linux/drivers/gpu/drm/i915/intel_dsi_pll.c
Nicholas Mc Guire 15a43cbf47 drm/i915: relax uncritical udelay_range()
udelay_range(1, 2) is inefficient and as discussions with Jani Nikula
<jani.nikula@linux.intel.com> unnecessary here. This replaces this
tight setting with a relaxed delay of min=20 and max=50 which helps
the hrtimer subsystem optimize timer handling.

Fixes: commit be4fc046be ("drm/i915: add VLV DSI PLL Calculations")
Link: http://lkml.org/lkml/2016/12/15/147
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1481853578-19834-1-git-send-email-hofrat@osadl.org
2016-12-16 11:22:01 +02:00

576 lines
16 KiB
C

/*
* 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"
static const u16 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, 454, 227, 113, 56, 284, 142, /* 81 - 90 */
71, 35, 273, 136, 324, 418, 465, 488, 500, 506 /* 91 - 100 */
};
/* Get DSI clock from pixel clock */
static u32 dsi_clk_from_pclk(u32 pclk, enum mipi_dsi_pixel_format fmt,
int lane_count)
{
u32 dsi_clk_khz;
u32 bpp = mipi_dsi_pixel_format_to_bpp(fmt);
/* DSI data rate = pixel clock * bits per pixel / lane count
pixel clock is converted from KHz to Hz */
dsi_clk_khz = DIV_ROUND_CLOSEST(pclk * bpp, lane_count);
return dsi_clk_khz;
}
static int dsi_calc_mnp(struct drm_i915_private *dev_priv,
struct intel_crtc_state *config,
int target_dsi_clk)
{
unsigned int m_min, m_max, p_min = 2, p_max = 6;
unsigned int m, n, p;
unsigned int calc_m, calc_p;
int delta, ref_clk;
/* target_dsi_clk is expected in kHz */
if (target_dsi_clk < 300000 || target_dsi_clk > 1150000) {
DRM_ERROR("DSI CLK Out of Range\n");
return -ECHRNG;
}
if (IS_CHERRYVIEW(dev_priv)) {
ref_clk = 100000;
n = 4;
m_min = 70;
m_max = 96;
} else {
ref_clk = 25000;
n = 1;
m_min = 62;
m_max = 92;
}
calc_p = p_min;
calc_m = m_min;
delta = abs(target_dsi_clk - (m_min * ref_clk) / (p_min * n));
for (m = m_min; m <= m_max && delta; m++) {
for (p = p_min; p <= p_max && delta; p++) {
/*
* Find the optimal m and p divisors with minimal delta
* +/- the required clock
*/
int calc_dsi_clk = (m * ref_clk) / (p * n);
int d = abs(target_dsi_clk - calc_dsi_clk);
if (d < delta) {
delta = d;
calc_m = m;
calc_p = p;
}
}
}
/* register has log2(N1), this works fine for powers of two */
config->dsi_pll.ctrl = 1 << (DSI_PLL_P1_POST_DIV_SHIFT + calc_p - 2);
config->dsi_pll.div =
(ffs(n) - 1) << DSI_PLL_N1_DIV_SHIFT |
(u32)lfsr_converts[calc_m - 62] << DSI_PLL_M1_DIV_SHIFT;
return 0;
}
/*
* XXX: The muxing and gating is hard coded for now. Need to add support for
* sharing PLLs with two DSI outputs.
