| Message ID | 1414651017-3545-3-git-send-email-sbranden@broadcom.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 10/30/2014 12:36 AM, Scott Branden wrote: > Make the shift calculations consistent rather than having different > implementations to calculate the same thing. > diff --git a/drivers/mmc/host/sdhci-bcm2835.c b/drivers/mmc/host/sdhci-bcm2835.c > +#define REG_OFFSET_IN_BITS(reg) ((reg) << 3 & 0x18) This should really be the following so people don't have to memorize operator precedence: #define REG_OFFSET_IN_BITS(reg) (((reg) << 3) & 0x18) (I've been bit by people mis-remembering precedence in very similar code...) -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 14-11-04 08:48 PM, Stephen Warren wrote: > On 10/30/2014 12:36 AM, Scott Branden wrote: >> Make the shift calculations consistent rather than having different >> implementations to calculate the same thing. > >> diff --git a/drivers/mmc/host/sdhci-bcm2835.c b/drivers/mmc/host/sdhci-bcm2835.c > >> +#define REG_OFFSET_IN_BITS(reg) ((reg) << 3 & 0x18) > > This should really be the following so people don't have to memorize > operator precedence: > > #define REG_OFFSET_IN_BITS(reg) (((reg) << 3) & 0x18) > > (I've been bit by people mis-remembering precedence in very similar code...) > Good idea. -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/host/sdhci-bcm2835.c b/drivers/mmc/host/sdhci-bcm2835.c index c8ee02c..b6cb365 100644 --- a/drivers/mmc/host/sdhci-bcm2835.c +++ b/drivers/mmc/host/sdhci-bcm2835.c @@ -54,6 +54,8 @@ struct bcm2835_sdhci { u32 shadow; }; +#define REG_OFFSET_IN_BITS(reg) ((reg) << 3 & 0x18) + static inline u32 bcm2835_sdhci_readl(struct sdhci_host *host, int reg) { u32 val = readl(host->ioaddr + reg); @@ -67,20 +69,14 @@ static inline u32 bcm2835_sdhci_readl(struct sdhci_host *host, int reg) static u16 bcm2835_sdhci_readw(struct sdhci_host *host, int reg) { u32 val = bcm2835_sdhci_readl(host, (reg & ~3)); - u32 word_num = (reg >> 1) & 1; - u32 word_shift = word_num * 16; - u32 word = (val >> word_shift) & 0xffff; - + u16 word = val >> REG_OFFSET_IN_BITS(reg) & 0xffff; return word; } static u8 bcm2835_sdhci_readb(struct sdhci_host *host, int reg) { u32 val = bcm2835_sdhci_readl(host, (reg & ~3)); - u32 byte_num = reg & 3; - u32 byte_shift = byte_num * 8; - u32 byte = (val >> byte_shift) & 0xff; - + u8 byte = val >> REG_OFFSET_IN_BITS(reg) & 0xff; return byte; } @@ -98,8 +94,7 @@ static void bcm2835_sdhci_writew(struct sdhci_host *host, u16 val, int reg) struct bcm2835_sdhci *bcm2835_host = pltfm_host->priv; u32 oldval = (reg == SDHCI_COMMAND) ? bcm2835_host->shadow : bcm2835_sdhci_readl(host, reg & ~3); - u32 word_num = (reg >> 1) & 1; - u32 word_shift = word_num * 16; + u32 word_shift = REG_OFFSET_IN_BITS(reg); u32 mask = 0xffff << word_shift; u32 newval = (oldval & ~mask) | (val << word_shift); @@ -112,8 +107,7 @@ static void bcm2835_sdhci_writew(struct sdhci_host *host, u16 val, int reg) static void bcm2835_sdhci_writeb(struct sdhci_host *host, u8 val, int reg) { u32 oldval = bcm2835_sdhci_readl(host, reg & ~3); - u32 byte_num = reg & 3; - u32 byte_shift = byte_num * 8; + u32 byte_shift = REG_OFFSET_IN_BITS(reg); u32 mask = 0xff << byte_shift; u32 newval = (oldval & ~mask) | (val << byte_shift);
Make the shift calculations consistent rather than having different implementations to calculate the same thing. Signed-off-by: Scott Branden <sbranden@broadcom.com> --- drivers/mmc/host/sdhci-bcm2835.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-)