On Wed, 17 Jun 2015 14:40:39 +0200
Nicolas Ferre <nicolas.fe...@atmel.com> wrote:
> 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.
>
> Signed-off-by: Nicolas Ferre <nicolas.fe...@atmel.com>
Acked-by: Boris Brezillon <boris.brezil...@free-electrons.com>
> ---
> v2: - modify header file beforehand so that we can use consistent field naming
>
>
> drivers/clk/at91/clk-peripheral.c | 20 ++++++++++++++------
> 1 file changed, 14 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/clk/at91/clk-peripheral.c
> b/drivers/clk/at91/clk-peripheral.c
> index 61d0adda7088..1e7dcc57925a 100644
> --- a/drivers/clk/at91/clk-peripheral.c
> +++ b/drivers/clk/at91/clk-peripheral.c
> @@ -161,14 +161,18 @@ 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_MASK) |
> - 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_MASK));
> + tmp = pmc_read(pmc, AT91_PMC_PCR) & ~AT91_PMC_PCR_DIV_MASK;
> + pmc_write(pmc, AT91_PMC_PCR, tmp | AT91_PMC_PCR_DIV(periph->div)
> + | AT91_PMC_PCR_CMD
> + | AT91_PMC_PCR_EN);
> + pmc_unlock(pmc);
> return 0;
> }
>
> @@ -176,12 +180,16 @@ 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_MASK) |
> - AT91_PMC_PCR_CMD);
> + pmc_lock(pmc);
> + pmc_write(pmc, AT91_PMC_PCR, (periph->id & AT91_PMC_PCR_PID_MASK));
> + tmp = pmc_read(pmc, AT91_PMC_PCR) & ~AT91_PMC_PCR_EN;
> + pmc_write(pmc, AT91_PMC_PCR, tmp | AT91_PMC_PCR_CMD);
> + pmc_unlock(pmc);
> }
>
> static int clk_sam9x5_peripheral_is_enabled(struct clk_hw *hw)
--
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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