drm/i915: add VLV DSI PLL Calculations

v2:
 - Grab dpio_lock mutex in vlv_enable_dsi_pll().
 - Add and call vlv_disable_dsi_pll().

v3: Mostly based on Ville's review comments.
 - Only pipe A has DSI PLL lock bit.
 - Add more of CCK REG bit definitions for DSI PLL.
 - Make tables static.
 - Move clock gating out of the clock calculation functions.
 - DSI PLL LDO power gating.
 - Put alternative MNP from table calc behind #ifdef.

v4: s/CKK/CLK/ in the CCK REG bit definitions (Ville).

Signed-off-by: ymohanma <yogesh.mohan.marimuthu@intel.com>
Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/Makefile

@@ -23,6 +23,7 @@ i915-y := i915_drv.o i915_dma.o i915_irq.o \
 	  intel_lvds.o \
 	  intel_dsi.o \
 	  intel_dsi_cmd.o \
+	  intel_dsi_pll.o \
 	  intel_bios.o \
 	  intel_ddi.o \
 	  intel_dp.o \

drivers/gpu/drm/i915/i915_reg.h

@@ -376,6 +376,38 @@
 #define   FB_FMAX_VMIN_FREQ_LO_SHIFT		27
 #define   FB_FMAX_VMIN_FREQ_LO_MASK		0xf8000000
 
+/* vlv2 north clock has */
+#define CCK_REG_DSI_PLL_FUSE			0x44
+#define CCK_REG_DSI_PLL_CONTROL			0x48
+#define  DSI_PLL_VCO_EN				(1 << 31)
+#define  DSI_PLL_LDO_GATE			(1 << 30)
+#define  DSI_PLL_P1_POST_DIV_SHIFT		17
+#define  DSI_PLL_P1_POST_DIV_MASK		(0x1ff << 17)
+#define  DSI_PLL_P2_MUX_DSI0_DIV2		(1 << 13)
+#define  DSI_PLL_P3_MUX_DSI1_DIV2		(1 << 12)
+#define  DSI_PLL_MUX_MASK			(3 << 9)
+#define  DSI_PLL_MUX_DSI0_DSIPLL		(0 << 10)
+#define  DSI_PLL_MUX_DSI0_CCK			(1 << 10)
+#define  DSI_PLL_MUX_DSI1_DSIPLL		(0 << 9)
+#define  DSI_PLL_MUX_DSI1_CCK			(1 << 9)
+#define  DSI_PLL_CLK_GATE_MASK			(0xf << 5)
+#define  DSI_PLL_CLK_GATE_DSI0_DSIPLL		(1 << 8)
+#define  DSI_PLL_CLK_GATE_DSI1_DSIPLL		(1 << 7)
+#define  DSI_PLL_CLK_GATE_DSI0_CCK		(1 << 6)
+#define  DSI_PLL_CLK_GATE_DSI1_CCK		(1 << 5)
+#define  DSI_PLL_LOCK				(1 << 0)
+#define CCK_REG_DSI_PLL_DIVIDER			0x4c
+#define  DSI_PLL_LFSR				(1 << 31)
+#define  DSI_PLL_FRACTION_EN			(1 << 30)
+#define  DSI_PLL_FRAC_COUNTER_SHIFT		27
+#define  DSI_PLL_FRAC_COUNTER_MASK		(7 << 27)
+#define  DSI_PLL_USYNC_CNT_SHIFT		18
+#define  DSI_PLL_USYNC_CNT_MASK			(0x1ff << 18)
+#define  DSI_PLL_N1_DIV_SHIFT			16
+#define  DSI_PLL_N1_DIV_MASK			(3 << 16)
+#define  DSI_PLL_M1_DIV_SHIFT			0
+#define  DSI_PLL_M1_DIV_MASK			(0x1ff << 0)
+
 /*
  * DPIO - a special bus for various display related registers to hide behind
  *

drivers/gpu/drm/i915/intel_dsi.c

@@ -83,6 +83,8 @@ static bool intel_dsi_compute_config(struct intel_encoder *encoder,
 static void intel_dsi_pre_pll_enable(struct intel_encoder *encoder)
 {
 	DRM_DEBUG_KMS("\n");
+
+	vlv_enable_dsi_pll(encoder);
 }
 
 static void intel_dsi_pre_enable(struct intel_encoder *encoder)
@@ -167,6 +169,8 @@ static void intel_dsi_disable(struct intel_encoder *encoder)
 static void intel_dsi_post_disable(struct intel_encoder *encoder)
 {
 	DRM_DEBUG_KMS("\n");
+
+	vlv_disable_dsi_pll(encoder);
 }
 
 static bool intel_dsi_get_hw_state(struct intel_encoder *encoder,
@@ -303,6 +307,9 @@ static void intel_dsi_mode_set(struct intel_encoder *intel_encoder)
 
