @@ imx5-pm-$(CONFIG_PM) += pm-imx5.o
 obj-$(CONFIG_SOC_IMX5) += cpu-imx5.o mm-imx5.o clk-imx51-imx53.o ehci-imx5.o $(imx5-pm-y)
 
 obj-$(CONFIG_COMMON_CLK) += clk-pllv1.o clk-pllv2.o clk-pllv3.o clk-gate2.o \
-			    clk-pfd.o clk-busy.o clk.o
+			    clk-pfd.o clk-busy.o clk.o \
+			    clk-fixup-div.o
 
 obj-$(CONFIG_IMX_HAVE_IOMUX_V1) += iomux-v1.o
 obj-$(CONFIG_ARCH_MXC_IOMUX_V3) += iomux-v3.o

arch/arm/mach-imx/clk-fixup-div.c new file +129 -0

129 lines not on this page · raw message

arch/arm/mach-imx/clk.h +4 -0

index 0e4e8bb..51eb3853 100644
@@ -49,6 +49,10 @@ struct clk *imx_clk_busy_mux(const char *name, void __iomem *reg, u8 shift,
 			     u8 width, void __iomem *busy_reg, u8 busy_shift,
 			     const char **parent_names, int num_parents);
 
+struct clk *imx_clk_fixup_divider(const char *name, const char *parent,
+				  void __iomem *reg, u8 shift, u8 width,
+				  void (*fixup)(u32 *val));
+
 static inline struct clk *imx_clk_fixed(const char *name, int rate)
 {
 	return clk_register_fixed_rate(NULL, name, NULL, CLK_IS_ROOT, rate);

Signature · 1 line

1.7.9.5

Shawn Guo

author

2013-07-10 15:22 UTC #2 lore raw

PATCH 2/3 ARM: imx: add common clock support for fixup mux

In reply to Shawn Guo

From: Liu Ying <[email protected]>

One register may have several fields to control some clocks. It is possible that the read/write values of some fields may map to different real functional values, so writing to the other fields in the same register may break a working clock tree. A real case is the aclk_podf field in the register 'CCM Serial Clock Multiplexer Register 1' of i.MX6Q/SDL SoC. This patch introduces a fixup hook for multiplexer clock which is called before writing a value to clock registers to support this kind of multiplexer clocks.

Signed-off-by Liu Ying <[email protected]>

Signed-off-by Shawn Guo <[email protected]>

---
 arch/arm/mach-imx/Makefile        |    2 +-
 arch/arm/mach-imx/clk-fixup-mux.c |  107 +++++++++++++++++++++++++++++++++++++
 arch/arm/mach-imx/clk.h           |    4 ++
 3 files changed, 112 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/mach-imx/clk-fixup-mux.c

arch/arm/mach-imx/Makefile +1 -1

index 92b91a2..5383c58 100644
@@ -16,7 +16,7 @@ obj-$(CONFIG_SOC_IMX5) += cpu-imx5.o mm-imx5.o clk-imx51-imx53.o ehci-imx5.o $(i
 
 obj-$(CONFIG_COMMON_CLK) += clk-pllv1.o clk-pllv2.o clk-pllv3.o clk-gate2.o \
 			    clk-pfd.o clk-busy.o clk.o \
-			    clk-fixup-div.o
+			    clk-fixup-div.o clk-fixup-mux.o
 
 obj-$(CONFIG_IMX_HAVE_IOMUX_V1) += iomux-v1.o
 obj-$(CONFIG_ARCH_MXC_IOMUX_V3) += iomux-v3.o

arch/arm/mach-imx/clk-fixup-mux.c new file +107 -0

107 lines not on this page · raw message

arch/arm/mach-imx/clk.h +4 -0

index 51eb3853..2534359 100644
@@ -53,6 +53,10 @@ struct clk *imx_clk_fixup_divider(const char *name, const char *parent,
 				  void __iomem *reg, u8 shift, u8 width,
 				  void (*fixup)(u32 *val));
 
