[U-Boot] [PATCH 1/4] powerpc/85xx: Implement work-around for P4080 erratum SERDES-A005

[Kumar Gala <galak@kernel.crashing.org>]

From: Timur Tabi <timur@freescale.com>

SerDes PLL bandwidth default setting is incorrect when no lanes are
configured as PCI Express.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
---
 arch/powerpc/cpu/mpc85xx/cmd_errata.c         |    3 ++
 arch/powerpc/cpu/mpc85xx/fsl_corenet_serdes.c |   48 +++++++++++++++++++++++++
 arch/powerpc/include/asm/config_mpc85xx.h     |    1 +
 3 files changed, 52 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/cpu/mpc85xx/cmd_errata.c b/arch/powerpc/cpu/mpc85xx/cmd_errata.c
index 0564816..7b9f773 100644
--- a/arch/powerpc/cpu/mpc85xx/cmd_errata.c
+++ b/arch/powerpc/cpu/mpc85xx/cmd_errata.c
@@ -47,6 +47,9 @@ static int do_errata(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 #if defined(CONFIG_SYS_P4080_ERRATUM_SERDES9)
 	puts("Work-around for Erratum SERDES9 enabled\n");
 #endif
+#if defined(CONFIG_SYS_P4080_ERRATUM_SERDES_A005)
+	puts("Work-around for Erratum SERDES-A005 enabled\n");
+#endif
 #if defined(CONFIG_SYS_P4080_ERRATUM_CPU22)
 	puts("Work-around for Erratum CPU22 enabled\n");
 #endif
diff --git a/arch/powerpc/cpu/mpc85xx/fsl_corenet_serdes.c b/arch/powerpc/cpu/mpc85xx/fsl_corenet_serdes.c
index d39f963..edacdb8 100644
--- a/arch/powerpc/cpu/mpc85xx/fsl_corenet_serdes.c
+++ b/arch/powerpc/cpu/mpc85xx/fsl_corenet_serdes.c
@@ -386,6 +386,52 @@ static void p4080_erratum_serdes8(serdes_corenet_t *regs, ccsr_gur_t *gur,
 }
 #endif
 
+#ifdef CONFIG_SYS_P4080_ERRATUM_SERDES_A005
+/*
+ * If PCIe is not selected as a protocol for any lanes driven by a given PLL,
+ * that PLL should have SRDSBnPLLCR1[PLLBW_SEL] = 0.
+ */
+static void p4080_erratum_serdes_a005(serdes_corenet_t *regs, unsigned int cfg)
+{
+	enum srds_prtcl device;
+
+	switch (cfg) {
+	case 0x13:
+	case 0x16:
+		/*
+		 * If SRDS_PRTCL = 0x13 or 0x16, set SRDSB1PLLCR1[PLLBW_SEL]
+		 * to 0.
+		 */
+		clrbits_be32(&regs->bank[FSL_SRDS_BANK_1].pllcr1,
+			     SRDS_PLLCR1_PLL_BWSEL);
+		break;
+	case 0x19:
+		/*
+		 * If SRDS_PRTCL = 0x19, set SRDSB1PLLCR1[PLLBW_SEL] to 0 and
+		 * SRDSB3PLLCR1[PLLBW_SEL] to 1.
+		 */
+		clrbits_be32(&regs->bank[FSL_SRDS_BANK_1].pllcr1,
+			     SRDS_PLLCR1_PLL_BWSEL);
+		setbits_be32(&regs->bank[FSL_SRDS_BANK_3].pllcr1,
+			     SRDS_PLLCR1_PLL_BWSEL);
+		break;
+	}
+
+	/*
+	 * Set SRDSBnPLLCR1[PLLBW_SEL] to 0 for each bank that selects XAUI
+	 * before XAUI is initialized.
+	 */
+	for (device = XAUI_FM1; device <= XAUI_FM2; device++) {
+		if (is_serdes_configured(device)) {
+			int bank = serdes_get_bank_by_device(cfg, device);
+
+			clrbits_be32(&regs->bank[bank].pllcr1,
+				     SRDS_PLLCR1_PLL_BWSEL);
+		}
+	}
+}
+#endif
+
 void fsl_serdes_init(void)
 {
 	ccsr_gur_t *gur = (void *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
@@ -570,6 +616,8 @@ void fsl_serdes_init(void)
 	puts("\n");
 #endif
 
+#ifdef CONFIG_SYS_P4080_ERRATUM_SERDES_A005
+	p4080_erratum_serdes_a005(srds_regs, cfg);
 #endif
 
 	for (idx = 0; idx < SRDS_MAX_BANK; idx++) {
diff --git a/arch/powerpc/include/asm/config_mpc85xx.h b/arch/powerpc/include/asm/config_mpc85xx.h
index d71c3fc..207f717 100644
--- a/arch/powerpc/include/asm/config_mpc85xx.h
+++ b/arch/powerpc/include/asm/config_mpc85xx.h
@@ -315,6 +315,7 @@
 #define CONFIG_SYS_P4080_ERRATUM_CPU22
 #define CONFIG_SYS_P4080_ERRATUM_SERDES8
 #define CONFIG_SYS_P4080_ERRATUM_SERDES9
+#define CONFIG_SYS_P4080_ERRATUM_SERDES_A005
 
 /* P5010 is single core version of P5020 */
 #elif defined(CONFIG_PPC_P5010)
-- 
1.7.3.4