 	DRM_DEBUG_KMS("pipe %d\n", pipe);
 
+	/* Update the DSI PLL */
+	vlv_enable_dsi_pll(intel_encoder);
+
 	/* escape clock divider, 20MHz, shared for A and C. device ready must be
 	 * off when doing this! txclkesc? */
 	tmp = I915_READ(MIPI_CTRL(0));

drivers/gpu/drm/i915/intel_dsi.h

@@ -96,4 +96,7 @@ static inline struct intel_dsi *enc_to_intel_dsi(struct drm_encoder *encoder)
 	return container_of(encoder, struct intel_dsi, base.base);
 }
 
+extern void vlv_enable_dsi_pll(struct intel_encoder *encoder);
+extern void vlv_disable_dsi_pll(struct intel_encoder *encoder);
+
 #endif /* _INTEL_DSI_H */

drivers/gpu/drm/i915/intel_dsi_pll.c

@@ -0,0 +1,317 @@
+/*
+ * Copyright © 2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ *	Shobhit Kumar <shobhit.kumar@intel.com>
+ *	Yogesh Mohan Marimuthu <yogesh.mohan.marimuthu@intel.com>
+ */
+
+#include <linux/kernel.h>
+#include "intel_drv.h"
+#include "i915_drv.h"
+#include "intel_dsi.h"
+
+#define DSI_HSS_PACKET_SIZE		4
+#define DSI_HSE_PACKET_SIZE		4
+#define DSI_HSA_PACKET_EXTRA_SIZE	6
+#define DSI_HBP_PACKET_EXTRA_SIZE	6
+#define DSI_HACTIVE_PACKET_EXTRA_SIZE	6
+#define DSI_HFP_PACKET_EXTRA_SIZE	6
+#define DSI_EOTP_PACKET_SIZE		4
+
+struct dsi_mnp {
+	u32 dsi_pll_ctrl;
+	u32 dsi_pll_div;
+};
+
+static const u32 lfsr_converts[] = {
+	426, 469, 234, 373, 442, 221, 110, 311, 411,		/* 62 - 70 */
+	461, 486, 243, 377, 188, 350, 175, 343, 427, 213,	/* 71 - 80 */
+	106, 53, 282, 397, 354, 227, 113, 56, 284, 142,		/* 81 - 90 */
+	71, 35							/* 91 - 92 */
+};
+
+static u32 dsi_rr_formula(struct drm_display_mode *mode,
+			  int pixel_format, int video_mode_format,
+			  int lane_count, bool eotp)
+{
+	u32 bpp;
+	u32 hactive, vactive, hfp, hsync, hbp, vfp, vsync, vbp;
+	u32 hsync_bytes, hbp_bytes, hactive_bytes, hfp_bytes;
+	u32 bytes_per_line, bytes_per_frame;
+	u32 num_frames;
+	u32 bytes_per_x_frames, bytes_per_x_frames_x_lanes;
+	u32 dsi_bit_clock_hz;
+	u32 dsi_clk;
+
+	switch (pixel_format) {
+	default:
+	case VID_MODE_FORMAT_RGB888:
+	case VID_MODE_FORMAT_RGB666_LOOSE:
+		bpp = 24;
+		break;
+	case VID_MODE_FORMAT_RGB666:
+		bpp = 18;
+		break;
+	case VID_MODE_FORMAT_RGB565:
+		bpp = 16;
+		break;
+	}
+
+	hactive = mode->hdisplay;
+	vactive = mode->vdisplay;
+	hfp = mode->hsync_start - mode->hdisplay;
+	hsync = mode->hsync_end - mode->hsync_start;
+	hbp = mode->htotal - mode->hsync_end;
+
+	vfp = mode->vsync_start - mode->vdisplay;
+	vsync = mode->vsync_end - mode->vsync_start;
+	vbp = mode->vtotal - mode->vsync_end;
+
+	hsync_bytes = DIV_ROUND_UP(hsync * bpp, 8);
+	hbp_bytes = DIV_ROUND_UP(hbp * bpp, 8);
+	hactive_bytes = DIV_ROUND_UP(hactive * bpp, 8);
+	hfp_bytes = DIV_ROUND_UP(hfp * bpp, 8);
+
+	bytes_per_line = DSI_HSS_PACKET_SIZE + hsync_bytes +
+		DSI_HSA_PACKET_EXTRA_SIZE + DSI_HSE_PACKET_SIZE +
+		hbp_bytes + DSI_HBP_PACKET_EXTRA_SIZE +
+		hactive_bytes + DSI_HACTIVE_PACKET_EXTRA_SIZE +
+		hfp_bytes + DSI_HFP_PACKET_EXTRA_SIZE;
+
+	/*
+	 * XXX: Need to accurately calculate LP to HS transition timeout and add