+struct clk *imx_clk_fixup_mux(const char *name, void __iomem *reg,
+			      u8 shift, u8 width, const char **parents,
+			      int num_parents, void (*fixup)(u32 *val));
+
 static inline struct clk *imx_clk_fixed(const char *name, int rate)
 {
 	return clk_register_fixed_rate(NULL, name, NULL, CLK_IS_ROOT, rate);

Signature · 1 line

1.7.9.5

Shawn Guo

author

2013-07-10 15:22 UTC #3 lore raw

PATCH 3/3 ARM: imx6: change some clocks to fixup clocks

In reply to Shawn Guo

From: Liu Ying <[email protected]>

All the clocks controlled by the register 'CCM Serial Clock Multiplexer Register 1' should be fixup clocks. This patch changes those clocks from basic multiplexer or divider clocks to fixup clocks.

Signed-off-by Liu Ying <[email protected]>

Signed-off-by Shawn Guo <[email protected]>

---
 arch/arm/mach-imx/clk-imx6q.c  |   24 ++++++++++++------------
 arch/arm/mach-imx/clk-imx6sl.c |   20 ++++++++++----------
 arch/arm/mach-imx/clk.c        |   26 ++++++++++++++++++++++++++
 arch/arm/mach-imx/clk.h        |    2 ++
 4 files changed, 50 insertions(+), 22 deletions(-)

arch/arm/mach-imx/clk-imx6q.c +12 ~~-12~~

index 82a85ce..db9f8f5 100644
@@ -384,16 +384,16 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
 	clk[ipu2_di1_sel]     = imx_clk_mux("ipu2_di1_sel",     base + 0x38, 9,  3, ipu2_di1_sels,     ARRAY_SIZE(ipu2_di1_sels));
 	clk[hsi_tx_sel]       = imx_clk_mux("hsi_tx_sel",       base + 0x30, 28, 1, hsi_tx_sels,       ARRAY_SIZE(hsi_tx_sels));
 	clk[pcie_axi_sel]     = imx_clk_mux("pcie_axi_sel",     base + 0x18, 10, 1, pcie_axi_sels,     ARRAY_SIZE(pcie_axi_sels));
-	clk[ssi1_sel]         = imx_clk_mux("ssi1_sel",         base + 0x1c, 10, 2, ssi_sels,          ARRAY_SIZE(ssi_sels));
-	clk[ssi2_sel]         = imx_clk_mux("ssi2_sel",         base + 0x1c, 12, 2, ssi_sels,          ARRAY_SIZE(ssi_sels));
-	clk[ssi3_sel]         = imx_clk_mux("ssi3_sel",         base + 0x1c, 14, 2, ssi_sels,          ARRAY_SIZE(ssi_sels));
-	clk[usdhc1_sel]       = imx_clk_mux("usdhc1_sel",       base + 0x1c, 16, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels));
-	clk[usdhc2_sel]       = imx_clk_mux("usdhc2_sel",       base + 0x1c, 17, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels));
-	clk[usdhc3_sel]       = imx_clk_mux("usdhc3_sel",       base + 0x1c, 18, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels));
-	clk[usdhc4_sel]       = imx_clk_mux("usdhc4_sel",       base + 0x1c, 19, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels));
+	clk[ssi1_sel]         = imx_clk_fixup_mux("ssi1_sel",   base + 0x1c, 10, 2, ssi_sels,          ARRAY_SIZE(ssi_sels),          imx_cscmr1_fixup);
+	clk[ssi2_sel]         = imx_clk_fixup_mux("ssi2_sel",   base + 0x1c, 12, 2, ssi_sels,          ARRAY_SIZE(ssi_sels),          imx_cscmr1_fixup);
+	clk[ssi3_sel]         = imx_clk_fixup_mux("ssi3_sel",   base + 0x1c, 14, 2, ssi_sels,          ARRAY_SIZE(ssi_sels),          imx_cscmr1_fixup);
+	clk[usdhc1_sel]       = imx_clk_fixup_mux("usdhc1_sel", base + 0x1c, 16, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels),        imx_cscmr1_fixup);
+	clk[usdhc2_sel]       = imx_clk_fixup_mux("usdhc2_sel", base + 0x1c, 17, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels),        imx_cscmr1_fixup);
+	clk[usdhc3_sel]       = imx_clk_fixup_mux("usdhc3_sel", base + 0x1c, 18, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels),        imx_cscmr1_fixup);
+	clk[usdhc4_sel]       = imx_clk_fixup_mux("usdhc4_sel", base + 0x1c, 19, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels),        imx_cscmr1_fixup);
 	clk[enfc_sel]         = imx_clk_mux("enfc_sel",         base + 0x2c, 16, 2, enfc_sels,         ARRAY_SIZE(enfc_sels));
-	clk[emi_sel]          = imx_clk_mux("emi_sel",          base + 0x1c, 27, 2, emi_sels,          ARRAY_SIZE(emi_sels));
-	clk[emi_slow_sel]     = imx_clk_mux("emi_slow_sel",     base + 0x1c, 29, 2, emi_slow_sels,     ARRAY_SIZE(emi_slow_sels));
+	clk[emi_sel]          = imx_clk_fixup_mux("emi_sel",      base + 0x1c, 27, 2, emi_sels,        ARRAY_SIZE(emi_sels),          imx_cscmr1_fixup);
+	clk[emi_slow_sel]     = imx_clk_fixup_mux("emi_slow_sel", base + 0x1c, 29, 2, emi_slow_sels,   ARRAY_SIZE(emi_slow_sels),     imx_cscmr1_fixup);
 	clk[vdo_axi_sel]      = imx_clk_mux("vdo_axi_sel",      base + 0x18, 11, 1, vdo_axi_sels,      ARRAY_SIZE(vdo_axi_sels));
 	clk[vpu_axi_sel]      = imx_clk_mux("vpu_axi_sel",      base + 0x18, 14, 2, vpu_axi_sels,      ARRAY_SIZE(vpu_axi_sels));
 	clk[cko1_sel]         = imx_clk_mux("cko1_sel",         base + 0x60, 0,  4, cko1_sels,         ARRAY_SIZE(cko1_sels));

