// SPDX-License-Identifier: GPL-2.0-only
/*
* (C) COPYRIGHT 2012-2013 ARM Limited. All rights reserved.
*
* Parts of this file were based on sources as follows:
*
* Copyright (c) 2006-2008 Intel Corporation
* Copyright (c) 2007 Dave Airlie <[email protected]>
* Copyright (C) 2011 Texas Instruments
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dma-buf.h>
#include <linux/media-bus-format.h>
#include <linux/of_graph.h>
#include <drm/drm_fb_dma_helper.h>
#include <drm/drm_fourcc.h>
#include <drm/drm_framebuffer.h>
#include <drm/drm_gem_atomic_helper.h>
#include <drm/drm_gem_dma_helper.h>
#include <drm/drm_vblank.h>
#include "pl111_drm.h"
irqreturn_t pl111_irq(int irq, void *data)
{
struct pl111_drm_dev_private *priv = data;
u32 irq_stat;
irqreturn_t status = IRQ_NONE;
irq_stat = readl(priv->regs + CLCD_PL111_MIS);
if (!irq_stat)
return IRQ_NONE;
if (irq_stat & CLCD_IRQ_NEXTBASE_UPDATE) {
drm_crtc_handle_vblank(&priv->pipe.crtc);
status = IRQ_HANDLED;
}
/* Clear the interrupt once done */
writel(irq_stat, priv->regs + CLCD_PL111_ICR);
return status;
}
static enum drm_mode_status
pl111_mode_valid(struct drm_simple_display_pipe *pipe,
const struct drm_display_mode *mode)
{
struct drm_device *drm = pipe->crtc.dev;
struct pl111_drm_dev_private *priv = drm->dev_private;
u32 cpp = DIV_ROUND_UP(priv->variant->fb_depth, 8);
u64 bw;
/*
* We use the pixelclock to also account for interlaced modes, the
* resulting bandwidth is in bytes per second.
*/
bw = mode->clock * 1000ULL; /* In Hz */
bw = bw * mode->hdisplay * mode->vdisplay * cpp;
bw = div_u64(bw, mode->htotal * mode->vtotal);
/*
* If no bandwidth constraints, anything goes, else
* check if we are too fast.
*/
if (priv->memory_bw && (bw > priv->memory_bw)) {
DRM_DEBUG_KMS("%d x %d @ %d Hz, %d cpp, bw %llu too fast\n",
mode->hdisplay, mode->vdisplay,
mode->clock * 1000, cpp, bw);
return MODE_BAD;
}
DRM_DEBUG_KMS("%d x %d @ %d Hz, %d cpp, bw %llu bytes/s OK\n",
mode->hdisplay, mode->vdisplay,
mode->clock * 1000, cpp, bw);
return MODE_OK;
}
static int pl111_display_check(struct drm_simple_display_pipe *pipe,
struct drm_plane_state *pstate,
struct drm_crtc_state *cstate)
{
const struct drm_display_mode *mode = &cstate->mode;
struct drm_framebuffer *old_fb = pipe->plane.state->fb;
struct drm_framebuffer *fb = pstate->fb;
if (mode->hdisplay % 16)
return -EINVAL;
if (fb) {
u32 offset = drm_fb_dma_get_gem_addr(fb, pstate, 0);
/* FB base address must be dword aligned. */
if (offset & 3)
return -EINVAL;
/* There's no pitch register -- the mode's hdisplay
* controls it.
*/
if (fb->pitches[0] != mode->hdisplay * fb->format->cpp[0])
return -EINVAL;
/* We can't change the FB format in a flicker-free
* manner (and only update it during CRTC enable).