+	 * it to bytes_per_line/bytes_per_frame.
+	 */
+
+	if (eotp && video_mode_format == VIDEO_MODE_BURST)
+		bytes_per_line += DSI_EOTP_PACKET_SIZE;
+
+	bytes_per_frame = vsync * bytes_per_line + vbp * bytes_per_line +
+		vactive * bytes_per_line + vfp * bytes_per_line;
+
+	if (eotp &&
+	    (video_mode_format == VIDEO_MODE_NON_BURST_WITH_SYNC_PULSE ||
+	     video_mode_format == VIDEO_MODE_NON_BURST_WITH_SYNC_EVENTS))
+		bytes_per_frame += DSI_EOTP_PACKET_SIZE;
+
+	num_frames = drm_mode_vrefresh(mode);
+	bytes_per_x_frames = num_frames * bytes_per_frame;
+
+	bytes_per_x_frames_x_lanes = bytes_per_x_frames / lane_count;
+
+	/* the dsi clock is divided by 2 in the hardware to get dsi ddr clock */
+	dsi_bit_clock_hz = bytes_per_x_frames_x_lanes * 8;
+	dsi_clk = dsi_bit_clock_hz / (1000 * 1000);
+
+	if (eotp && video_mode_format == VIDEO_MODE_BURST)
+		dsi_clk *= 2;
+
+	return dsi_clk;
+}
+
+#ifdef MNP_FROM_TABLE
+
+struct dsi_clock_table {
+	u32 freq;
+	u8 m;
+	u8 p;
+};
+
+static const struct dsi_clock_table dsi_clk_tbl[] = {
+	{300, 72, 6}, {313, 75, 6}, {323, 78, 6}, {333, 80, 6},
+	{343, 82, 6}, {353, 85, 6}, {363, 87, 6}, {373, 90, 6},
+	{383, 92, 6}, {390, 78, 5}, {393, 79, 5}, {400, 80, 5},
+	{401, 80, 5}, {402, 80, 5}, {403, 81, 5}, {404, 81, 5},
+	{405, 81, 5}, {406, 81, 5}, {407, 81, 5}, {408, 82, 5},
+	{409, 82, 5}, {410, 82, 5}, {411, 82, 5}, {412, 82, 5},
+	{413, 83, 5}, {414, 83, 5}, {415, 83, 5}, {416, 83, 5},
+	{417, 83, 5}, {418, 84, 5}, {419, 84, 5}, {420, 84, 5},
+	{430, 86, 5}, {440, 88, 5}, {450, 90, 5}, {460, 92, 5},
+	{470, 75, 4}, {480, 77, 4}, {490, 78, 4}, {500, 80, 4},
+	{510, 82, 4}, {520, 83, 4}, {530, 85, 4}, {540, 86, 4},
+	{550, 88, 4}, {560, 90, 4}, {570, 91, 4}, {580, 70, 3},
+	{590, 71, 3}, {600, 72, 3}, {610, 73, 3}, {620, 74, 3},
+	{630, 76, 3}, {640, 77, 3}, {650, 78, 3}, {660, 79, 3},
+	{670, 80, 3}, {680, 82, 3}, {690, 83, 3}, {700, 84, 3},
+	{710, 85, 3}, {720, 86, 3}, {730, 88, 3}, {740, 89, 3},
+	{750, 90, 3}, {760, 91, 3}, {770, 92, 3}, {780, 62, 2},
+	{790, 63, 2}, {800, 64, 2}, {880, 70, 2}, {900, 72, 2},
+	{1000, 80, 2},		/* dsi clock frequency in Mhz*/
+};
+
+static int dsi_calc_mnp(u32 dsi_clk, struct dsi_mnp *dsi_mnp)
+{
+	unsigned int i;
+	u8 m;
+	u8 n;
+	u8 p;
+	u32 m_seed;
+
+	if (dsi_clk < 300 || dsi_clk > 1000)
+		return -ECHRNG;
+
+	for (i = 0; i <= ARRAY_SIZE(dsi_clk_tbl); i++) {
+		if (dsi_clk_tbl[i].freq > dsi_clk)
+			break;
+	}
+
+	m = dsi_clk_tbl[i].m;
+	p = dsi_clk_tbl[i].p;
+	m_seed = lfsr_converts[m - 62];
+	n = 1;
+	dsi_mnp->dsi_pll_ctrl = 1 << (DSI_PLL_P1_POST_DIV_SHIFT + p - 2);
+	dsi_mnp->dsi_pll_div = (n - 1) << DSI_PLL_N1_DIV_SHIFT |
+		m_seed << DSI_PLL_M1_DIV_SHIFT;
+
+	return 0;
+}
+
+#else
+
+static int dsi_calc_mnp(u32 dsi_clk, struct dsi_mnp *dsi_mnp)
+{
+	u32 m, n, p;
+	u32 ref_clk;
+	u32 error;
+	u32 tmp_error;
+	u32 target_dsi_clk;
+	u32 calc_dsi_clk;
+	u32 calc_m;
+	u32 calc_p;
+	u32 m_seed;
+
+	if (dsi_clk < 300 || dsi_clk > 1150) {