*/
static int vlv_compute_dsi_pll(struct intel_encoder *encoder,
struct intel_crtc_state *config)
{
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
int ret;
u32 dsi_clk;
dsi_clk = dsi_clk_from_pclk(intel_dsi->pclk, intel_dsi->pixel_format,
intel_dsi->lane_count);
ret = dsi_calc_mnp(dev_priv, config, dsi_clk);
if (ret) {
DRM_DEBUG_KMS("dsi_calc_mnp failed\n");
return ret;
}
if (intel_dsi->ports & (1 << PORT_A))
config->dsi_pll.ctrl |= DSI_PLL_CLK_GATE_DSI0_DSIPLL;
if (intel_dsi->ports & (1 << PORT_C))
config->dsi_pll.ctrl |= DSI_PLL_CLK_GATE_DSI1_DSIPLL;
config->dsi_pll.ctrl |= DSI_PLL_VCO_EN;
DRM_DEBUG_KMS("dsi pll div %08x, ctrl %08x\n",
config->dsi_pll.div, config->dsi_pll.ctrl);
return 0;
}
static void vlv_enable_dsi_pll(struct intel_encoder *encoder,
const struct intel_crtc_state *config)
{
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
DRM_DEBUG_KMS("\n");
mutex_lock(&dev_priv->sb_lock);
vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, 0);
vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_DIVIDER, config->dsi_pll.div);
vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL,
config->dsi_pll.ctrl & ~DSI_PLL_VCO_EN);
/* wait at least 0.5 us after ungating before enabling VCO,
* allow hrtimer subsystem optimization by relaxing timing
*/
usleep_range(10, 50);
vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, config->dsi_pll.ctrl);
if (wait_for(vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL) &
DSI_PLL_LOCK, 20)) {
mutex_unlock(&dev_priv->sb_lock);
DRM_ERROR("DSI PLL lock failed\n");
return;
}
mutex_unlock(&dev_priv->sb_lock);
DRM_DEBUG_KMS("DSI PLL locked\n");
}
static void vlv_disable_dsi_pll(struct intel_encoder *encoder)
{
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
u32 tmp;
DRM_DEBUG_KMS("\n");
mutex_lock(&dev_priv->sb_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->sb_lock);
}
static bool bxt_dsi_pll_is_enabled(struct drm_i915_private *dev_priv)
{
bool enabled;
u32 val;
u32 mask;
mask = BXT_DSI_PLL_DO_ENABLE | BXT_DSI_PLL_LOCKED;
val = I915_READ(BXT_DSI_PLL_ENABLE);
enabled = (val & mask) == mask;
if (!enabled)
return false;
/*
* Both dividers must be programmed with valid values even if only one
* of the PLL is used, see BSpec/Broxton Clocks. Check this here for
* paranoia, since BIOS is known to misconfigure PLLs in this way at
* times, and since accessing DSI registers with invalid dividers
* causes a system hang.
*/
val = I915_READ(BXT_DSI_PLL_CTL);
if (!(val & BXT_DSIA_16X_MASK) || !(val & BXT_DSIC_16X_MASK)) {
DRM_DEBUG_DRIVER("PLL is enabled with invalid divider settings (%08x)\n",
val);
enabled = false;
}
return enabled;
}
static void bxt_disable_dsi_pll(struct intel_encoder *encoder)
{
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
u32 val;
DRM_DEBUG_KMS("\n");
val = I915_READ(BXT_DSI_PLL_ENABLE);
val &= ~BXT_DSI_PLL_DO_ENABLE;
I915_WRITE(BXT_DSI_PLL_ENABLE, val);
/*
* PLL lock should deassert within 200us.
* Wait up to 1ms before timing out.
