powerpc/serdes: Add the workaround for erratum A-007186

SerDes PLL is calibrated at reset. When the junction temperature
delta from the time the PLL is calibrated exceeds +56C/-66C,
jitter may increase and can cause PLL to unlock.

This workaround overwrite the SerDes registers with new values,
to calibrate SerDes registers.
These values are known to work fine for all temperature ranges.

This workaround is valid for B4, T4 and T2 platforms, so
added in their config.

Signed-off-by: Shaveta Leekha <shaveta@freescale.com>
Signed-off-by: Poonam Aggrwal <Poonam.Aggrwal@freescale.com>
[York Sun: replaced typedef ccsr_sfp_regs_t with struct ccsr_sfp_regs]
Reviewed-by: York Sun <yorksun@freescale.com>

2 files changed, 151 insertions, 0 deletions

diff --git a/arch/powerpc/cpu/mpc85xx/cmd_errata.c b/arch/powerpc/cpu/mpc85xx/cmd_errata.c
index f69c834..3a04a89 100644
--- a/arch/powerpc/cpu/mpc85xx/cmd_errata.c
+++ b/arch/powerpc/cpu/mpc85xx/cmd_errata.c
@@ -269,6 +269,9 @@ static int do_errata(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 #ifdef CONFIG_SYS_FSL_ERRATUM_USB14
 	puts("Work-around for Erratum USB14 enabled\n");
 #endif
+#ifdef CONFIG_SYS_FSL_ERRATUM_A007186
+	puts("Work-around for Erratum A007186 enabled\n");
+#endif
 #ifdef CONFIG_SYS_FSL_ERRATUM_A006593
 	puts("Work-around for Erratum A006593 enabled\n");
 #endif
diff --git a/arch/powerpc/cpu/mpc85xx/fsl_corenet2_serdes.c b/arch/powerpc/cpu/mpc85xx/fsl_corenet2_serdes.c
index 70e09ea..d1fc76a 100644
--- a/arch/powerpc/cpu/mpc85xx/fsl_corenet2_serdes.c
+++ b/arch/powerpc/cpu/mpc85xx/fsl_corenet2_serdes.c
@@ -147,12 +147,43 @@ int serdes_get_first_lane(u32 sd, enum srds_prtcl device)
 	return -ENODEV;
 }
 
+#define BC3_SHIFT	9
+#define DC3_SHIFT	6
+#define FC3_SHIFT	0
+#define BC2_SHIFT	19
+#define DC2_SHIFT	16
+#define FC2_SHIFT	10
+#define BC1_SHIFT	29
+#define DC1_SHIFT	26
+#define FC1_SHIFT	20
+#define BC_MASK		0x1
+#define DC_MASK		0x7
+#define FC_MASK		0x3F
+
+#define FUSE_VAL_MASK		0x00000003
+#define FUSE_VAL_SHIFT		30
+#define CR0_DCBIAS_SHIFT	5
+#define CR1_FCAP_SHIFT		15
+#define CR1_BCAP_SHIFT		29
+#define FCAP_MASK		0x001F8000
+#define BCAP_MASK		0x20000000
+#define BCAP_OVD_MASK		0x10000000
+#define BYP_CAL_MASK		0x02000000
+
 u64 serdes_init(u32 sd, u32 sd_addr, u32 sd_prctl_mask, u32 sd_prctl_shift)
 {
 	ccsr_gur_t *gur = (void __iomem *)(CONFIG_SYS_MPC85xx_GUTS_ADDR);
 	u64 serdes_prtcl_map = 0;
 	u32 cfg;
 	int lane;
+#ifdef CONFIG_SYS_FSL_ERRATUM_A007186
+	struct ccsr_sfp_regs  __iomem *sfp_regs =
+			(struct ccsr_sfp_regs __iomem *)(CONFIG_SYS_SFP_ADDR);
+	u32 pll_num, pll_status, bc, dc, fc, pll_cr_upd, pll_cr0, pll_cr1;
+	u32 bc_status, fc_status, dc_status, pll_sr2;
+	serdes_corenet_t  __iomem *srds_regs = (void *)sd_addr;
+	u32 sfp_spfr0, sel;
+#endif
 
 	cfg = in_be32(&gur->rcwsr[4]) & sd_prctl_mask;
 	/* Is serdes enabled at all? */
@@ -161,6 +192,123 @@ u64 serdes_init(u32 sd, u32 sd_addr, u32 sd_prctl_mask, u32 sd_prctl_shift)
 		return 0;
 	}
 
