From 4a5ff99bbb8fcd4642995ef39bccc7f25e1f90d3 Mon Sep 17 00:00:00 2001 From: Emmanuel Gil Peyrot Date: Tue, 11 May 2021 23:07:24 +0200 Subject: misc: eeprom_93xx46: Remove hardcoded bit lengths MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This avoids using magic numbers based on the length of an address or a command, while we only want to differentiate between 8-bit and 16-bit. The driver was previously wrapping around the offset in the write operation, this now returns -EINVAL instead (but should never happen in the first place). If two pointer indirections are too many, we could move the flags to the main struct instead, but I doubt it’s going to make any sensible difference on any hardware. Reviewed-by: Jonathan Neuschäfer Signed-off-by: Emmanuel Gil Peyrot Link: https://lore.kernel.org/r/20210511210727.24895-2-linkmauve@linkmauve.fr Signed-off-by: Greg Kroah-Hartman --- drivers/misc/eeprom/eeprom_93xx46.c | 57 +++++++++++++++++++++---------------- 1 file changed, 32 insertions(+), 25 deletions(-) (limited to 'drivers/misc/eeprom') diff --git a/drivers/misc/eeprom/eeprom_93xx46.c b/drivers/misc/eeprom/eeprom_93xx46.c index 80114f4c80ad..ffdb8e5a26e0 100644 --- a/drivers/misc/eeprom/eeprom_93xx46.c +++ b/drivers/misc/eeprom/eeprom_93xx46.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -70,6 +71,7 @@ static int eeprom_93xx46_read(void *priv, unsigned int off, struct eeprom_93xx46_dev *edev = priv; char *buf = val; int err = 0; + int bits; if (unlikely(off >= edev->size)) return 0; @@ -83,21 +85,21 @@ static int eeprom_93xx46_read(void *priv, unsigned int off, if (edev->pdata->prepare) edev->pdata->prepare(edev); + /* The opcode in front of the address is three bits. */ + bits = edev->addrlen + 3; + while (count) { struct spi_message m; struct spi_transfer t[2] = { { 0 } }; u16 cmd_addr = OP_READ << edev->addrlen; size_t nbytes = count; - int bits; - if (edev->addrlen == 7) { - cmd_addr |= off & 0x7f; - bits = 10; + if (edev->pdata->flags & EE_ADDR8) { + cmd_addr |= off; if (has_quirk_single_word_read(edev)) nbytes = 1; } else { - cmd_addr |= (off >> 1) & 0x3f; - bits = 9; + cmd_addr |= (off >> 1); if (has_quirk_single_word_read(edev)) nbytes = 2; } @@ -152,14 +154,14 @@ static int eeprom_93xx46_ew(struct eeprom_93xx46_dev *edev, int is_on) int bits, ret; u16 cmd_addr; + /* The opcode in front of the address is three bits. */ + bits = edev->addrlen + 3; + cmd_addr = OP_START << edev->addrlen; - if (edev->addrlen == 7) { + if (edev->pdata->flags & EE_ADDR8) cmd_addr |= (is_on ? ADDR_EWEN : ADDR_EWDS) << 1; - bits = 10; - } else { + else cmd_addr |= (is_on ? ADDR_EWEN : ADDR_EWDS); - bits = 9; - } if (has_quirk_instruction_length(edev)) { cmd_addr <<= 2; @@ -205,15 +207,19 @@ eeprom_93xx46_write_word(struct eeprom_93xx46_dev *edev, int bits, data_len, ret; u16 cmd_addr; + if (unlikely(off >= edev->size)) + return -EINVAL; + + /* The opcode in front of the address is three bits. */ + bits = edev->addrlen + 3; + cmd_addr = OP_WRITE << edev->addrlen; - if (edev->addrlen == 7) { - cmd_addr |= off & 0x7f; - bits = 10; + if (edev->pdata->flags & EE_ADDR8) { + cmd_addr |= off; data_len = 1; } else { - cmd_addr |= (off >> 1) & 0x3f; - bits = 9; + cmd_addr |= (off >> 1); data_len = 2; } @@ -253,7 +259,7 @@ static int eeprom_93xx46_write(void *priv, unsigned int off, return count; /* only write even number of bytes on 16-bit devices */ - if (edev->addrlen == 6) { + if (edev->pdata->flags & EE_ADDR16) { step = 2; count &= ~1; } @@ -295,14 +301,14 @@ static int eeprom_93xx46_eral(struct eeprom_93xx46_dev *edev) int bits, ret; u16 cmd_addr; + /* The opcode in front of the address is three bits. */ + bits = edev->addrlen + 3; + cmd_addr = OP_START << edev->addrlen; - if (edev->addrlen == 7) { + if (edev->pdata->flags & EE_ADDR8) cmd_addr |= ADDR_ERAL << 1; - bits = 10; - } else { + else cmd_addr |= ADDR_ERAL; - bits = 9; - } if (has_quirk_instruction_length(edev)) { cmd_addr <<= 2; @@ -455,10 +461,12 @@ static int eeprom_93xx46_probe(struct spi_device *spi) if (!edev) return -ENOMEM; + edev->size = 128; + if (pd->flags & EE_ADDR8) - edev->addrlen = 7; + edev->addrlen = ilog2(edev->size); else if (pd->flags & EE_ADDR16) - edev->addrlen = 6; + edev->addrlen = ilog2(edev->size) - 1; else { dev_err(&spi->dev, "unspecified address type\n"); return -EINVAL; @@ -469,7 +477,6 @@ static int eeprom_93xx46_probe(struct spi_device *spi) edev->spi = spi; edev->pdata = pd; - edev->size = 128; edev->nvmem_config.type = NVMEM_TYPE_EEPROM; edev->nvmem_config.name = dev_name(&spi->dev); edev->nvmem_config.dev = &spi->dev; -- cgit v1.2.3