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SubjectRe: [PATCH 1/3] mmc: sdhci: introduce sdhci_compute_clock_config
From
On 4 April 2016 at 16:00, Ludovic Desroches <ludovic.desroches@atmel.com> wrote:
> In order to remove the SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST and to
> reduce code duplication, put the code relative to the SD clock
> configuration in a function which can be used by hosts for the
> implementation of the set_clock() callback.

I like this as it moves the code into the "library direction".

>
> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
> ---
> drivers/mmc/host/sdhci.c | 43 ++++++++++++++++++++++++++-----------------
> drivers/mmc/host/sdhci.h | 2 ++
> 2 files changed, 28 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 6bd3d17..ee095df 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1091,34 +1091,24 @@ static u16 sdhci_get_preset_value(struct sdhci_host *host)
> return preset;
> }
>
> -void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
> +void sdhci_compute_clock_config(struct sdhci_host *host, unsigned int clock,
> + u16 *clk_reg)

I would prefer that the value is returned as the result, instead of
providing it as an out-parameter.

> {
> int div = 0; /* Initialized for compiler warning */
> int real_div = div, clk_mul = 1;
> - u16 clk = 0;
> - unsigned long timeout;
> bool switch_base_clk = false;
>
> - host->mmc->actual_clock = 0;
> -
> - sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
> - if (host->quirks2 & SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST)
> - mdelay(1);
> -
> - if (clock == 0)
> - return;
> -
> if (host->version >= SDHCI_SPEC_300) {
> if (host->preset_enabled) {
> u16 pre_val;
>
> - clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> + *clk_reg = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
> pre_val = sdhci_get_preset_value(host);
> div = (pre_val & SDHCI_PRESET_SDCLK_FREQ_MASK)
> >> SDHCI_PRESET_SDCLK_FREQ_SHIFT;
> if (host->clk_mul &&
> (pre_val & SDHCI_PRESET_CLKGEN_SEL_MASK)) {
> - clk = SDHCI_PROG_CLOCK_MODE;
> + *clk_reg = SDHCI_PROG_CLOCK_MODE;
> real_div = div + 1;
> clk_mul = host->clk_mul;
> } else {
> @@ -1142,7 +1132,7 @@ void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
> * Set Programmable Clock Mode in the Clock
> * Control register.
> */
> - clk = SDHCI_PROG_CLOCK_MODE;
> + *clk_reg = SDHCI_PROG_CLOCK_MODE;
> real_div = div;
> clk_mul = host->clk_mul;
> div--;
> @@ -1185,9 +1175,28 @@ void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
> clock_set:
> if (real_div)
> host->mmc->actual_clock = (host->max_clk * clk_mul) / real_div;
> - clk |= (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
> - clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIV_MASK_LEN)
> + *clk_reg |= (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
> + *clk_reg |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIV_MASK_LEN)
> << SDHCI_DIVIDER_HI_SHIFT;
> +}
> +EXPORT_SYMBOL_GPL(sdhci_compute_clock_config);
> +
> +void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
> +{
> + u16 clk = 0;
> + unsigned long timeout;
> +
> + host->mmc->actual_clock = 0;
> +
> + sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
> + if (host->quirks2 & SDHCI_QUIRK2_NEED_DELAY_AFTER_INT_CLK_RST)
> + mdelay(1);
> +
> + if (clock == 0)
> + return;
> +
> + sdhci_compute_clock_config(host, clock, &clk);
> +
> clk |= SDHCI_CLOCK_INT_EN;
> sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
>
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 0f39f4f..4215eb7 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -661,6 +661,8 @@ static inline bool sdhci_sdio_irq_enabled(struct sdhci_host *host)
> return !!(host->flags & SDHCI_SDIO_IRQ_ENABLED);
> }
>
> +void sdhci_compute_clock_config(struct sdhci_host *host, unsigned int clock,
> + u16 *clk_reg);
> void sdhci_set_clock(struct sdhci_host *host, unsigned int clock);
> void sdhci_set_power(struct sdhci_host *host, unsigned char mode,
> unsigned short vdd);
> --
> 2.5.0
>

Kind regards
Uffe

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