Le 07/07/2015 19:16, Boris Brezillon a écrit :
> Some HLCDC registers cannot be written until the hardware has finished
> applying the previous configuration request. If they are written while
> an action is still in progress, the new configuration might be silently
> ignored, resulting in unpredictable behavior.
>
> Hide the config synchronization stuff in a regmap implementation and use
> this implementation instead of the generic mmio one.
>
> Signed-off-by: Boris Brezillon <boris.brezil...@free-electrons.com>
Yes, that implements the needed behavior for these registers...
Acked-by: Nicolas Ferre <nicolas.fe...@atmel.com>
Thanks. Bye,
> ---
> Changes since v2:
> - reword the commit message
>
> Changes since v1:
> - add a 100 usec timeout
> ---
> drivers/mfd/atmel-hlcdc.c | 35 +++++++++++++++++++++++++++++++++--
> 1 file changed, 33 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mfd/atmel-hlcdc.c b/drivers/mfd/atmel-hlcdc.c
> index cfd58f4..04e01cc 100644
> --- a/drivers/mfd/atmel-hlcdc.c
> +++ b/drivers/mfd/atmel-hlcdc.c
> @@ -18,6 +18,7 @@
> */
>
> #include <linux/clk.h>
> +#include <linux/iopoll.h>
> #include <linux/mfd/atmel-hlcdc.h>
> #include <linux/mfd/core.h>
> #include <linux/module.h>
> @@ -37,11 +38,41 @@ static const struct mfd_cell atmel_hlcdc_cells[] = {
> },
> };
>
> +static int regmap_atmel_hlcdc_reg_write(void *context, unsigned int reg,
> + unsigned int val)
> +{
> + void __iomem *regs = context;
> +
> + if (reg <= ATMEL_HLCDC_DIS) {
> + u32 status;
> +
> + readl_poll_timeout(regs + ATMEL_HLCDC_SR, status,
> + !(status & ATMEL_HLCDC_SIP), 1, 100);
> + }
> +
> + writel(val, regs + reg);
> +
> + return 0;
> +}
> +
> +static int regmap_atmel_hlcdc_reg_read(void *context, unsigned int reg,
> + unsigned int *val)
> +{
> + void __iomem *regs = context;
> +
> + *val = readl(regs + reg);
> +
> + return 0;
> +}
> +
> static const struct regmap_config atmel_hlcdc_regmap_config = {
> .reg_bits = 32,
> .val_bits = 32,
> .reg_stride = 4,
> .max_register = ATMEL_HLCDC_REG_MAX,
> + .reg_write = regmap_atmel_hlcdc_reg_write,
> + .reg_read = regmap_atmel_hlcdc_reg_read,
> + .fast_io = true,
> };
>
> static int atmel_hlcdc_probe(struct platform_device *pdev)
> @@ -82,8 +113,8 @@ static int atmel_hlcdc_probe(struct platform_device *pdev)
> return PTR_ERR(hlcdc->slow_clk);
> }
>
> - hlcdc->regmap = devm_regmap_init_mmio(dev, regs,
> - &atmel_hlcdc_regmap_config);
> + hlcdc->regmap = devm_regmap_init(dev, NULL, regs,
> + &atmel_hlcdc_regmap_config);
> if (IS_ERR(hlcdc->regmap))
> return PTR_ERR(hlcdc->regmap);
>
>
--
Nicolas Ferre
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