@@ -406,7 +406,7 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
 	clk[periph_clk2]      = imx_clk_divider("periph_clk2",      "periph_clk2_sel",   base + 0x14, 27, 3);
 	clk[periph2_clk2]     = imx_clk_divider("periph2_clk2",     "periph2_clk2_sel",  base + 0x14, 0,  3);
 	clk[ipg]              = imx_clk_divider("ipg",              "ahb",               base + 0x14, 8,  2);
-	clk[ipg_per]          = imx_clk_divider("ipg_per",          "ipg",               base + 0x1c, 0,  6);
+	clk[ipg_per]          = imx_clk_fixup_divider("ipg_per",    "ipg",               base + 0x1c, 0,  6, imx_cscmr1_fixup);
 	clk[esai_pred]        = imx_clk_divider("esai_pred",        "esai_sel",          base + 0x28, 9,  3);
 	clk[esai_podf]        = imx_clk_divider("esai_podf",        "esai_pred",         base + 0x28, 25, 3);
 	clk[asrc_pred]        = imx_clk_divider("asrc_pred",        "asrc_sel",          base + 0x30, 12, 3);

@@ -442,8 +442,8 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
 	clk[usdhc4_podf]      = imx_clk_divider("usdhc4_podf",      "usdhc4_sel",        base + 0x24, 22, 3);
 	clk[enfc_pred]        = imx_clk_divider("enfc_pred",        "enfc_sel",          base + 0x2c, 18, 3);
 	clk[enfc_podf]        = imx_clk_divider("enfc_podf",        "enfc_pred",         base + 0x2c, 21, 6);
-	clk[emi_podf]         = imx_clk_divider("emi_podf",         "emi_sel",           base + 0x1c, 20, 3);
-	clk[emi_slow_podf]    = imx_clk_divider("emi_slow_podf",    "emi_slow_sel",      base + 0x1c, 23, 3);
+	clk[emi_podf]         = imx_clk_fixup_divider("emi_podf",   "emi_sel",           base + 0x1c, 20, 3, imx_cscmr1_fixup);
+	clk[emi_slow_podf]    = imx_clk_fixup_divider("emi_slow_podf", "emi_slow_sel",   base + 0x1c, 23, 3, imx_cscmr1_fixup);
 	clk[vpu_axi_podf]     = imx_clk_divider("vpu_axi_podf",     "vpu_axi_sel",       base + 0x24, 25, 3);
 	clk[cko1_podf]        = imx_clk_divider("cko1_podf",        "cko1_sel",          base + 0x60, 4,  3);