+/* Erratum A-007186
+ * Freescale Scratch Pad Fuse Register n (SFP_FSPFR0)
+ * The workaround requires factory pre-set SerDes calibration values to be
+ * read from a fuse block(Freescale Scratch Pad Fuse Register SFP_FSPFR0)
+ * These values have been shown to work across the
+ * entire temperature range for all SerDes. These values are then written into
+ * the SerDes registers to calibrate the SerDes PLL.
+ *
+ * This workaround for the protocols and rates that only have the Ring VCO.
+ */
+#ifdef CONFIG_SYS_FSL_ERRATUM_A007186
+	sfp_spfr0 = in_be32(&sfp_regs->fsl_spfr0);
+	debug("A007186: sfp_spfr0= %x\n", sfp_spfr0);
+
+	sel = (sfp_spfr0 >> FUSE_VAL_SHIFT) & FUSE_VAL_MASK;
+
+	if (sel == 0x01 || sel == 0x02) {
+		for (pll_num = 0; pll_num < SRDS_MAX_BANK; pll_num++) {
+			pll_status = in_be32(&srds_regs->bank[pll_num].pllcr0);
+			debug("A007186: pll_num=%x pllcr0=%x\n",
+			      pll_num, pll_status);
+			/* STEP 1 */
+			/* Read factory pre-set SerDes calibration values
+			 * from fuse block(SFP scratch register-sfp_spfr0)
+			 */
+			switch (pll_status & SRDS_PLLCR0_FRATE_SEL_MASK) {
+			case SRDS_PLLCR0_FRATE_SEL_3_0:
+			case SRDS_PLLCR0_FRATE_SEL_3_072:
+				debug("A007186: 3.0/3.072 protocol rate\n");
+				bc = (sfp_spfr0 >> BC1_SHIFT) & BC_MASK;
+				dc = (sfp_spfr0 >> DC1_SHIFT) & DC_MASK;
+				fc = (sfp_spfr0 >> FC1_SHIFT) & FC_MASK;
+				break;
+			case SRDS_PLLCR0_FRATE_SEL_3_125:
+				debug("A007186: 3.125 protocol rate\n");
+				bc = (sfp_spfr0 >> BC2_SHIFT) & BC_MASK;
+				dc = (sfp_spfr0 >> DC2_SHIFT) & DC_MASK;
+				fc = (sfp_spfr0 >> FC2_SHIFT) & FC_MASK;
+				break;
+			case SRDS_PLLCR0_FRATE_SEL_3_75:
+				debug("A007186: 3.75 protocol rate\n");
+				bc = (sfp_spfr0 >> BC1_SHIFT) & BC_MASK;
+				dc = (sfp_spfr0 >> DC1_SHIFT) & DC_MASK;
+				fc = (sfp_spfr0 >> FC1_SHIFT) & FC_MASK;
+				break;
+			default:
+				continue;
+			}
+
+			/* STEP 2 */
+			/* Write SRDSxPLLnCR1[11:16] = FC
+			 * Write SRDSxPLLnCR1[2] = BC
+			 */
+			pll_cr1 = in_be32(&srds_regs->bank[pll_num].pllcr1);
+			pll_cr_upd = (((bc << CR1_BCAP_SHIFT) & BCAP_MASK) |
+				      ((fc << CR1_FCAP_SHIFT) & FCAP_MASK));
+			out_be32(&srds_regs->bank[pll_num].pllcr1,
+				 (pll_cr_upd | pll_cr1));
+			debug("A007186: pll_num=%x Updated PLLCR1=%x\n",
+			      pll_num, (pll_cr_upd | pll_cr1));
+			/* Write SRDSxPLLnCR0[24:26] = DC
+			 */
+			pll_cr0 = in_be32(&srds_regs->bank[pll_num].pllcr0);
+			out_be32(&srds_regs->bank[pll_num].pllcr0,
+				 pll_cr0 | (dc << CR0_DCBIAS_SHIFT));
+			debug("A007186: pll_num=%x, Updated PLLCR0=%x\n",
+			      pll_num, (pll_cr0 | (dc << CR0_DCBIAS_SHIFT)));
+			/* Write SRDSxPLLnCR1[3] = 1
+			 * Write SRDSxPLLnCR1[6] = 1
+			 */
+			pll_cr1 = in_be32(&srds_regs->bank[pll_num].pllcr1);
+			pll_cr_upd = (BCAP_OVD_MASK | BYP_CAL_MASK);
+			out_be32(&srds_regs->bank[pll_num].pllcr1,
+				 (pll_cr_upd | pll_cr1));
+			debug("A007186: pll_num=%x Updated PLLCR1=%x\n",
+			      pll_num, (pll_cr_upd | pll_cr1));
+
+			/* STEP 3 */
+			/* Read the status Registers */
+			/* Verify SRDSxPLLnSR2[8] = BC */
+			pll_sr2 = in_be32(&srds_regs->bank[pll_num].pllsr2);
+			debug("A007186: pll_num=%x pllsr2=%x\n",
+			      pll_num, pll_sr2);
+			bc_status = (pll_sr2 >> 23) & BC_MASK;
+			if (bc_status != bc)
+				debug("BC mismatch\n");
+			fc_status = (pll_sr2 >> 16) & FC_MASK;
+			if (fc_status != fc)
+				debug("FC mismatch\n");
+			pll_cr0 = in_be32(&srds_regs->bank[pll_num].pllcr0);
+			out_be32(&srds_regs->bank[pll_num].pllcr0, pll_cr0 |
+								0x02000000);
+			pll_sr2 = in_be32(&srds_regs->bank[pll_num].pllsr2);
+			dc_status = (pll_sr2 >> 17) & DC_MASK;
+			if (dc_status != dc)
+				debug("DC mismatch\n");
+			pll_cr0 = in_be32(&srds_regs->bank[pll_num].pllcr0);
+			out_be32(&srds_regs->bank[pll_num].pllcr0, pll_cr0 &
+								0xfdffffff);
+
+			/* STEP 4 */
+			/* Wait 750us to verify the PLL is locked
+			 * by checking SRDSxPLLnCR0[8] = 1.
+			 */
+			udelay(750);
+			pll_status = in_be32(&srds_regs->bank[pll_num].pllcr0);
+			debug("A007186: pll_num=%x pllcr0=%x\n",
+			      pll_num, pll_status);
+
+			if ((pll_status & SRDS_PLLCR0_PLL_LCK) == 0)
+				printf("A007186 Serdes PLL not locked\n");
+			else
+				debug("A007186 Serdes PLL locked\n");
+		}
+	}
+#endif
+
 	cfg >>= sd_prctl_shift;
 	printf("Using SERDES%d Protocol: %d (0x%x)\n", sd + 1, cfg, cfg);
 	if (!is_serdes_prtcl_valid(sd, cfg))