*/
if (intel_wait_for_register(dev_priv,
BXT_DSI_PLL_ENABLE,
BXT_DSI_PLL_LOCKED,
0,
1))
DRM_ERROR("Timeout waiting for PLL lock deassertion\n");
}
static void assert_bpp_mismatch(enum mipi_dsi_pixel_format fmt, int pipe_bpp)
{
int bpp = mipi_dsi_pixel_format_to_bpp(fmt);
WARN(bpp != pipe_bpp,
"bpp match assertion failure (expected %d, current %d)\n",
bpp, pipe_bpp);
}
static u32 vlv_dsi_get_pclk(struct intel_encoder *encoder, int pipe_bpp,
struct intel_crtc_state *config)
{
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
u32 dsi_clock, pclk;
u32 pll_ctl, pll_div;
u32 m = 0, p = 0, n;
int refclk = IS_CHERRYVIEW(dev_priv) ? 100000 : 25000;
int i;
DRM_DEBUG_KMS("\n");
mutex_lock(&dev_priv->sb_lock);
pll_ctl = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_CONTROL);
pll_div = vlv_cck_read(dev_priv, CCK_REG_DSI_PLL_DIVIDER);
mutex_unlock(&dev_priv->sb_lock);
config->dsi_pll.ctrl = pll_ctl & ~DSI_PLL_LOCK;
config->dsi_pll.div = pll_div;
/* mask out other bits and extract the P1 divisor */
pll_ctl &= DSI_PLL_P1_POST_DIV_MASK;
pll_ctl = pll_ctl >> (DSI_PLL_P1_POST_DIV_SHIFT - 2);
/* N1 divisor */
n = (pll_div & DSI_PLL_N1_DIV_MASK) >> DSI_PLL_N1_DIV_SHIFT;
n = 1 << n; /* register has log2(N1) */
/* mask out the other bits and extract the M1 divisor */
pll_div &= DSI_PLL_M1_DIV_MASK;
pll_div = pll_div >> DSI_PLL_M1_DIV_SHIFT;
while (pll_ctl) {
pll_ctl = pll_ctl >> 1;
p++;
}
p--;
if (!p) {
DRM_ERROR("wrong P1 divisor\n");
return 0;
}
for (i = 0; i < ARRAY_SIZE(lfsr_converts); i++) {
if (lfsr_converts[i] == pll_div)
break;
}
if (i == ARRAY_SIZE(lfsr_converts)) {
DRM_ERROR("wrong m_seed programmed\n");
return 0;
}
m = i + 62;
dsi_clock = (m * refclk) / (p * n);
/* pixel_format and pipe_bpp should agree */
assert_bpp_mismatch(intel_dsi->pixel_format, pipe_bpp);
pclk = DIV_ROUND_CLOSEST(dsi_clock * intel_dsi->lane_count, pipe_bpp);
return pclk;
}
static u32 bxt_dsi_get_pclk(struct intel_encoder *encoder, int pipe_bpp,
struct intel_crtc_state *config)
{
u32 pclk;
u32 dsi_clk;
u32 dsi_ratio;
struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
/* Divide by zero */
if (!pipe_bpp) {
DRM_ERROR("Invalid BPP(0)\n");
return 0;
}
config->dsi_pll.ctrl = I915_READ(BXT_DSI_PLL_CTL);
dsi_ratio = config->dsi_pll.ctrl & BXT_DSI_PLL_RATIO_MASK;
dsi_clk = (dsi_ratio * BXT_REF_CLOCK_KHZ) / 2;
/* pixel_format and pipe_bpp should agree */
assert_bpp_mismatch(intel_dsi->pixel_format, pipe_bpp);
pclk = DIV_ROUND_CLOSEST(dsi_clk * intel_dsi->lane_count, pipe_bpp);
DRM_DEBUG_DRIVER("Calculated pclk=%u\n", pclk);
return pclk;
}
u32 intel_dsi_get_pclk(struct intel_encoder *encoder, int pipe_bpp,
struct intel_crtc_state *config)
{
if (IS_GEN9_LP(to_i915(encoder->base.dev)))
return bxt_dsi_get_pclk(encoder, pipe_bpp, config);
else
return vlv_dsi_get_pclk(encoder, pipe_bpp, config);
}