arch/arm/mach-imx/clk-imx6sl.c +10 ~~-10~~

index a307ac2..a5c3c5d 100644
@@ -138,14 +138,14 @@ static void __init imx6sl_clocks_init(struct device_node *ccm_node)
 	clks[IMX6SL_CLK_PERIPH_CLK2_SEL]  = imx_clk_mux("periph_clk2_sel",  base + 0x18, 12, 2, periph_clk2_sels,  ARRAY_SIZE(periph_clk2_sels));
 	clks[IMX6SL_CLK_CSI_SEL]          = imx_clk_mux("csi_sel",          base + 0x3c, 9,  2, csi_lcdif_sels,    ARRAY_SIZE(csi_lcdif_sels));
 	clks[IMX6SL_CLK_LCDIF_AXI_SEL]    = imx_clk_mux("lcdif_axi_sel",    base + 0x3c, 14, 2, csi_lcdif_sels,    ARRAY_SIZE(csi_lcdif_sels));
-	clks[IMX6SL_CLK_USDHC1_SEL]       = imx_clk_mux("usdhc1_sel",       base + 0x1c, 16, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels));
-	clks[IMX6SL_CLK_USDHC2_SEL]       = imx_clk_mux("usdhc2_sel",       base + 0x1c, 17, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels));
-	clks[IMX6SL_CLK_USDHC3_SEL]       = imx_clk_mux("usdhc3_sel",       base + 0x1c, 18, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels));
-	clks[IMX6SL_CLK_USDHC4_SEL]       = imx_clk_mux("usdhc4_sel",       base + 0x1c, 19, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels));
-	clks[IMX6SL_CLK_SSI1_SEL]         = imx_clk_mux("ssi1_sel",         base + 0x1c, 10, 2, ssi_sels,          ARRAY_SIZE(ssi_sels));
-	clks[IMX6SL_CLK_SSI2_SEL]         = imx_clk_mux("ssi2_sel",         base + 0x1c, 12, 2, ssi_sels,          ARRAY_SIZE(ssi_sels));
-	clks[IMX6SL_CLK_SSI3_SEL]         = imx_clk_mux("ssi3_sel",         base + 0x1c, 14, 2, ssi_sels,          ARRAY_SIZE(ssi_sels));
-	clks[IMX6SL_CLK_PERCLK_SEL]       = imx_clk_mux("perclk_sel",       base + 0x1c, 6,  1, perclk_sels,       ARRAY_SIZE(perclk_sels));
+	clks[IMX6SL_CLK_USDHC1_SEL]       = imx_clk_fixup_mux("usdhc1_sel", base + 0x1c, 16, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels),  imx_cscmr1_fixup);
+	clks[IMX6SL_CLK_USDHC2_SEL]       = imx_clk_fixup_mux("usdhc2_sel", base + 0x1c, 17, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels),  imx_cscmr1_fixup);
+	clks[IMX6SL_CLK_USDHC3_SEL]       = imx_clk_fixup_mux("usdhc3_sel", base + 0x1c, 18, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels),  imx_cscmr1_fixup);
+	clks[IMX6SL_CLK_USDHC4_SEL]       = imx_clk_fixup_mux("usdhc4_sel", base + 0x1c, 19, 1, usdhc_sels,        ARRAY_SIZE(usdhc_sels),  imx_cscmr1_fixup);
+	clks[IMX6SL_CLK_SSI1_SEL]         = imx_clk_fixup_mux("ssi1_sel",   base + 0x1c, 10, 2, ssi_sels,          ARRAY_SIZE(ssi_sels),    imx_cscmr1_fixup);
+	clks[IMX6SL_CLK_SSI2_SEL]         = imx_clk_fixup_mux("ssi2_sel",   base + 0x1c, 12, 2, ssi_sels,          ARRAY_SIZE(ssi_sels),    imx_cscmr1_fixup);
+	clks[IMX6SL_CLK_SSI3_SEL]         = imx_clk_fixup_mux("ssi3_sel",   base + 0x1c, 14, 2, ssi_sels,          ARRAY_SIZE(ssi_sels),    imx_cscmr1_fixup);
+	clks[IMX6SL_CLK_PERCLK_SEL]       = imx_clk_fixup_mux("perclk_sel", base + 0x1c, 6,  1, perclk_sels,       ARRAY_SIZE(perclk_sels), imx_cscmr1_fixup);
 	clks[IMX6SL_CLK_PXP_AXI_SEL]      = imx_clk_mux("pxp_axi_sel",      base + 0x34, 6,  3, epdc_pxp_sels,     ARRAY_SIZE(epdc_pxp_sels));
 	clks[IMX6SL_CLK_EPDC_AXI_SEL]     = imx_clk_mux("epdc_axi_sel",     base + 0x34, 15, 3, epdc_pxp_sels,     ARRAY_SIZE(epdc_pxp_sels));
 	clks[IMX6SL_CLK_GPU2D_OVG_SEL]    = imx_clk_mux("gpu2d_ovg_sel",    base + 0x18, 4,  2, gpu2d_ovg_sels,    ARRAY_SIZE(gpu2d_ovg_sels));

