From: Marek Vasut marex@denx.de
[ Upstream commit 69233bba6543a37755158ca3382765387b8078df ]
This driver is mixing 8-bit and 16-bit bus accessors for reasons unknown, however the speculation is that this was some sort of attempt to support the 8-bit bus mode.
As per the KS8851-16MLL documentation, all two registers accessed via the 8-bit accessors are internally 16-bit registers, so reading them using 16-bit accessors is fine. The KS_CCR read can be converted to 16-bit read outright, as it is already a concatenation of two 8-bit reads of that register. The KS_RXQCR accesses are 8-bit only, however writing the top 8 bits of the register is OK as well, since the driver caches the entire 16-bit register value anyway.
Finally, the driver is not used by any hardware in the kernel right now. The only hardware available to me is one with 16-bit bus, so I have no way to test the 8-bit bus mode, however it is unlikely this ever really worked anyway. If the 8-bit bus mode is ever required, it can be easily added by adjusting the 16-bit accessors to do 2 consecutive accesses, which is how this should have been done from the beginning.
Signed-off-by: Marek Vasut marex@denx.de Cc: David S. Miller davem@davemloft.net Cc: Lukas Wunner lukas@wunner.de Cc: Petr Stetiar ynezz@true.cz Cc: YueHaibing yuehaibing@huawei.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/micrel/ks8851_mll.c | 45 +++--------------------- 1 file changed, 5 insertions(+), 40 deletions(-)
diff --git a/drivers/net/ethernet/micrel/ks8851_mll.c b/drivers/net/ethernet/micrel/ks8851_mll.c index adbe0a6fe0db9..77d059d7f8c55 100644 --- a/drivers/net/ethernet/micrel/ks8851_mll.c +++ b/drivers/net/ethernet/micrel/ks8851_mll.c @@ -474,24 +474,6 @@ static int msg_enable; * chip is busy transferring packet data (RX/TX FIFO accesses). */
-/** - * ks_rdreg8 - read 8 bit register from device - * @ks : The chip information - * @offset: The register address - * - * Read a 8bit register from the chip, returning the result - */ -static u8 ks_rdreg8(struct ks_net *ks, int offset) -{ - u16 data; - u8 shift_bit = offset & 0x03; - u8 shift_data = (offset & 1) << 3; - ks->cmd_reg_cache = (u16) offset | (u16)(BE0 << shift_bit); - iowrite16(ks->cmd_reg_cache, ks->hw_addr_cmd); - data = ioread16(ks->hw_addr); - return (u8)(data >> shift_data); -} - /** * ks_rdreg16 - read 16 bit register from device * @ks : The chip information @@ -507,22 +489,6 @@ static u16 ks_rdreg16(struct ks_net *ks, int offset) return ioread16(ks->hw_addr); }
-/** - * ks_wrreg8 - write 8bit register value to chip - * @ks: The chip information - * @offset: The register address - * @value: The value to write - * - */ -static void ks_wrreg8(struct ks_net *ks, int offset, u8 value) -{ - u8 shift_bit = (offset & 0x03); - u16 value_write = (u16)(value << ((offset & 1) << 3)); - ks->cmd_reg_cache = (u16)offset | (BE0 << shift_bit); - iowrite16(ks->cmd_reg_cache, ks->hw_addr_cmd); - iowrite16(value_write, ks->hw_addr); -} - /** * ks_wrreg16 - write 16bit register value to chip * @ks: The chip information @@ -642,8 +608,7 @@ static void ks_read_config(struct ks_net *ks) u16 reg_data = 0;
/* Regardless of bus width, 8 bit read should always work.*/ - reg_data = ks_rdreg8(ks, KS_CCR) & 0x00FF; - reg_data |= ks_rdreg8(ks, KS_CCR+1) << 8; + reg_data = ks_rdreg16(ks, KS_CCR);
/* addr/data bus are multiplexed */ ks->sharedbus = (reg_data & CCR_SHARED) == CCR_SHARED; @@ -747,7 +712,7 @@ static inline void ks_read_qmu(struct ks_net *ks, u16 *buf, u32 len)
/* 1. set sudo DMA mode */ ks_wrreg16(ks, KS_RXFDPR, RXFDPR_RXFPAI); - ks_wrreg8(ks, KS_RXQCR, (ks->rc_rxqcr | RXQCR_SDA) & 0xff); + ks_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_SDA);
/* 2. read prepend data */ /** @@ -764,7 +729,7 @@ static inline void ks_read_qmu(struct ks_net *ks, u16 *buf, u32 len) ks_inblk(ks, buf, ALIGN(len, 4));
/* 4. reset sudo DMA Mode */ - ks_wrreg8(ks, KS_RXQCR, ks->rc_rxqcr); + ks_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr); }
/** @@ -997,13 +962,13 @@ static void ks_write_qmu(struct ks_net *ks, u8 *pdata, u16 len) ks->txh.txw[1] = cpu_to_le16(len);
/* 1. set sudo-DMA mode */ - ks_wrreg8(ks, KS_RXQCR, (ks->rc_rxqcr | RXQCR_SDA) & 0xff); + ks_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_SDA); /* 2. write status/lenth info */ ks_outblk(ks, ks->txh.txw, 4); /* 3. write pkt data */ ks_outblk(ks, (u16 *)pdata, ALIGN(len, 4)); /* 4. reset sudo-DMA mode */ - ks_wrreg8(ks, KS_RXQCR, ks->rc_rxqcr); + ks_wrreg16(ks, KS_RXQCR, ks->rc_rxqcr); /* 5. Enqueue Tx(move the pkt from TX buffer into TXQ) */ ks_wrreg16(ks, KS_TXQCR, TXQCR_METFE); /* 6. wait until TXQCR_METFE is auto-cleared */