static void vlv_dsi_reset_clocks(struct intel_encoder *encoder, enum port port)
{
u32 temp;
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
temp = I915_READ(MIPI_CTRL(port));
temp &= ~ESCAPE_CLOCK_DIVIDER_MASK;
I915_WRITE(MIPI_CTRL(port), temp |
intel_dsi->escape_clk_div <<
ESCAPE_CLOCK_DIVIDER_SHIFT);
}
/* Program BXT Mipi clocks and dividers */
static void bxt_dsi_program_clocks(struct drm_device *dev, enum port port,
const struct intel_crtc_state *config)
{
struct drm_i915_private *dev_priv = to_i915(dev);
u32 tmp;
u32 dsi_rate = 0;
u32 pll_ratio = 0;
u32 rx_div;
u32 tx_div;
u32 rx_div_upper;
u32 rx_div_lower;
u32 mipi_8by3_divider;
/* Clear old configurations */
tmp = I915_READ(BXT_MIPI_CLOCK_CTL);
tmp &= ~(BXT_MIPI_TX_ESCLK_FIXDIV_MASK(port));
tmp &= ~(BXT_MIPI_RX_ESCLK_UPPER_FIXDIV_MASK(port));
tmp &= ~(BXT_MIPI_8X_BY3_DIVIDER_MASK(port));
tmp &= ~(BXT_MIPI_RX_ESCLK_LOWER_FIXDIV_MASK(port));
/* Get the current DSI rate(actual) */
pll_ratio = config->dsi_pll.ctrl & BXT_DSI_PLL_RATIO_MASK;
dsi_rate = (BXT_REF_CLOCK_KHZ * pll_ratio) / 2;
/*
* tx clock should be <= 20MHz and the div value must be
* subtracted by 1 as per bspec
*/
tx_div = DIV_ROUND_UP(dsi_rate, 20000) - 1;
/*
* rx clock should be <= 150MHz and the div value must be
* subtracted by 1 as per bspec
*/
rx_div = DIV_ROUND_UP(dsi_rate, 150000) - 1;
/*
* rx divider value needs to be updated in the
* two differnt bit fields in the register hence splitting the
* rx divider value accordingly
*/
rx_div_lower = rx_div & RX_DIVIDER_BIT_1_2;
rx_div_upper = (rx_div & RX_DIVIDER_BIT_3_4) >> 2;
/* As per bpsec program the 8/3X clock divider to the below value */
if (dev_priv->vbt.dsi.config->is_cmd_mode)
mipi_8by3_divider = 0x2;
else
mipi_8by3_divider = 0x3;
tmp |= BXT_MIPI_8X_BY3_DIVIDER(port, mipi_8by3_divider);
tmp |= BXT_MIPI_TX_ESCLK_DIVIDER(port, tx_div);
tmp |= BXT_MIPI_RX_ESCLK_LOWER_DIVIDER(port, rx_div_lower);
tmp |= BXT_MIPI_RX_ESCLK_UPPER_DIVIDER(port, rx_div_upper);
I915_WRITE(BXT_MIPI_CLOCK_CTL, tmp);
}
static int bxt_compute_dsi_pll(struct intel_encoder *encoder,
struct intel_crtc_state *config)
{
struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
u8 dsi_ratio;
u32 dsi_clk;
dsi_clk = dsi_clk_from_pclk(intel_dsi->pclk, intel_dsi->pixel_format,
intel_dsi->lane_count);
/*
* From clock diagram, to get PLL ratio divider, divide double of DSI
* link rate (i.e., 2*8x=16x frequency value) by ref clock. Make sure to
* round 'up' the result
*/
dsi_ratio = DIV_ROUND_UP(dsi_clk * 2, BXT_REF_CLOCK_KHZ);
if (dsi_ratio < BXT_DSI_PLL_RATIO_MIN ||
dsi_ratio > BXT_DSI_PLL_RATIO_MAX) {
DRM_ERROR("Cant get a suitable ratio from DSI PLL ratios\n");
return -ECHRNG;
}
/*
* Program DSI ratio and Select MIPIC and MIPIA PLL output as 8x
* Spec says both have to be programmed, even if one is not getting
* used. Configure MIPI_CLOCK_CTL dividers in modeset
