The SPICC controller in Meson-AXG is capable of driving the CLK/MOSI/SS signal lines through the idle state (between two transmission operation), which avoid the signals floating in unexpected state.
Signed-off-by: Sunny Luo <sunny....@amlogic.com> Signed-off-by: Yixun Lan <yixun....@amlogic.com> --- drivers/spi/spi-meson-spicc.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi-meson-spicc.c b/drivers/spi/spi-meson-spicc.c index b56249d..0384c28 100644 --- a/drivers/spi/spi-meson-spicc.c +++ b/drivers/spi/spi-meson-spicc.c @@ -115,6 +115,13 @@ #define SPICC_DWADDR 0x24 /* Write Address of DMA */ +#define SPICC_ENH_CTL0 0x38 /* Enhanced Feature */ +#define SPICC_ENH_MOSI_OEN BIT(25) +#define SPICC_ENH_CLK_OEN BIT(26) +#define SPICC_ENH_CS_OEN BIT(27) +#define SPICC_ENH_CLK_CS_DELAY_EN BIT(28) +#define SPICC_ENH_MAIN_CLK_AO BIT(29) + #define writel_bits_relaxed(mask, val, addr) \ writel_relaxed((readl_relaxed(addr) & ~(mask)) | (val), addr) @@ -123,6 +130,7 @@ struct meson_spicc_data { unsigned int max_speed_hz; + bool has_oen; }; struct meson_spicc_device { @@ -145,6 +153,19 @@ struct meson_spicc_device { bool is_last_burst; }; +static void meson_spicc_oen_enable(struct meson_spicc_device *spicc) +{ + u32 conf; + + if (!spicc->data->has_oen) + return; + + conf = readl_relaxed(spicc->base + SPICC_ENH_CTL0) | + SPICC_ENH_MOSI_OEN | SPICC_ENH_CLK_OEN | SPICC_ENH_CS_OEN; + + writel_relaxed(conf, spicc->base + SPICC_ENH_CTL0); +} + static inline bool meson_spicc_txfull(struct meson_spicc_device *spicc) { return !!FIELD_GET(SPICC_TF, @@ -453,6 +474,8 @@ static int meson_spicc_prepare_message(struct spi_master *master, writel_bits_relaxed(BIT(24), BIT(24), spicc->base + SPICC_TESTREG); + meson_spicc_oen_enable(spicc); + return 0; } @@ -610,11 +633,12 @@ static int meson_spicc_remove(struct platform_device *pdev) } static const struct meson_spicc_data meson_spicc_gx_data = { - .max_speed_hz = 30000000, + .max_speed_hz = 30000000, }; static const struct meson_spicc_data meson_spicc_axg_data = { - .max_speed_hz = 80000000, + .max_speed_hz = 80000000, + .has_oen = true, }; static const struct of_device_id meson_spicc_of_match[] = { -- 2.7.4