[Intel-gfx] [BXT MIPI PATCH v4 07/14] drm/i915/bxt: Program Tx Rx and Dphy clocks
Uma Shankar
uma.shankar at intel.com
Wed Sep 23 10:57:17 PDT 2015
From: Shashank Sharma <shashank.sharma at intel.com>
BXT DSI clocks are different than previous platforms. So adding a
new function to program following clocks and dividers:
1. Program variable divider to generate input to Tx clock divider
(Output value must be < 39.5Mhz)
2. Select divide by 2 option to get < 20Mhz for Tx clock
3. Program 8by3 divider to generate Rx clock
v2: Fixed Jani's review comments. Adjusted the Macro definition as
per convention. Simplified the logic for bit definitions for
MIPI PORT A and PORT C in same registers.
v3: Refactored the macros for TX, RX Escape and DPHY clocks as per
Jani's suggestion.
v4: Addressed Jani's review comments.
Signed-off-by: Shashank Sharma <shashank.sharma at intel.com>
Signed-off-by: Uma Shankar <uma.shankar at intel.com>
---
drivers/gpu/drm/i915/i915_reg.h | 62 ++++++++++++++++++++++++++++++++++
drivers/gpu/drm/i915/intel_dsi_pll.c | 42 +++++++++++++++++++++++
2 files changed, 104 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 57c5dbf..88a16e2 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -7362,6 +7362,68 @@ enum skl_disp_power_wells {
#define _MIPI_PORT(port, a, c) _PORT3(port, a, 0, c) /* ports A and C only */
+/* BXT MIPI clock controls */
+#define BXT_MAX_VAR_OUTPUT_KHZ 39500
+
+#define BXT_MIPI_CLOCK_CTL 0x46090
+#define BXT_MIPI1_DIV_SHIFT 26
+#define BXT_MIPI2_DIV_SHIFT 10
+#define BXT_MIPI_DIV_SHIFT(port) \
+ _MIPI_PORT(port, BXT_MIPI1_DIV_SHIFT, \
+ BXT_MIPI2_DIV_SHIFT)
+/* Var clock divider to generate TX source. Result must be < 39.5 M */
+#define BXT_MIPI1_ESCLK_VAR_DIV_MASK (0x3F << 26)
+#define BXT_MIPI2_ESCLK_VAR_DIV_MASK (0x3F << 10)
+#define BXT_MIPI_ESCLK_VAR_DIV_MASK(port) \
+ _MIPI_PORT(port, BXT_MIPI1_ESCLK_VAR_DIV_MASK, \
+ BXT_MIPI2_ESCLK_VAR_DIV_MASK)
+
+#define BXT_MIPI_ESCLK_VAR_DIV(port, val) \
+ (val << BXT_MIPI_DIV_SHIFT(port))
+/* TX control divider to select actual TX clock output from (8x/var) */
+#define BXT_MIPI1_TX_ESCLK_SHIFT 21
+#define BXT_MIPI2_TX_ESCLK_SHIFT 5
+#define BXT_MIPI_TX_ESCLK_SHIFT(port) \
+ _MIPI_PORT(port, BXT_MIPI1_TX_ESCLK_SHIFT, \
+ BXT_MIPI2_TX_ESCLK_SHIFT)
+#define BXT_MIPI1_TX_ESCLK_FIXDIV_MASK (3 << 21)
+#define BXT_MIPI2_TX_ESCLK_FIXDIV_MASK (3 << 5)
+#define BXT_MIPI_TX_ESCLK_FIXDIV_MASK(port) \
+ _MIPI_PORT(port, BXT_MIPI1_TX_ESCLK_FIXDIV_MASK, \
+ BXT_MIPI2_TX_ESCLK_FIXDIV_MASK)
+#define BXT_MIPI_TX_ESCLK_8XDIV_BY2(port) \
+ (0x0 << BXT_MIPI_TX_ESCLK_SHIFT(port))
+#define BXT_MIPI_TX_ESCLK_8XDIV_BY4(port) \
+ (0x1 << BXT_MIPI_TX_ESCLK_SHIFT(port))
+#define BXT_MIPI_TX_ESCLK_8XDIV_BY8(port) \
+ (0x2 << BXT_MIPI_TX_ESCLK_SHIFT(port))
+/* RX control divider to select actual RX clock output from 8x*/
+#define BXT_MIPI1_RX_ESCLK_SHIFT 19
+#define BXT_MIPI2_RX_ESCLK_SHIFT 3
+#define BXT_MIPI_RX_ESCLK_SHIFT(port) \
+ _MIPI_PORT(port, BXT_MIPI1_RX_ESCLK_SHIFT, \
+ BXT_MIPI2_RX_ESCLK_SHIFT)
+#define BXT_MIPI1_RX_ESCLK_FIXDIV_MASK (3 << 19)
+#define BXT_MIPI2_RX_ESCLK_FIXDIV_MASK (3 << 3)