*/
config->dsi_pll.ctrl = dsi_ratio | BXT_DSIA_16X_BY2 | BXT_DSIC_16X_BY2;
/* As per recommendation from hardware team,
* Prog PVD ratio =1 if dsi ratio <= 50
*/
if (dsi_ratio <= 50)
config->dsi_pll.ctrl |= BXT_DSI_PLL_PVD_RATIO_1;
return 0;
}
static void bxt_enable_dsi_pll(struct intel_encoder *encoder,
const struct intel_crtc_state *config)
{
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
enum port port;
u32 val;
DRM_DEBUG_KMS("\n");
/* Configure PLL vales */
I915_WRITE(BXT_DSI_PLL_CTL, config->dsi_pll.ctrl);
POSTING_READ(BXT_DSI_PLL_CTL);
/* Program TX, RX, Dphy clocks */
for_each_dsi_port(port, intel_dsi->ports)
bxt_dsi_program_clocks(encoder->base.dev, port, config);
/* Enable DSI PLL */
val = I915_READ(BXT_DSI_PLL_ENABLE);
val |= BXT_DSI_PLL_DO_ENABLE;
I915_WRITE(BXT_DSI_PLL_ENABLE, val);
/* Timeout and fail if PLL not locked */
if (intel_wait_for_register(dev_priv,
BXT_DSI_PLL_ENABLE,
BXT_DSI_PLL_LOCKED,
BXT_DSI_PLL_LOCKED,
1)) {
DRM_ERROR("Timed out waiting for DSI PLL to lock\n");
return;
}
DRM_DEBUG_KMS("DSI PLL locked\n");
}
bool intel_dsi_pll_is_enabled(struct drm_i915_private *dev_priv)
{
if (IS_GEN9_LP(dev_priv))
return bxt_dsi_pll_is_enabled(dev_priv);
MISSING_CASE(INTEL_DEVID(dev_priv));
return false;
}
int intel_compute_dsi_pll(struct intel_encoder *encoder,
struct intel_crtc_state *config)
{
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
return vlv_compute_dsi_pll(encoder, config);
else if (IS_GEN9_LP(dev_priv))
return bxt_compute_dsi_pll(encoder, config);
return -ENODEV;
}
void intel_enable_dsi_pll(struct intel_encoder *encoder,
const struct intel_crtc_state *config)
{
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
vlv_enable_dsi_pll(encoder, config);
else if (IS_GEN9_LP(dev_priv))
bxt_enable_dsi_pll(encoder, config);
}
void intel_disable_dsi_pll(struct intel_encoder *encoder)
{
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
vlv_disable_dsi_pll(encoder);
else if (IS_GEN9_LP(dev_priv))
bxt_disable_dsi_pll(encoder);
}
static void bxt_dsi_reset_clocks(struct intel_encoder *encoder, enum port port)
{
u32 tmp;
struct drm_device *dev = encoder->base.dev;
struct drm_i915_private *dev_priv = to_i915(dev);
/* Clear old configurations */
tmp = I915_READ(BXT_MIPI_CLOCK_CTL);
tmp &= ~(BXT_MIPI_TX_ESCLK_FIXDIV_MASK(port));
tmp &= ~(BXT_MIPI_RX_ESCLK_UPPER_FIXDIV_MASK(port));
tmp &= ~(BXT_MIPI_8X_BY3_DIVIDER_MASK(port));
tmp &= ~(BXT_MIPI_RX_ESCLK_LOWER_FIXDIV_MASK(port));
I915_WRITE(BXT_MIPI_CLOCK_CTL, tmp);
I915_WRITE(MIPI_EOT_DISABLE(port), CLOCKSTOP);
}
void intel_dsi_reset_clocks(struct intel_encoder *encoder, enum port port)
{
struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
if (IS_GEN9_LP(dev_priv))
bxt_dsi_reset_clocks(encoder, port);
else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
vlv_dsi_reset_clocks(encoder, port);
}