[PATCH 6/6] net: smmac: allow configuring lower pbl values

[Niklas Cassel]

From: Niklas Cassel 

The driver currently always sets the PBLx8/PBLx4 bit, which means that
the pbl values configured via the pbl/txpbl/rxpbl DT properties are
always multiplied by 8/4 in the hardware.

In order to allow the DT to configure lower pbl values, while at the
same time not changing behavior of any existing device trees using the
pbl/txpbl/rxpbl settings, add a property to disable the multiplication
of the pbl by 8/4 in the hardware.

Suggested-by: Rabin Vincent 
Signed-off-by: Niklas Cassel 
---
 Documentation/devicetree/bindings/net/stmmac.txt  | 2 ++
 Documentation/networking/stmmac.txt   | 5 -
 drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c   | 3 ++-
 drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c  | 3 ++-
 drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c  | 2 ++
 drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 1 +
 include/linux/stmmac.h| 1 +
 7 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/stmmac.txt 
b/Documentation/devicetree/bindings/net/stmmac.txt
index 8080038ff1b2..128da752fec9 100644
--- a/Documentation/devicetree/bindings/net/stmmac.txt
+++ b/Documentation/devicetree/bindings/net/stmmac.txt
@@ -39,6 +39,8 @@ Optional properties:
If set, DMA tx will use this value rather than snps,pbl.
 - snps,rxpbl   Rx Programmable Burst Length. Only for GMAC and newer.
If set, DMA rx will use this value rather than snps,pbl.
+- snps,no-pbl-x8   Don't multiply the pbl/txpbl/rxpbl values by 8.
+   For core rev < 3.50, don't multiply the values by 4.
 - snps,aal Address-Aligned Beats
 - snps,fixed-burst Program the DMA to use the fixed burst mode
 - snps,mixed-burst Program the DMA to use the mixed burst mode
diff --git a/Documentation/networking/stmmac.txt 
b/Documentation/networking/stmmac.txt
index 82c8e496b4bb..d3376c5fbcf0 100644
--- a/Documentation/networking/stmmac.txt
+++ b/Documentation/networking/stmmac.txt
@@ -153,8 +153,9 @@ Where:
  o dma_cfg: internal DMA parameters
o pbl: the Programmable Burst Length is maximum number of beats to
be transferred in one DMA transaction.
-   GMAC also enables the 4xPBL by default.
+   GMAC also enables the 4xPBL by default. (8xPBL for GMAC 3.50 and newer)
o txpbl/rxpbl: GMAC and newer supports independent DMA pbl for tx/rx.
+   o pblx8: Enable 8xPBL (4xPBL for core rev < 3.50). Enabled by default.
o fixed_burst/mixed_burst/aal
  o clk_csr: fixed CSR Clock range selection.
  o has_gmac: uses the GMAC core.
@@ -209,6 +210,7 @@ struct stmmac_dma_cfg {
int pbl;
int txpbl;
int rxpbl;
+   bool pblx8;
int fixed_burst;
int mixed_burst;
bool aal;
@@ -220,6 +222,7 @@ Where:
 If set, DMA tx will use this value rather than pbl.
  o rxpbl: Receive Programmable Burst Length. Only for GMAC and newer.
 If set, DMA rx will use this value rather than pbl.
+ o pblx8: Enable 8xPBL (4xPBL for core rev < 3.50). Enabled by default.
  o fixed_burst: program the DMA to use the fixed burst mode
  o mixed_burst: program the DMA to use the mixed burst mode
  o aal: Address-Aligned Beats
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c 
b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
index 1dd34fb4c1a9..1d313af647b4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
@@ -96,7 +96,8 @@ static void dwmac1000_dma_init(void __iomem *ioaddr,
 * Note: before stmmac core 3.50 this mode bit was 4xPBL, and
 * post 3.5 mode bit acts as 8*PBL.
 */
-   value |= DMA_BUS_MODE_MAXPBL;
+   if (dma_cfg->pblx8)
+   value |= DMA_BUS_MODE_MAXPBL;
value |= DMA_BUS_MODE_USP;
value &= ~(DMA_BUS_MODE_PBL_MASK | DMA_BUS_MODE_RPBL_MASK);
value |= (txpbl << DMA_BUS_MODE_PBL_SHIFT);
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c 
b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
index 0bf47825bfeb..0f7110d19a4a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
@@ -82,7 +82,8 @@ static void dwmac4_dma_init_channel(void __iomem *ioaddr,
 * on each channel
 */
value = readl(ioaddr + DMA_CHAN_CONTROL(channel));
-   value = value | DMA_BUS_MODE_PBL;
+   if (dma_cfg->pblx8)
+   value = value | DMA_BUS_MODE_PBL;
writel(value, ioaddr + DMA_CHAN_CONTROL(channel));
 
value = readl(ioaddr + DMA_CHAN_TX_CONTROL(channel));
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c 
b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
index 56c8a2342c14..a2831773431a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
+++ 

[PATCH 6/6] net: smmac: allow configuring lower pbl values

[Niklas Cassel]

From: Niklas Cassel 

The driver currently always sets the PBLx8/PBLx4 bit, which means that
the pbl values configured via the pbl/txpbl/rxpbl DT properties are
always multiplied by 8/4 in the hardware.