@@ -179,14 +179,14 @@ static void __init imx6sl_clocks_init(struct device_node *ccm_node)
 	clks[IMX6SL_CLK_SSI2_PODF]         = imx_clk_divider("ssi2_podf",         "ssi2_pred",         base + 0x2c, 0,  6);
 	clks[IMX6SL_CLK_SSI3_PRED]         = imx_clk_divider("ssi3_pred",         "ssi3_sel",          base + 0x28, 22, 3);
 	clks[IMX6SL_CLK_SSI3_PODF]         = imx_clk_divider("ssi3_podf",         "ssi3_pred",         base + 0x28, 16, 6);
-	clks[IMX6SL_CLK_PERCLK]            = imx_clk_divider("perclk",            "perclk_sel",        base + 0x1c, 0,  6);
+	clks[IMX6SL_CLK_PERCLK]            = imx_clk_fixup_divider("perclk",      "perclk_sel",        base + 0x1c, 0,  6, imx_cscmr1_fixup);
 	clks[IMX6SL_CLK_PXP_AXI_PODF]      = imx_clk_divider("pxp_axi_podf",      "pxp_axi_sel",       base + 0x34, 3,  3);
 	clks[IMX6SL_CLK_EPDC_AXI_PODF]     = imx_clk_divider("epdc_axi_podf",     "epdc_axi_sel",      base + 0x34, 12, 3);
 	clks[IMX6SL_CLK_GPU2D_OVG_PODF]    = imx_clk_divider("gpu2d_ovg_podf",    "gpu2d_ovg_sel",     base + 0x18, 26, 3);
 	clks[IMX6SL_CLK_GPU2D_PODF]        = imx_clk_divider("gpu2d_podf",        "gpu2d_sel",         base + 0x18, 29, 3);
 	clks[IMX6SL_CLK_LCDIF_PIX_PRED]    = imx_clk_divider("lcdif_pix_pred",    "lcdif_pix_sel",     base + 0x38, 3,  3);
 	clks[IMX6SL_CLK_EPDC_PIX_PRED]     = imx_clk_divider("epdc_pix_pred",     "epdc_pix_sel",      base + 0x38, 12, 3);
-	clks[IMX6SL_CLK_LCDIF_PIX_PODF]    = imx_clk_divider("lcdif_pix_podf",    "lcdif_pix_pred",    base + 0x1c, 20, 3);
+	clks[IMX6SL_CLK_LCDIF_PIX_PODF]    = imx_clk_fixup_divider("lcdif_pix_podf", "lcdif_pix_pred", base + 0x1c, 20, 3, imx_cscmr1_fixup);
 	clks[IMX6SL_CLK_EPDC_PIX_PODF]     = imx_clk_divider("epdc_pix_podf",     "epdc_pix_pred",     base + 0x18, 23, 3);
 	clks[IMX6SL_CLK_SPDIF0_PRED]       = imx_clk_divider("spdif0_pred",       "spdif0_sel",        base + 0x30, 25, 3);
 	clks[IMX6SL_CLK_SPDIF0_PODF]       = imx_clk_divider("spdif0_podf",       "spdif0_pred",       base + 0x30, 22, 3);

