[PATCH v2 2/3] spi: meson-axg: enhance output enable feature

[Sunny Luo]

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