On 10/21/2016 01:53 PM, Giuseppe CAVALLARO wrote:

Hello

some my minor cents below

On 10/21/2016 12:20 PM, Joachim Eastwood wrote:

quoted

Hi Neil,

On 21 October 2016 at 10:44, Neil Armstrong [off-list ref] wrote:

quoted

Add Synopsys Designware MAC Glue layer for the Oxford Semiconductor OX820.

Signed-off-by: Neil Armstrong <redacted>
---
 .../devicetree/bindings/net/oxnas-dwmac.txt        |  44 +++++
 drivers/net/ethernet/stmicro/stmmac/Kconfig        |  11 ++
 drivers/net/ethernet/stmicro/stmmac/Makefile       |   1 +
 drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c  | 219 +++++++++++++++++++++
 4 files changed, 275 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/oxnas-dwmac.txt
 create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c

Changes since RFC at https://patchwork.kernel.org/patch/9387257 :
 - Drop init/exit callbacks
 - Implement proper remove and PM callback
 - Call init from probe
 - Disable/Unprepare clock if stmmac probe fails

<snip>

quoted

+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-oxnas.c

@@ -0,0 +1,219 @@
+/*
+ * Oxford Semiconductor OXNAS DWMAC glue layer
+ *
+ * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
+ * Copyright (C) 2014 Daniel Golle <daniel@makrotopia.org>
+ * Copyright (C) 2013 Ma Haijun <mahaijuns@gmail.com>
+ * Copyright (C) 2012 John Crispin <blogic@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <linux/stmmac.h>
+
+#include "stmmac_platform.h"
+
+/* System Control regmap offsets */
+#define OXNAS_DWMAC_CTRL_REGOFFSET     0x78
+#define OXNAS_DWMAC_DELAY_REGOFFSET    0x100
+
+/* Control Register */
+#define DWMAC_CKEN_RX_IN        14
+#define DWMAC_CKEN_RXN_OUT      13
+#define DWMAC_CKEN_RX_OUT       12
+#define DWMAC_CKEN_TX_IN        10
+#define DWMAC_CKEN_TXN_OUT      9
+#define DWMAC_CKEN_TX_OUT       8
+#define DWMAC_RX_SOURCE         7
+#define DWMAC_TX_SOURCE         6
+#define DWMAC_LOW_TX_SOURCE     4
+#define DWMAC_AUTO_TX_SOURCE    3
+#define DWMAC_RGMII             2
+#define DWMAC_SIMPLE_MUX        1
+#define DWMAC_CKEN_GTX          0
+
+/* Delay register */
+#define DWMAC_TX_VARDELAY_SHIFT                0
+#define DWMAC_TXN_VARDELAY_SHIFT       8
+#define DWMAC_RX_VARDELAY_SHIFT                16
+#define DWMAC_RXN_VARDELAY_SHIFT       24
+#define DWMAC_TX_VARDELAY(d)           ((d) << DWMAC_TX_VARDELAY_SHIFT)
+#define DWMAC_TXN_VARDELAY(d)          ((d) << DWMAC_TXN_VARDELAY_SHIFT)
+#define DWMAC_RX_VARDELAY(d)           ((d) << DWMAC_RX_VARDELAY_SHIFT)
+#define DWMAC_RXN_VARDELAY(d)          ((d) << DWMAC_RXN_VARDELAY_SHIFT)
+
+struct oxnas_dwmac {
+       struct device   *dev;
+       struct clk      *clk;
+       struct regmap   *regmap;
+};
+
+static int oxnas_dwmac_init(struct oxnas_dwmac *dwmac)
+{
+       unsigned int value;
+       int ret;
+
+       /* Reset HW here before changing the glue configuration */
+       ret = device_reset(dwmac->dev);
+       if (ret)
+               return ret;
+
+       clk_prepare_enable(dwmac->clk);

You might want to check the return value from clk_prepare_enable() as well.

quoted

+
+       ret = regmap_read(dwmac->regmap, OXNAS_DWMAC_CTRL_REGOFFSET, &value);
+       if (ret < 0)
+               return ret;
+
+       /* Enable GMII_GTXCLK to follow GMII_REFCLK, required for gigabit PHY */
+       value |= BIT(DWMAC_CKEN_GTX);
+       /* Use simple mux for 25/125 Mhz clock switching */
+       value |= BIT(DWMAC_SIMPLE_MUX);
+       /* set auto switch tx clock source */
+       value |= BIT(DWMAC_AUTO_TX_SOURCE);
+       /* enable tx & rx vardelay */
+       value |= BIT(DWMAC_CKEN_TX_OUT);
+       value |= BIT(DWMAC_CKEN_TXN_OUT);
+       value |= BIT(DWMAC_CKEN_TX_IN);
+       value |= BIT(DWMAC_CKEN_RX_OUT);
+       value |= BIT(DWMAC_CKEN_RXN_OUT);
+       value |= BIT(DWMAC_CKEN_RX_IN);
+       regmap_write(dwmac->regmap, OXNAS_DWMAC_CTRL_REGOFFSET, value);
+
+       /* set tx & rx vardelay */
+       value = DWMAC_TX_VARDELAY(4);
+       value |= DWMAC_TXN_VARDELAY(2);
+       value |= DWMAC_RX_VARDELAY(10);
+       value |= DWMAC_RXN_VARDELAY(8);
+       regmap_write(dwmac->regmap, OXNAS_DWMAC_DELAY_REGOFFSET, value);

there is no if condition so, I can suggest you, to hardwire
value with macros instead of computing at runtime:

e.g.

var = DWMAC_VARDELAY where
 #define DWMAC_VARDELAY (DWMAC_TX_VARDELAY(4) | ...)

... same for OXNAS_DWMAC_CTRL_REGOFFSET where
BIT(DWMAC_CKEN_ ... ) should be re-organized as macros,
I mean:
#define DWMAC_CKEN_..     BIT(xxx)

I will think about something similar for v2,

Thanks,

Neil

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