fsl/fman: implement several errata workarounds

Implemented workarounds for the following dTSEC Erratum:
A002, A004, A0012, A0014, A004839 on several operations
that involve MAC CFG register changes: adjust link,
rx pause frames, modify MAC address.

Signed-off-by: Florinel Iordache <florinel.iordache@nxp.com>
Acked-by: Madalin Bucur <madalin.bucur@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/fman/fman_dtsec.c

@@ -123,7 +123,7 @@
 #define DTSEC_ECNTRL_R100M		0x00000008
 #define DTSEC_ECNTRL_QSGMIIM		0x00000001
 
-#define DTSEC_TCTRL_GTS			0x00000020
+#define TCTRL_GTS			0x00000020
 
 #define RCTRL_PAL_MASK			0x001f0000
 #define RCTRL_PAL_SHIFT			16
@@ -863,6 +863,52 @@ int dtsec_cfg_pad_and_crc(struct fman_mac *dtsec, bool new_val)
 	return 0;
 }
 
+static void graceful_start(struct fman_mac *dtsec, enum comm_mode mode)
+{
+	struct dtsec_regs __iomem *regs = dtsec->regs;
+
+	if (mode & COMM_MODE_TX)
+		iowrite32be(ioread32be(&regs->tctrl) &
+				~TCTRL_GTS, &regs->tctrl);
+	if (mode & COMM_MODE_RX)
+		iowrite32be(ioread32be(&regs->rctrl) &
+				~RCTRL_GRS, &regs->rctrl);
+}
+
+static void graceful_stop(struct fman_mac *dtsec, enum comm_mode mode)
+{
+	struct dtsec_regs __iomem *regs = dtsec->regs;
+	u32 tmp;
+
+	/* Graceful stop - Assert the graceful Rx stop bit */
+	if (mode & COMM_MODE_RX) {
+		tmp = ioread32be(&regs->rctrl) | RCTRL_GRS;
+		iowrite32be(tmp, &regs->rctrl);
+
+		if (dtsec->fm_rev_info.major == 2) {
+			/* Workaround for dTSEC Errata A002 */
+			usleep_range(100, 200);
+		} else {
+			/* Workaround for dTSEC Errata A004839 */
+			usleep_range(10, 50);
+		}
+	}
+
+	/* Graceful stop - Assert the graceful Tx stop bit */
+	if (mode & COMM_MODE_TX) {
+		if (dtsec->fm_rev_info.major == 2) {
+			/* dTSEC Errata A004: Do not use TCTRL[GTS]=1 */
+			pr_debug("GTS not supported due to DTSEC_A004 Errata.\n");
+		} else {
+			tmp = ioread32be(&regs->tctrl) | TCTRL_GTS;
+			iowrite32be(tmp, &regs->tctrl);
+
+			/* Workaround for dTSEC Errata A0012, A0014 */
+			usleep_range(10, 50);
+		}
+	}
+}
+
 int dtsec_enable(struct fman_mac *dtsec, enum comm_mode mode)
 {
 	struct dtsec_regs __iomem *regs = dtsec->regs;
@@ -880,13 +926,8 @@ int dtsec_enable(struct fman_mac *dtsec, enum comm_mode mode)
 
 	iowrite32be(tmp, &regs->maccfg1);
 
-	/* Graceful start - clear the graceful receive stop bit */
-	if (mode & COMM_MODE_TX)
-		iowrite32be(ioread32be(&regs->tctrl) & ~DTSEC_TCTRL_GTS,
-			    &regs->tctrl);
-	if (mode & COMM_MODE_RX)
-		iowrite32be(ioread32be(&regs->rctrl) & ~RCTRL_GRS,
-			    &regs->rctrl);
+	/* Graceful start - clear the graceful Rx/Tx stop bit */
+	graceful_start(dtsec, mode);
 
 	return 0;
 }
@@ -899,23 +940,8 @@ int dtsec_disable(struct fman_mac *dtsec, enum comm_mode mode)
 	if (!is_init_done(dtsec->dtsec_drv_param))
 		return -EINVAL;
 
-	/* Gracefull stop - Assert the graceful transmit stop bit */
-	if (mode & COMM_MODE_RX) {
-		tmp = ioread32be(&regs->rctrl) | RCTRL_GRS;
-		iowrite32be(tmp, &regs->rctrl);
-
-		if (dtsec->fm_rev_info.major == 2)
-			usleep_range(100, 200);
-		else
-			udelay(10);
-	}
-
-	if (mode & COMM_MODE_TX) {
-		if (dtsec->fm_rev_info.major == 2)
-			pr_debug("GTS not supported due to DTSEC_A004 errata.\n");
-		else
-			pr_debug("GTS not supported due to DTSEC_A0014 errata.\n");
-	}
+	/* Graceful stop - Assert the graceful Rx/Tx stop bit */
+	graceful_stop(dtsec, mode);
 
 	tmp = ioread32be(&regs->maccfg1);
 	if (mode & COMM_MODE_RX)
@@ -933,11 +959,19 @@ int dtsec_set_tx_pause_frames(struct fman_mac *dtsec,
 			      u16 pause_time, u16 __maybe_unused thresh_time)
 {
 	struct dtsec_regs __iomem *regs = dtsec->regs;
+	enum comm_mode mode = COMM_MODE_NONE;
 	u32 ptv = 0;
 
 	if (!is_init_done(dtsec->dtsec_drv_param))
 		return -EINVAL;
 