+		DRM_ERROR("DSI CLK Out of Range\n");
+		return -ECHRNG;
+	}
+
+	ref_clk = 25000;
+	target_dsi_clk = dsi_clk * 1000;
+	error = 0xFFFFFFFF;
+	calc_m = 0;
+	calc_p = 0;
+
+	for (m = 62; m <= 92; m++) {
+		for (p = 2; p <= 6; p++) {
+
+			calc_dsi_clk = (m * ref_clk) / p;
+			if (calc_dsi_clk >= target_dsi_clk) {
+				tmp_error = calc_dsi_clk - target_dsi_clk;
+				if (tmp_error < error) {
+					error = tmp_error;
+					calc_m = m;
+					calc_p = p;
+				}
+			}
+		}
+	}
+
+	m_seed = lfsr_converts[calc_m - 62];
+	n = 1;
+	dsi_mnp->dsi_pll_ctrl = 1 << (DSI_PLL_P1_POST_DIV_SHIFT + calc_p - 2);
+	dsi_mnp->dsi_pll_div = (n - 1) << DSI_PLL_N1_DIV_SHIFT |
+		m_seed << DSI_PLL_M1_DIV_SHIFT;
+
+	return 0;
+}
+
+#endif
+
+/*
+ * XXX: The muxing and gating is hard coded for now. Need to add support for
+ * sharing PLLs with two DSI outputs.
+ */
+static void vlv_configure_dsi_pll(struct intel_encoder *encoder)
+{
+	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
+	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
+	struct drm_display_mode *mode = &intel_crtc->config.requested_mode;
+	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
+	int ret;
+	struct dsi_mnp dsi_mnp;
+	u32 dsi_clk;
+
+	dsi_clk = dsi_rr_formula(mode, intel_dsi->pixel_format,
+				 intel_dsi->video_mode_format,
+				 intel_dsi->lane_count, !intel_dsi->eot_disable);
+
+	ret = dsi_calc_mnp(dsi_clk, &dsi_mnp);
+	if (ret) {
+		DRM_DEBUG_KMS("dsi_calc_mnp failed\n");
+		return;
+	}
+
+	dsi_mnp.dsi_pll_ctrl |= DSI_PLL_CLK_GATE_DSI0_DSIPLL;
+
+	DRM_DEBUG_KMS("dsi pll div %08x, ctrl %08x\n",
+		      dsi_mnp.dsi_pll_div, dsi_mnp.dsi_pll_ctrl);
+
+	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, 0);
+	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_DIVIDER, dsi_mnp.dsi_pll_div);
+	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, dsi_mnp.dsi_pll_ctrl);
+}
+
+void vlv_enable_dsi_pll(struct intel_encoder *encoder)
+{
+	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
+	u32 tmp;
+
+	DRM_DEBUG_KMS("\n");
+
+	mutex_lock(&dev_priv->dpio_lock);
+
+	vlv_configure_dsi_pll(encoder);
+
+	/* wait at least 0.5 us after ungating before enabling VCO */
+	usleep_range(1, 10);
+
+	tmp = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL);
+	tmp |= DSI_PLL_VCO_EN;
+	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, tmp);
+
+	mutex_unlock(&dev_priv->dpio_lock);
+
+	if (wait_for(I915_READ(PIPECONF(PIPE_A)) & PIPECONF_DSI_PLL_LOCKED, 20)) {
+		DRM_ERROR("DSI PLL lock failed\n");
+		return;
+	}
+
+	DRM_DEBUG_KMS("DSI PLL locked\n");
+}
+
+void vlv_disable_dsi_pll(struct intel_encoder *encoder)
+{
+	struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
+	u32 tmp;
+
+	DRM_DEBUG_KMS("\n");
+
+	mutex_lock(&dev_priv->dpio_lock);
+
+	tmp = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL);
+	tmp &= ~DSI_PLL_VCO_EN;
+	tmp |= DSI_PLL_LDO_GATE;
+	vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, tmp);
+
+	mutex_unlock(&dev_priv->dpio_lock);
+}