On Thu, May 21, 2020 at 12:03:58PM -0500, Dinh Nguyen wrote:
> Add mechanism to get the reset control and deassert it in order to bring
> the IP out of reset.
>
> Signed-off-by: Liang Jin J <liang.j.jin@xxxxxxxxxxxx>
> Signed-off-by: Dinh Nguyen <dinguyen@xxxxxxxxxx>
Is the From: correct here?
Also adding everyone else who's got patches in flight for this driver
right now.
> ---
> drivers/spi/spi-dw-mmio.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
> index 384a3ab6dc2d..5c813e15ed89 100644
> --- a/drivers/spi/spi-dw-mmio.c
> +++ b/drivers/spi/spi-dw-mmio.c
> @@ -20,6 +20,7 @@
> #include <linux/acpi.h>
> #include <linux/property.h>
> #include <linux/regmap.h>
> +#include <linux/reset.h>
>
> #include "spi-dw.h"
>
> @@ -30,6 +31,7 @@ struct dw_spi_mmio {
> struct clk *clk;
> struct clk *pclk;
> void *priv;
> + struct reset_control *rstc;
> };
>
> #define MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL 0x24
> @@ -145,6 +147,10 @@ static int dw_spi_mmio_probe(struct platform_device *pdev)
> if (!dwsmmio)
> return -ENOMEM;
>
> + dwsmmio->rstc = devm_reset_control_get_exclusive(&pdev->dev, "spi");
> + if (!IS_ERR(dwsmmio->rstc))
> + reset_control_deassert(dwsmmio->rstc);
> +
> dws = &dwsmmio->dws;
>
> /* Get basic io resource and map it */
Should we also undo the reset in error paths from probe()? It's not the
end of the world if we don't but...
> @@ -220,6 +226,9 @@ static int dw_spi_mmio_remove(struct platform_device *pdev)
> clk_disable_unprepare(dwsmmio->pclk);
> clk_disable_unprepare(dwsmmio->clk);
>
> + if (dwsmmio->rstc)
> + reset_control_assert(dwsmmio->rstc);
> +
> return 0;
> }
>
> --
> 2.17.1
>
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