+	if ((ioread32be(&regs->rctrl) & RCTRL_GRS) == 0)
+		mode |= COMM_MODE_RX;
+	if ((ioread32be(&regs->tctrl) & TCTRL_GTS) == 0)
+		mode |= COMM_MODE_TX;
+
+	graceful_stop(dtsec, mode);
+
 	if (pause_time) {
 		/* FM_BAD_TX_TS_IN_B_2_B_ERRATA_DTSEC_A003 Errata workaround */
 		if (dtsec->fm_rev_info.major == 2 && pause_time <= 320) {
@@ -958,17 +992,27 @@ int dtsec_set_tx_pause_frames(struct fman_mac *dtsec,
 		iowrite32be(ioread32be(&regs->maccfg1) & ~MACCFG1_TX_FLOW,
 			    &regs->maccfg1);
 
+	graceful_start(dtsec, mode);
+
 	return 0;
 }
 
 int dtsec_accept_rx_pause_frames(struct fman_mac *dtsec, bool en)
 {
 	struct dtsec_regs __iomem *regs = dtsec->regs;
+	enum comm_mode mode = COMM_MODE_NONE;
 	u32 tmp;
 
 	if (!is_init_done(dtsec->dtsec_drv_param))
 		return -EINVAL;
 
+	if ((ioread32be(&regs->rctrl) & RCTRL_GRS) == 0)
+		mode |= COMM_MODE_RX;
+	if ((ioread32be(&regs->tctrl) & TCTRL_GTS) == 0)
+		mode |= COMM_MODE_TX;
+
+	graceful_stop(dtsec, mode);
+
 	tmp = ioread32be(&regs->maccfg1);
 	if (en)
 		tmp |= MACCFG1_RX_FLOW;
@@ -976,20 +1020,34 @@ int dtsec_accept_rx_pause_frames(struct fman_mac *dtsec, bool en)
 		tmp &= ~MACCFG1_RX_FLOW;
 	iowrite32be(tmp, &regs->maccfg1);
 
+	graceful_start(dtsec, mode);
+
 	return 0;
 }
 
 int dtsec_modify_mac_address(struct fman_mac *dtsec, enet_addr_t *enet_addr)
 {
+	struct dtsec_regs __iomem *regs = dtsec->regs;
+	enum comm_mode mode = COMM_MODE_NONE;
+
 	if (!is_init_done(dtsec->dtsec_drv_param))
 		return -EINVAL;
 
+	if ((ioread32be(&regs->rctrl) & RCTRL_GRS) == 0)
+		mode |= COMM_MODE_RX;
+	if ((ioread32be(&regs->tctrl) & TCTRL_GTS) == 0)
+		mode |= COMM_MODE_TX;
+
+	graceful_stop(dtsec, mode);
+
 	/* Initialize MAC Station Address registers (1 & 2)
 	 * Station address have to be swapped (big endian to little endian
 	 */
 	dtsec->addr = ENET_ADDR_TO_UINT64(*enet_addr);
 	set_mac_address(dtsec->regs, (u8 *)(*enet_addr));
 
+	graceful_start(dtsec, mode);
+
 	return 0;
 }
 
@@ -1162,11 +1220,19 @@ int dtsec_set_promiscuous(struct fman_mac *dtsec, bool new_val)
 int dtsec_adjust_link(struct fman_mac *dtsec, u16 speed)
 {
 	struct dtsec_regs __iomem *regs = dtsec->regs;
+	enum comm_mode mode = COMM_MODE_NONE;
 	u32 tmp;
 
 	if (!is_init_done(dtsec->dtsec_drv_param))
 		return -EINVAL;
 
+	if ((ioread32be(&regs->rctrl) & RCTRL_GRS) == 0)
+		mode |= COMM_MODE_RX;
+	if ((ioread32be(&regs->tctrl) & TCTRL_GTS) == 0)
+		mode |= COMM_MODE_TX;
+
+	graceful_stop(dtsec, mode);
+
 	tmp = ioread32be(&regs->maccfg2);
 
 	/* Full Duplex */
@@ -1186,6 +1252,8 @@ int dtsec_adjust_link(struct fman_mac *dtsec, u16 speed)
 		tmp &= ~DTSEC_ECNTRL_R100M;
 	iowrite32be(tmp, &regs->ecntrl);
 
+	graceful_start(dtsec, mode);
+
 	return 0;
 }