+#define BXT_MIPI_RX_ESCLK_FIXDIV_MASK(port) \
+ (3 << BXT_MIPI_RX_ESCLK_SHIFT(port))
+#define BXT_MIPI_RX_ESCLK_8X_BY2(port) \
+ (1 << BXT_MIPI_RX_ESCLK_SHIFT(port))
+#define BXT_MIPI_RX_ESCLK_8X_BY3(port) \
+ (2 << BXT_MIPI_RX_ESCLK_SHIFT(port))
+#define BXT_MIPI_RX_ESCLK_8X_BY4(port) \
+ (3 << BXT_MIPI_RX_ESCLK_SHIFT(port))
+/* BXT-A WA: Always prog DPHY dividers to 00 */
+#define BXT_MIPI1_DPHY_DIV_SHIFT 16
+#define BXT_MIPI2_DPHY_DIV_SHIFT 0
+#define BXT_MIPI_DPHY_DIV_SHIFT(port) \
+ _MIPI_PORT(port, BXT_MIPI1_DPHY_DIV_SHIFT, \
+ BXT_MIPI2_DPHY_DIV_SHIFT)
+#define BXT_MIPI_1_DPHY_DIVIDER_MASK (3 << 16)
+#define BXT_MIPI_2_DPHY_DIVIDER_MASK (3 << 0)
+#define BXT_MIPI_DPHY_DIVIDER_MASK(port) \
+ (3 << BXT_MIPI_DPHY_DIV_SHIFT(port))
+
/* BXT MIPI mode configure */
#define _BXT_MIPIA_TRANS_HACTIVE 0x6B0F8
#define _BXT_MIPIC_TRANS_HACTIVE 0x6B8F8
diff --git a/drivers/gpu/drm/i915/intel_dsi_pll.c b/drivers/gpu/drm/i915/intel_dsi_pll.c
index 21a2e37..e62729f 100644
--- a/drivers/gpu/drm/i915/intel_dsi_pll.c
+++ b/drivers/gpu/drm/i915/intel_dsi_pll.c
@@ -389,6 +389,42 @@ u32 vlv_get_dsi_pclk(struct intel_encoder *encoder, int pipe_bpp)
return pclk;
}
+/* Program BXT Mipi clocks and dividers */
+static void bxt_dsi_program_clocks(struct drm_device *dev, enum port port)
+{
+ u32 tmp;
+ u32 divider;
+ u32 dsi_rate;
+ u32 pll_ratio;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ /* Clear old configurations */
+ tmp = I915_READ(BXT_MIPI_CLOCK_CTL);
+ tmp &= ~(BXT_MIPI_TX_ESCLK_FIXDIV_MASK(port));
+ tmp &= ~(BXT_MIPI_RX_ESCLK_FIXDIV_MASK(port));
+ tmp &= ~(BXT_MIPI_ESCLK_VAR_DIV_MASK(port));
+ tmp &= ~(BXT_MIPI_DPHY_DIVIDER_MASK(port));
+
+ /* Get the current DSI rate(actual) */
+ pll_ratio = I915_READ(BXT_DSI_PLL_CTL) &
+ BXT_DSI_PLL_RATIO_MASK;
+ dsi_rate = (BXT_REF_CLOCK_KHZ * pll_ratio) / 2;
+
+ /* Max possible output of clock is 39.5 MHz, program value -1 */
+ divider = (dsi_rate / BXT_MAX_VAR_OUTPUT_KHZ) - 1;
+ tmp |= BXT_MIPI_ESCLK_VAR_DIV(port, divider);
+
+ /*
+ * Tx escape clock must be as close to 20MHz possible, but should
+ * not exceed it. Hence select divide by 2
+ */
+ tmp |= BXT_MIPI_TX_ESCLK_8XDIV_BY2(port);
+
+ tmp |= BXT_MIPI_RX_ESCLK_8X_BY3(port);
+
+ I915_WRITE(BXT_MIPI_CLOCK_CTL, tmp);
+}
+
static bool bxt_configure_dsi_pll(struct intel_encoder *encoder)
{
struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
@@ -440,6 +476,8 @@ static bool bxt_configure_dsi_pll(struct intel_encoder *encoder)
static void bxt_enable_dsi_pll(struct intel_encoder *encoder)
{
struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
+ struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
+ enum port port;
u32 val;
DRM_DEBUG_KMS("\n");
@@ -458,6 +496,10 @@ static void bxt_enable_dsi_pll(struct intel_encoder *encoder)
return;
}
+ /* Program TX, RX, Dphy clocks */
+ for_each_dsi_port(port, intel_dsi->ports)
+ bxt_dsi_program_clocks(encoder->base.dev, port);
+
/* Enable DSI PLL */
val = I915_READ(BXT_DSI_PLL_ENABLE);
val |= BXT_DSI_PLL_DO_ENABLE;
--
1.7.9.5
More information about the Intel-gfx
mailing list