arch/arm/mach-imx/clk.c +26 -0

index 55bc80a..edc35df 100644
@@ -37,3 +37,29 @@ struct clk * __init imx_obtain_fixed_clock(
 		clk = imx_clk_fixed(name, rate);
 	return clk;
 }
+
+/*
+ * This fixups the register CCM_CSCMR1 write value.
+ * The write/read/divider values of the aclk_podf field
+ * of that register have the relationship described by
+ * the following table:
+ *
+ * write value       read value        divider
+ * 3b'000            3b'110            7
+ * 3b'001            3b'111            8
+ * 3b'010            3b'100            5
+ * 3b'011            3b'101            6
+ * 3b'100            3b'010            3
+ * 3b'101            3b'011            4
+ * 3b'110            3b'000            1
+ * 3b'111            3b'001            2(default)
+ *
+ * That's why we do the xor operation below.
+ */
+#define CSCMR1_FIXUP	0x00600000
+
+void imx_cscmr1_fixup(u32 *val)
+{
+	*val ^= CSCMR1_FIXUP;
+	return;
+}

arch/arm/mach-imx/clk.h +2 -0

index 2534359..3451f1f 100644
@@ -6,6 +6,8 @@
 
 extern spinlock_t imx_ccm_lock;
 
+extern void imx_cscmr1_fixup(u32 *val);
+
 struct clk *imx_clk_pllv1(const char *name, const char *parent,
 		void __iomem *base);

Signature · 1 line

1.7.9.5

Dirk Behme

2013-07-12 09:15 UTC #4 lore raw

cover ARM: imx6: fix up buggy CCM_CSCMR1 register

In reply to Shawn Guo

Quoted 37 lines · Shawn Guo

There is a defect in bits 22 and 21 of i.MX6 CCM_CSCMR1 register. These two bits are inverted between read and write. That said, bit field CCM_CSCMR1[22-20] (aclk/emi_podf on imx6q/dl and lcdif_pix_podf on imx6sl) will be something as below between read and write.
   read    write    divider
    000     110       1
    001     111       2
    010     100       3
    011     101       4
    100     010       5
    101     011       6
    110     000       7
    111     001       8
To work around this hardware defect, every single read/modify/write sequence on the register will require a fix-up (invert bits 22 and 21) before writing the value into register. As there are dividers and multiplexers defined in the register, we choose to inherit the basic clk-divider and clk-mux and override the functions which writes register with a fix-up hooked in.
Shawn
Liu Ying (3):
ARM: imx: add common clock support for fixup div
ARM: imx: add common clock support for fixup mux
ARM: imx6: change some clocks to fixup clocks
  arch/arm/mach-imx/Makefile        |    3 +-
  arch/arm/mach-imx/clk-fixup-div.c |  129 +++++++++++++++++++++++++++++++++++++
  arch/arm/mach-imx/clk-fixup-mux.c |  107 ++++++++++++++++++++++++++++++
  arch/arm/mach-imx/clk-imx6q.c     |   24 +++----
  arch/arm/mach-imx/clk-imx6sl.c    |   20 +++---
  arch/arm/mach-imx/clk.c           |   26 ++++++++
  arch/arm/mach-imx/clk.h           |   10 +++
  7 files changed, 296 insertions(+), 23 deletions(-)

Quoted 2 lines

create mode 100644 arch/arm/mach-imx/clk-fixup-div.c create mode 100644 arch/arm/mach-imx/clk-fixup-mux.c

For the whole series:

Acked-by Dirk Behme <[email protected]>

Thanks

Dirk