From 6665e62387c64054493411d00c7b0a5a37af88a5 Mon Sep 17 00:00:00 2001 From: Helmut Buchsbaum Date: Tue, 9 Feb 2016 20:47:16 +0100 Subject: [PATCH] net: phy: spi_ks8995: generalize creation of SPI commands Prepare creating SPI reads and writes for other switch families. The KS8995 family uses the straight forward <8bit CMD><8bit ADDR> sequence. To be able to support KSZ8795 family, which uses <3bit CMD><12bit ADDR><1 bit TR> make the SPI command creation chip variant dependent. Signed-off-by: Helmut Buchsbaum Signed-off-by: David S. Miller --- drivers/net/phy/spi_ks8995.c | 46 +++++++++++++++++++++++++++--------- 1 file changed, 35 insertions(+), 11 deletions(-) diff --git a/drivers/net/phy/spi_ks8995.c b/drivers/net/phy/spi_ks8995.c index 8258c166a767..9dcc5b4fd9d1 100644 --- a/drivers/net/phy/spi_ks8995.c +++ b/drivers/net/phy/spi_ks8995.c @@ -105,6 +105,8 @@ struct ks8995_chip_params { int family_id; int chip_id; int regs_size; + int addr_width; + int addr_shift; }; static const struct ks8995_chip_params ks8995_chip[] = { @@ -113,12 +115,16 @@ static const struct ks8995_chip_params ks8995_chip[] = { .family_id = FAMILY_KS8995, .chip_id = KS8995_CHIP_ID, .regs_size = KS8995_REGS_SIZE, + .addr_width = 8, + .addr_shift = 0, }, [ksz8864] = { .name = "KSZ8864RMN", .family_id = FAMILY_KS8995, .chip_id = KSZ8864_CHIP_ID, .regs_size = KSZ8864_REGS_SIZE, + .addr_width = 8, + .addr_shift = 0, }, }; @@ -153,20 +159,44 @@ static inline u8 get_chip_rev(u8 val) return (val >> ID1_REVISION_S) & ID1_REVISION_M; } +/* create_spi_cmd - create a chip specific SPI command header + * @ks: pointer to switch instance + * @cmd: SPI command for switch + * @address: register address for command + * + * Different chip families use different bit pattern to address the switches + * registers: + * + * KS8995: 8bit command + 8bit address + * KSZ8795: 3bit command + 12bit address + 1bit TR (?) + */ +static inline __be16 create_spi_cmd(struct ks8995_switch *ks, int cmd, + unsigned address) +{ + u16 result = cmd; + + /* make room for address (incl. address shift) */ + result <<= ks->chip->addr_width + ks->chip->addr_shift; + /* add address */ + result |= address << ks->chip->addr_shift; + /* SPI protocol needs big endian */ + return cpu_to_be16(result); +} /* ------------------------------------------------------------------------ */ static int ks8995_read(struct ks8995_switch *ks, char *buf, unsigned offset, size_t count) { - u8 cmd[2]; + __be16 cmd; struct spi_transfer t[2]; struct spi_message m; int err; + cmd = create_spi_cmd(ks, KS8995_CMD_READ, offset); spi_message_init(&m); memset(&t, 0, sizeof(t)); - t[0].tx_buf = cmd; + t[0].tx_buf = &cmd; t[0].len = sizeof(cmd); spi_message_add_tail(&t[0], &m); @@ -174,9 +204,6 @@ static int ks8995_read(struct ks8995_switch *ks, char *buf, t[1].len = count; spi_message_add_tail(&t[1], &m); - cmd[0] = KS8995_CMD_READ; - cmd[1] = offset; - mutex_lock(&ks->lock); err = spi_sync(ks->spi, &m); mutex_unlock(&ks->lock); @@ -184,20 +211,20 @@ static int ks8995_read(struct ks8995_switch *ks, char *buf, return err ? err : count; } - static int ks8995_write(struct ks8995_switch *ks, char *buf, unsigned offset, size_t count) { - u8 cmd[2]; + __be16 cmd; struct spi_transfer t[2]; struct spi_message m; int err; + cmd = create_spi_cmd(ks, KS8995_CMD_WRITE, offset); spi_message_init(&m); memset(&t, 0, sizeof(t)); - t[0].tx_buf = cmd; + t[0].tx_buf = &cmd; t[0].len = sizeof(cmd); spi_message_add_tail(&t[0], &m); @@ -205,9 +232,6 @@ static int ks8995_write(struct ks8995_switch *ks, char *buf, t[1].len = count; spi_message_add_tail(&t[1], &m); - cmd[0] = KS8995_CMD_WRITE; - cmd[1] = offset; - mutex_lock(&ks->lock); err = spi_sync(ks->spi, &m); mutex_unlock(&ks->lock); -- 2.34.1