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Message-Id: <1301088437-31915-1-git-send-email-mathieu.poirier@linaro.org>
Date: Fri, 25 Mar 2011 15:27:17 -0600
From: mathieu.poirier@...aro.org
To: steve.glendinning@...c.com
Cc: netdev@...r.kernel.org, lee.jones@...aro.org, patches@...aro.org,
linus.walleij@...aro.org, mathieu.poirier@...aro.org
Subject: [PATCH] net: allow shifted address in smsc911x
From: Alessandro Rubini <rubini@...dd.com>
At least one device I'm using needs address shifting to access
registers in the LAN9221 device (smsc911x driver). This patch
adds a shift parameter in platform_data. The feature must be
enabled at configuration time, because shifting by a pdata
parameter makes access slower in those devices where no shift is
needed (I tested one, it was 20% slower).
If the platform data requests shifted access but the feature is
unavailable, the probe method complains to the console. Board
config files should set the configuration option when needed.
Signed-off-by: Alessandro Rubini <rubini@...dd.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@...aro.org>
---
drivers/net/Kconfig | 10 ++++++++++
drivers/net/smsc911x.c | 37 +++++++++++++++++++++++++++++--------
include/linux/smsc911x.h | 1 +
3 files changed, 40 insertions(+), 8 deletions(-)
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index 0382332..70f2a17 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -1075,6 +1075,16 @@ config SMSC911X_ARCH_HOOKS
hooks for more comprehensive interrupt control and also to override
the source of the MAC address.
+config SMSC911X_ENABLE_SHIFTED_ADDRESS
+ def_bool n
+ depends on SMSC911X
+ help
+ The option allows device registers to be accessed in a sparse
+ way. This is needed to allow boards where the address bus is
+ not wired in the usual way. You'll most like don't need this
+ option, unless your vendor-provided board configuration file
+ enables it.
+
config NET_VENDOR_RACAL
bool "Racal-Interlan (Micom) NI cards"
depends on ISA
diff --git a/drivers/net/smsc911x.c b/drivers/net/smsc911x.c
index d70bde9..67fb5d6 100644
--- a/drivers/net/smsc911x.c
+++ b/drivers/net/smsc911x.c
@@ -69,6 +69,13 @@ static int debug = 3;
module_param(debug, int, 0);
MODULE_PARM_DESC(debug, "Debug level (0=none,...,16=all)");
+/* Shift value is uncommon and makes things slower: if not selected, force 0 */
+#ifdef CONFIG_SMSC911X_ENABLE_SHIFTED_ADDRESS
+#define __smsc_shift(pdata, reg) ((reg) << ((pdata)->config.shift))
+#else
+#define __smsc_shift(pdata, reg) (reg)
+#endif
+
struct smsc911x_data {
void __iomem *ioaddr;
@@ -121,11 +128,13 @@ struct smsc911x_data {
static inline u32 __smsc911x_reg_read(struct smsc911x_data *pdata, u32 reg)
{
if (pdata->config.flags & SMSC911X_USE_32BIT)
- return readl(pdata->ioaddr + reg);
+ return readl(pdata->ioaddr + __smsc_shift(pdata, reg));
if (pdata->config.flags & SMSC911X_USE_16BIT)
- return ((readw(pdata->ioaddr + reg) & 0xFFFF) |
- ((readw(pdata->ioaddr + reg + 2) & 0xFFFF) << 16));
+ return ((readw(pdata->ioaddr +
+ __smsc_shift(pdata, reg)) & 0xFFFF) |
+ ((readw(pdata->ioaddr +
+ __smsc_shift(pdata, reg + 2)) & 0xFFFF) << 16));
BUG();
return 0;
@@ -147,13 +156,15 @@ static inline void __smsc911x_reg_write(struct smsc911x_data *pdata, u32 reg,
u32 val)
{
if (pdata->config.flags & SMSC911X_USE_32BIT) {
- writel(val, pdata->ioaddr + reg);
+ writel(val, pdata->ioaddr + __smsc_shift(pdata, reg));
return;
}
if (pdata->config.flags & SMSC911X_USE_16BIT) {
- writew(val & 0xFFFF, pdata->ioaddr + reg);
- writew((val >> 16) & 0xFFFF, pdata->ioaddr + reg + 2);
+ writew(val & 0xFFFF,
+ pdata->ioaddr + __smsc_shift(pdata, reg));
+ writew((val >> 16) & 0xFFFF,
+ pdata->ioaddr + __smsc_shift(pdata, reg + 2));
return;
}
@@ -187,7 +198,8 @@ smsc911x_tx_writefifo(struct smsc911x_data *pdata, unsigned int *buf,
}
if (pdata->config.flags & SMSC911X_USE_32BIT) {
- writesl(pdata->ioaddr + TX_DATA_FIFO, buf, wordcount);
+ writesl(pdata->ioaddr + __smsc_shift(pdata, TX_DATA_FIFO),
+ buf, wordcount);
goto out;
}
@@ -219,7 +231,8 @@ smsc911x_rx_readfifo(struct smsc911x_data *pdata, unsigned int *buf,
}
if (pdata->config.flags & SMSC911X_USE_32BIT) {
- readsl(pdata->ioaddr + RX_DATA_FIFO, buf, wordcount);
+ readsl(pdata->ioaddr + __smsc_shift(pdata, RX_DATA_FIFO),
+ buf, wordcount);
goto out;
}
@@ -2023,6 +2036,14 @@ static int __devinit smsc911x_drv_probe(struct platform_device *pdev)
goto out_free_netdev_2;
}
+ /* If platform data wants a shifted address bus, we must support it */
+ if (pdata->config.shift && __smsc_shift(pdata, 1) == 1) {
+ pr_err("smsc911x: CONFIG_SMSC911X_ENABLE_SHIFTED_ADDRESS"
+ " is required but not available\n");
+ retval = -EINVAL;
+ goto out_unmap_io_3;
+ }
+
retval = smsc911x_init(dev);
if (retval < 0)
goto out_unmap_io_3;
diff --git a/include/linux/smsc911x.h b/include/linux/smsc911x.h
index 7144e8a..ea9a8c5 100644
--- a/include/linux/smsc911x.h
+++ b/include/linux/smsc911x.h
@@ -29,6 +29,7 @@ struct smsc911x_platform_config {
unsigned int irq_polarity;
unsigned int irq_type;
unsigned int flags;
+ unsigned int shift; /* used if CONFIG_SMSC911X_ENABLE_SHIFTED_ADDRESS */
phy_interface_t phy_interface;
unsigned char mac[6];
};
--
1.7.1
--
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