As some more information is added to the PCR register, we'd better use a copy of its content and modify just the peripheral-related bits. Implement a read-modify-write for the enable() and disable() callbacks.
Header file is also modified to have the PCR_DIV mask. Signed-off-by: Nicolas Ferre <[email protected]> --- drivers/clk/at91/clk-peripheral.c | 19 +++++++++++++------ include/linux/clk/at91_pmc.h | 3 ++- 2 files changed, 15 insertions(+), 7 deletions(-) diff --git a/drivers/clk/at91/clk-peripheral.c b/drivers/clk/at91/clk-peripheral.c index 597fed423d7d..37e2fea14890 100644 --- a/drivers/clk/at91/clk-peripheral.c +++ b/drivers/clk/at91/clk-peripheral.c @@ -161,14 +161,17 @@ static int clk_sam9x5_peripheral_enable(struct clk_hw *hw) { struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); struct at91_pmc *pmc = periph->pmc; + u32 tmp; if (periph->id < PERIPHERAL_ID_MIN) return 0; - pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID) | - AT91_PMC_PCR_CMD | - AT91_PMC_PCR_DIV(periph->div) | - AT91_PMC_PCR_EN); + pmc_lock(pmc); + pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID)); + tmp = pmc_read(pmc, AT91_PMC_PCR) & ~AT91_PMC_PCR_P_DIV; + pmc_write(pmc, AT91_PMC_PCR, tmp | AT91_PMC_PCR_PDIV(periph->div) + | AT91_PMC_PCR_EN); + pmc_unlock(pmc); return 0; } @@ -176,12 +179,16 @@ static void clk_sam9x5_peripheral_disable(struct clk_hw *hw) { struct clk_sam9x5_peripheral *periph = to_clk_sam9x5_peripheral(hw); struct at91_pmc *pmc = periph->pmc; + u32 tmp; if (periph->id < PERIPHERAL_ID_MIN) return; - pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID) | - AT91_PMC_PCR_CMD); + pmc_lock(pmc); + pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID)); + tmp = pmc_read(pmc, AT91_PMC_PCR) & ~AT91_PMC_PCR_EN; + pmc_write(pmc, AT91_PMC_PCR, tmp); + pmc_unlock(pmc); } static int clk_sam9x5_peripheral_is_enabled(struct clk_hw *hw) diff --git a/include/linux/clk/at91_pmc.h b/include/linux/clk/at91_pmc.h index 7669f7618f39..4685c3d62f94 100644 --- a/include/linux/clk/at91_pmc.h +++ b/include/linux/clk/at91_pmc.h @@ -184,7 +184,8 @@ extern void __iomem *at91_pmc_base; #define AT91_PMC_PCR 0x10c /* Peripheral Control Register [some SAM9 and SAMA5] */ #define AT91_PMC_PCR_PID (0x3f << 0) /* Peripheral ID */ #define AT91_PMC_PCR_CMD (0x1 << 12) /* Command (read=0, write=1) */ -#define AT91_PMC_PCR_DIV(n) ((n) << 16) /* Divisor Value */ +#define AT91_PMC_PCR_P_DIV (0x3 << 16) /* Divisor mask */ +#define AT91_PMC_PCR_PDIV(n) ((n) << 16) /* Divisor Value */ #define AT91_PMC_PCR_DIV0 0x0 /* Peripheral clock is MCK */ #define AT91_PMC_PCR_DIV2 0x1 /* Peripheral clock is MCK/2 */ #define AT91_PMC_PCR_DIV4 0x2 /* Peripheral clock is MCK/4 */ -- 2.1.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
