This patch adds non-continuous clock mode support
Clock mode on Clock Lane is continuous clock by default.
So if we want to transmit data in non-continuous clock mode
to reduce power consumption, then host driver should set
DSIM_CLKLANE_STOP bit. In this case, host controller turns off
HS clock between high speed transmissions.
For this, this patch adds a new bit, DSIM_CLKLANE_STOP, and makes
the host driver set this bit only in case that dsi->mode_flags has
MIPI_DSI_CLOCK_NON_CONTINUOUS flag.
Signed-off-by: Inki Dae <inki.dae at samsung.com>
---
drivers/gpu/drm/exynos/exynos_drm_dsi.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
index 442aa2d..2d47290 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
@@ -114,6 +114,8 @@
#define DSIM_SYNC_INFORM (1 << 27)
#define DSIM_EOT_DISABLE (1 << 28)
#define DSIM_MFLUSH_VS (1 << 29)
+/* This flag is valid only for exynos3250/3472/4415/5260/5430 */
+#define DSIM_CLKLANE_STOP (1 << 30)
/* DSIM_ESCMODE */
#define DSIM_TX_TRIGGER_RST (1 << 4)
@@ -262,6 +264,7 @@ struct exynos_dsi_driver_data {
unsigned int plltmr_reg;
unsigned int has_freqband:1;
+ unsigned int has_clklane_stop:1;
};
struct exynos_dsi {
@@ -304,6 +307,7 @@ struct exynos_dsi {
static struct exynos_dsi_driver_data exynos4_dsi_driver_data = {
.plltmr_reg = 0x50,
.has_freqband = 1,
+ .has_clklane_stop = 1,
};
static struct exynos_dsi_driver_data exynos5_dsi_driver_data = {
@@ -569,6 +573,7 @@ static void exynos_dsi_disable_clock(struct exynos_dsi *dsi)
static int exynos_dsi_init_link(struct exynos_dsi *dsi)
{
+ struct exynos_dsi_driver_data *driver_data = dsi->driver_data;
int timeout;
u32 reg;
u32 lanes_mask;
@@ -650,6 +655,20 @@ static int exynos_dsi_init_link(struct exynos_dsi *dsi)
reg |= DSIM_LANE_EN(lanes_mask);
writel(reg, dsi->reg_base + DSIM_CONFIG_REG);
+ /*
+ * Use non-continuous clock mode if the periparal wants and
+ * host controller supports
+ *
+ * In non-continous clock mode, host controller will turn off
+ * the HS clock between high-speed transmissions to reduce
+ * power consumption.
+ */
+ if (driver_data->has_clklane_stop &&
+ dsi->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) {
+ reg |= DSIM_CLKLANE_STOP;
+ writel(reg, dsi->reg_base + DSIM_CONFIG_REG);
+ }
+
/* Check clock and data lane state are stop state */
timeout = 100;
do {
--
1.7.9.5
