[PATCH 3.13 14/22] net: mvneta: fix usage as a module on RGMII configurations

From: Greg Kroah-Hartman
Date: Tue Apr 01 2014 - 00:14:52 EST


3.13-stable review patch. If anyone has any objections, please let me know.

------------------

From: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>

commit e3a8786c10e75903f1269474e21fe8cb49c3a670 upstream.

Commit 5445eaf309ff ('mvneta: Try to fix mvneta when compiled as
module') fixed the mvneta driver to make it work properly when loaded
as a module in SGMII configuration, which was tested successful by the
author on the Armada XP OpenBlocks AX3, which uses SGMII.

However, it turns out that the Armada XP GP, which uses RGMII, is
affected by a similar problem: its SERDES configuration is lost when
mvneta is loaded as a module, because this configuration is set by the
bootloader, and then lost because the clock is gated by the clock
framework until the mvneta driver is loaded again and the clock is
re-enabled.

However, it turns out that for the RGMII case, setting the SERDES
configuration is not sufficient: the PCS enable bit in the
MVNETA_GMAC_CTRL_2 register must also be set, like in the SGMII
configuration.

Therefore, this commit reworks the SGMII/RGMII initialization: the
only difference between the two now is a different SERDES
configuration, all the rest is identical.

In detail, to achieve this, the commit:

* Renames MVNETA_SGMII_SERDES_CFG to MVNETA_SERDES_CFG because it is
not specific to SGMII, but also used on RGMII configurations.

* Adds a MVNETA_RGMII_SERDES_PROTO definition, that must be used as
the MVNETA_SERDES_CFG value in RGMII configurations.

* Removes the mvneta_gmac_rgmii_set() and mvneta_port_sgmii_config()
functions, and instead directly do the SGMII/RGMII configuration in
mvneta_port_up(), from where those functions where called. It is
worth mentioning that mvneta_gmac_rgmii_set() had an 'enable'
parameter that was always passed as '1', so it was pretty useless.

* Reworks the mvneta_port_up() function to set the MVNETA_SERDES_CFG
register to the appropriate value depending on the RGMII vs. SGMII
configuration. It also unconditionally set the PCS_ENABLE bit (was
already done for SGMII, but is now also needed for RGMII), and sets
the PORT_RGMII bit (which was already done for both SGMII and
RGMII).

This commit was successfully tested with mvneta compiled as a module,
on both the OpenBlocks AX3 (SGMII configuration) and the Armada XP GP
(RGMII configuration).

Reported-by: Steve McIntyre <steve@xxxxxxxxxx>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/ethernet/marvell/mvneta.c | 41 ++++++----------------------------
1 file changed, 8 insertions(+), 33 deletions(-)

--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -88,8 +88,9 @@
#define MVNETA_TX_IN_PRGRS BIT(1)
#define MVNETA_TX_FIFO_EMPTY BIT(8)
#define MVNETA_RX_MIN_FRAME_SIZE 0x247c
-#define MVNETA_SGMII_SERDES_CFG 0x24A0
+#define MVNETA_SERDES_CFG 0x24A0
#define MVNETA_SGMII_SERDES_PROTO 0x0cc7
+#define MVNETA_RGMII_SERDES_PROTO 0x0667
#define MVNETA_TYPE_PRIO 0x24bc
#define MVNETA_FORCE_UNI BIT(21)
#define MVNETA_TXQ_CMD_1 0x24e4
@@ -706,35 +707,6 @@ static void mvneta_rxq_bm_disable(struct
mvreg_write(pp, MVNETA_RXQ_CONFIG_REG(rxq->id), val);
}

-
-
-/* Sets the RGMII Enable bit (RGMIIEn) in port MAC control register */
-static void mvneta_gmac_rgmii_set(struct mvneta_port *pp, int enable)
-{
- u32 val;
-
- val = mvreg_read(pp, MVNETA_GMAC_CTRL_2);
-
- if (enable)
- val |= MVNETA_GMAC2_PORT_RGMII;
- else
- val &= ~MVNETA_GMAC2_PORT_RGMII;
-
- mvreg_write(pp, MVNETA_GMAC_CTRL_2, val);
-}
-
-/* Config SGMII port */
-static void mvneta_port_sgmii_config(struct mvneta_port *pp)
-{
- u32 val;
-
- val = mvreg_read(pp, MVNETA_GMAC_CTRL_2);
- val |= MVNETA_GMAC2_PCS_ENABLE;
- mvreg_write(pp, MVNETA_GMAC_CTRL_2, val);
-
- mvreg_write(pp, MVNETA_SGMII_SERDES_CFG, MVNETA_SGMII_SERDES_PROTO);
-}
-
/* Start the Ethernet port RX and TX activity */
static void mvneta_port_up(struct mvneta_port *pp)
{
@@ -2729,12 +2701,15 @@ static void mvneta_port_power_up(struct
mvreg_write(pp, MVNETA_UNIT_INTR_CAUSE, 0);

if (phy_mode == PHY_INTERFACE_MODE_SGMII)
- mvneta_port_sgmii_config(pp);
+ mvreg_write(pp, MVNETA_SERDES_CFG, MVNETA_SGMII_SERDES_PROTO);
+ else
+ mvreg_write(pp, MVNETA_SERDES_CFG, MVNETA_RGMII_SERDES_PROTO);

- mvneta_gmac_rgmii_set(pp, 1);
+ val = mvreg_read(pp, MVNETA_GMAC_CTRL_2);
+
+ val |= MVNETA_GMAC2_PCS_ENABLE | MVNETA_GMAC2_PORT_RGMII;

/* Cancel Port Reset */
- val = mvreg_read(pp, MVNETA_GMAC_CTRL_2);
val &= ~MVNETA_GMAC2_PORT_RESET;
mvreg_write(pp, MVNETA_GMAC_CTRL_2, val);



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