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authorDavid S. Miller <davem@davemloft.net>2020-03-29 21:25:29 -0700
committerDavid S. Miller <davem@davemloft.net>2020-03-29 21:25:29 -0700
commitf0b5989745c3e0e92424d36869a97e4e8df7ab13 (patch)
tree0e9759b9d6060bb94cad676b1b16e423d5ad2523 /drivers/net/ethernet/micrel
parent1a147b74c2fd4058dea0133cb2471724c3b3de09 (diff)
parent7111951b8d4973bda27ff663f2cf18b663d15b48 (diff)
downloadlinux-f0b5989745c3e0e92424d36869a97e4e8df7ab13.tar.bz2
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Minor comment conflict in mac80211. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/micrel')
-rw-r--r--drivers/net/ethernet/micrel/ks8851_mll.c56
1 files changed, 52 insertions, 4 deletions
diff --git a/drivers/net/ethernet/micrel/ks8851_mll.c b/drivers/net/ethernet/micrel/ks8851_mll.c
index 58579baf3f7a..45cc840d8e2e 100644
--- a/drivers/net/ethernet/micrel/ks8851_mll.c
+++ b/drivers/net/ethernet/micrel/ks8851_mll.c
@@ -157,6 +157,50 @@ static int msg_enable;
*/
/**
+ * ks_check_endian - Check whether endianness of the bus is correct
+ * @ks : The chip information
+ *
+ * The KS8851-16MLL EESK pin allows selecting the endianness of the 16bit
+ * bus. To maintain optimum performance, the bus endianness should be set
+ * such that it matches the endianness of the CPU.
+ */
+
+static int ks_check_endian(struct ks_net *ks)
+{
+ u16 cider;
+
+ /*
+ * Read CIDER register first, however read it the "wrong" way around.
+ * If the endian strap on the KS8851-16MLL in incorrect and the chip
+ * is operating in different endianness than the CPU, then the meaning
+ * of BE[3:0] byte-enable bits is also swapped such that:
+ * BE[3,2,1,0] becomes BE[1,0,3,2]
+ *
+ * Luckily for us, the byte-enable bits are the top four MSbits of
+ * the address register and the CIDER register is at offset 0xc0.
+ * Hence, by reading address 0xc0c0, which is not impacted by endian
+ * swapping, we assert either BE[3:2] or BE[1:0] while reading the
+ * CIDER register.
+ *
+ * If the bus configuration is correct, reading 0xc0c0 asserts
+ * BE[3:2] and this read returns 0x0000, because to read register
+ * with bottom two LSbits of address set to 0, BE[1:0] must be
+ * asserted.
+ *
+ * If the bus configuration is NOT correct, reading 0xc0c0 asserts
+ * BE[1:0] and this read returns non-zero 0x8872 value.
+ */
+ iowrite16(BE3 | BE2 | KS_CIDER, ks->hw_addr_cmd);
+ cider = ioread16(ks->hw_addr);
+ if (!cider)
+ return 0;
+
+ netdev_err(ks->netdev, "incorrect EESK endian strap setting\n");
+
+ return -EINVAL;
+}
+
+/**
* ks_rdreg16 - read 16 bit register from device
* @ks : The chip information
* @offset: The register address
@@ -166,7 +210,7 @@ static int msg_enable;
static u16 ks_rdreg16(struct ks_net *ks, int offset)
{
- ks->cmd_reg_cache = (u16)offset | ((BE3 | BE2) >> (offset & 0x02));
+ ks->cmd_reg_cache = (u16)offset | ((BE1 | BE0) << (offset & 0x02));
iowrite16(ks->cmd_reg_cache, ks->hw_addr_cmd);
return ioread16(ks->hw_addr);
}
@@ -181,7 +225,7 @@ static u16 ks_rdreg16(struct ks_net *ks, int offset)
static void ks_wrreg16(struct ks_net *ks, int offset, u16 value)
{
- ks->cmd_reg_cache = (u16)offset | ((BE3 | BE2) >> (offset & 0x02));
+ ks->cmd_reg_cache = (u16)offset | ((BE1 | BE0) << (offset & 0x02));
iowrite16(ks->cmd_reg_cache, ks->hw_addr_cmd);
iowrite16(value, ks->hw_addr);
}
@@ -197,7 +241,7 @@ static inline void ks_inblk(struct ks_net *ks, u16 *wptr, u32 len)
{
len >>= 1;
while (len--)
- *wptr++ = be16_to_cpu(ioread16(ks->hw_addr));
+ *wptr++ = (u16)ioread16(ks->hw_addr);
}
/**
@@ -211,7 +255,7 @@ static inline void ks_outblk(struct ks_net *ks, u16 *wptr, u32 len)
{
len >>= 1;
while (len--)
- iowrite16(cpu_to_be16(*wptr++), ks->hw_addr);
+ iowrite16(*wptr++, ks->hw_addr);
}
static void ks_disable_int(struct ks_net *ks)
@@ -1218,6 +1262,10 @@ static int ks8851_probe(struct platform_device *pdev)
goto err_free;
}
+ err = ks_check_endian(ks);
+ if (err)
+ goto err_free;
+
netdev->irq = platform_get_irq(pdev, 0);
if ((int)netdev->irq < 0) {