In order to allow the DT to configure lower pbl values, while at the
same time not changing behavior of any existing device trees using the
pbl/txpbl/rxpbl settings, add a property to disable the multiplication
of the pbl by 8/4 in the hardware.

Suggested-by: Rabin Vincent 
Signed-off-by: Niklas Cassel 
---
 Documentation/devicetree/bindings/net/stmmac.txt  | 2 ++
 Documentation/networking/stmmac.txt   | 5 -
 drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c   | 3 ++-
 drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c  | 3 ++-
 drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c  | 2 ++
 drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 1 +
 include/linux/stmmac.h| 1 +
 7 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/stmmac.txt 
b/Documentation/devicetree/bindings/net/stmmac.txt
index 8080038ff1b2..128da752fec9 100644
--- a/Documentation/devicetree/bindings/net/stmmac.txt
+++ b/Documentation/devicetree/bindings/net/stmmac.txt
@@ -39,6 +39,8 @@ Optional properties:
If set, DMA tx will use this value rather than snps,pbl.
 - snps,rxpbl   Rx Programmable Burst Length. Only for GMAC and newer.
If set, DMA rx will use this value rather than snps,pbl.
+- snps,no-pbl-x8   Don't multiply the pbl/txpbl/rxpbl values by 8.
+   For core rev < 3.50, don't multiply the values by 4.
 - snps,aal Address-Aligned Beats
 - snps,fixed-burst Program the DMA to use the fixed burst mode
 - snps,mixed-burst Program the DMA to use the mixed burst mode
diff --git a/Documentation/networking/stmmac.txt 
b/Documentation/networking/stmmac.txt
index 82c8e496b4bb..d3376c5fbcf0 100644
--- a/Documentation/networking/stmmac.txt
+++ b/Documentation/networking/stmmac.txt
@@ -153,8 +153,9 @@ Where:
  o dma_cfg: internal DMA parameters
o pbl: the Programmable Burst Length is maximum number of beats to
be transferred in one DMA transaction.
-   GMAC also enables the 4xPBL by default.
+   GMAC also enables the 4xPBL by default. (8xPBL for GMAC 3.50 and newer)
o txpbl/rxpbl: GMAC and newer supports independent DMA pbl for tx/rx.
+   o pblx8: Enable 8xPBL (4xPBL for core rev < 3.50). Enabled by default.
o fixed_burst/mixed_burst/aal
  o clk_csr: fixed CSR Clock range selection.
  o has_gmac: uses the GMAC core.
@@ -209,6 +210,7 @@ struct stmmac_dma_cfg {
int pbl;
int txpbl;
int rxpbl;
+   bool pblx8;
int fixed_burst;
int mixed_burst;
bool aal;
@@ -220,6 +222,7 @@ Where:
 If set, DMA tx will use this value rather than pbl.
  o rxpbl: Receive Programmable Burst Length. Only for GMAC and newer.
 If set, DMA rx will use this value rather than pbl.
+ o pblx8: Enable 8xPBL (4xPBL for core rev < 3.50). Enabled by default.
  o fixed_burst: program the DMA to use the fixed burst mode
  o mixed_burst: program the DMA to use the mixed burst mode
  o aal: Address-Aligned Beats
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c 
b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
index 1dd34fb4c1a9..1d313af647b4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
@@ -96,7 +96,8 @@ static void dwmac1000_dma_init(void __iomem *ioaddr,
 * Note: before stmmac core 3.50 this mode bit was 4xPBL, and
 * post 3.5 mode bit acts as 8*PBL.
 */
-   value |= DMA_BUS_MODE_MAXPBL;
+   if (dma_cfg->pblx8)
+   value |= DMA_BUS_MODE_MAXPBL;
value |= DMA_BUS_MODE_USP;
value &= ~(DMA_BUS_MODE_PBL_MASK | DMA_BUS_MODE_RPBL_MASK);
value |= (txpbl << DMA_BUS_MODE_PBL_SHIFT);
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c 
b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
index 0bf47825bfeb..0f7110d19a4a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c
@@ -82,7 +82,8 @@ static void dwmac4_dma_init_channel(void __iomem *ioaddr,
 * on each channel
 */
value = readl(ioaddr + DMA_CHAN_CONTROL(channel));
-   value = value | DMA_BUS_MODE_PBL;
+   if (dma_cfg->pblx8)
+   value = value | DMA_BUS_MODE_PBL;
writel(value, ioaddr + DMA_CHAN_CONTROL(channel));
 
value = readl(ioaddr + DMA_CHAN_TX_CONTROL(channel));
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c 
b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
index 56c8a2342c14..a2831773431a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pci.c
@@ -81,6 +81,7 @@