*/
if (old_fb && old_fb->format != fb->format)
cstate->mode_changed = true;
}
return 0;
}
static void pl111_display_enable(struct drm_simple_display_pipe *pipe,
struct drm_crtc_state *cstate,
struct drm_plane_state *plane_state)
{
struct drm_crtc *crtc = &pipe->crtc;
struct drm_plane *plane = &pipe->plane;
struct drm_device *drm = crtc->dev;
struct pl111_drm_dev_private *priv = drm->dev_private;
const struct drm_display_mode *mode = &cstate->mode;
struct drm_framebuffer *fb = plane->state->fb;
struct drm_connector *connector = priv->connector;
struct drm_bridge *bridge = priv->bridge;
bool grayscale = false;
u32 cntl;
u32 ppl, hsw, hfp, hbp;
u32 lpp, vsw, vfp, vbp;
u32 cpl, tim2;
int ret;
ret = clk_set_rate(priv->clk, mode->clock * 1000);
if (ret) {
dev_err(drm->dev,
"Failed to set pixel clock rate to %d: %d\n",
mode->clock * 1000, ret);
}
clk_prepare_enable(priv->clk);
ppl = (mode->hdisplay / 16) - 1;
hsw = mode->hsync_end - mode->hsync_start - 1;
hfp = mode->hsync_start - mode->hdisplay - 1;
hbp = mode->htotal - mode->hsync_end - 1;
lpp = mode->vdisplay - 1;
vsw = mode->vsync_end - mode->vsync_start - 1;
vfp = mode->vsync_start - mode->vdisplay;
vbp = mode->vtotal - mode->vsync_end;
cpl = mode->hdisplay - 1;
writel((ppl << 2) |
(hsw << 8) |
(hfp << 16) |
(hbp << 24),
priv->regs + CLCD_TIM0);
writel(lpp |
(vsw << 10) |
(vfp << 16) |
(vbp << 24),
priv->regs + CLCD_TIM1);
spin_lock(&priv->tim2_lock);
tim2 = readl(priv->regs + CLCD_TIM2);
tim2 &= (TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
if (priv->variant->broken_clockdivider)
tim2 |= TIM2_BCD;
if (mode->flags & DRM_MODE_FLAG_NHSYNC)
tim2 |= TIM2_IHS;
if (mode->flags & DRM_MODE_FLAG_NVSYNC)
tim2 |= TIM2_IVS;
if (connector) {
if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
tim2 |= TIM2_IOE;
if (connector->display_info.bus_flags &
DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
tim2 |= TIM2_IPC;
if (connector->display_info.num_bus_formats == 1 &&
connector->display_info.bus_formats[0] ==
MEDIA_BUS_FMT_Y8_1X8)
grayscale = true;
/*
* The AC pin bias frequency is set to max count when using
* grayscale so at least once in a while we will reverse
* polarity and get rid of any DC built up that could
* damage the display.
*/
if (grayscale)
tim2 |= TIM2_ACB_MASK;
}
if (bridge) {
const struct drm_bridge_timings *btimings = bridge->timings;
/*
* Here is when things get really fun. Sometimes the bridge
* timings are such that the signal out from PL11x is not
* stable before the receiving bridge (such as a dumb VGA DAC
* or similar) samples it. If that happens, we compensate by
* the only method we have: output the data on the opposite
* edge of the clock so it is for sure stable when it gets
* sampled.
*
* The PL111 manual does not contain proper timining diagrams
* or data for these details, but we know from experiments
* that the setup time is more than 3000 picoseconds (3 ns).
* If we have a bridge that requires the signal to be stable
* earlier than 3000 ps before the clock pulse, we have to
* output the data on the opposite edge to avoid flicker.
*/
if (btimings && btimings->setup_time_ps >= 3000)
tim2 ^= TIM2_IPC;
}
tim2 |= cpl << 16;
writel(tim2, priv->regs + CLCD_TIM2);
spin_unlock(&priv->tim2_lock);
writel(0, priv->regs + CLCD_TIM3);
/*
* Detect grayscale bus format. We do not support a grayscale mode
* toward userspace, instead we expose an RGB24 buffer and then the
* hardware will activate its grayscaler to convert to the grayscale
* format.
*/
if (grayscale)
cntl = CNTL_LCDEN | CNTL_LCDMONO8;
else
/* Else we assume TFT display */
cntl = CNTL_LCDEN | CNTL_LCDTFT | CNTL_LCDVCOMP(1);
/* On the ST Micro variant, assume all 24 bits are connected */
if (priv->variant->st_bitmux_control)
cntl |= CNTL_ST_CDWID_24;
/*
* Note that the ARM hardware's format reader takes 'r' from
* the low bit, while DRM formats list channels from high bit
* to low bit as you read left to right. The ST Micro version of
* the PL110 (LCDC) however uses the standard DRM format.
*/
switch (fb->format->format) {
case DRM_FORMAT_BGR888:
/* Only supported on the ST Micro variant */
if (priv->variant->st_bitmux_control)
cntl |= CNTL_ST_LCDBPP24_PACKED | CNTL_BGR;
break;
case DRM_FORMAT_RGB888:
/* Only supported on the ST Micro variant */
if (priv->variant->st_bitmux_control)
cntl |= CNTL_ST_LCDBPP24_PACKED;
break;
case DRM_FORMAT_ABGR8888:
case DRM_FORMAT_XBGR8888:
if (priv->variant->st_bitmux_control)
cntl |= CNTL_LCDBPP24 | CNTL_BGR;
else
cntl |= CNTL_LCDBPP24;
break;
case DRM_FORMAT_ARGB8888:
case DRM_FORMAT_XRGB8888:
if (priv->variant->st_bitmux_control)
cntl |= CNTL_LCDBPP24;
else
cntl |= CNTL_LCDBPP24 | CNTL_BGR;
break;
case DRM_FORMAT_BGR565:
if (priv->variant->is_pl110)
cntl |= CNTL_LCDBPP16;
else if (priv->variant->st_bitmux_control)
cntl |= CNTL_LCDBPP16 | CNTL_ST_1XBPP_565 | CNTL_BGR;
else
cntl |= CNTL_LCDBPP16_565;
break;
case DRM_FORMAT_RGB565:
if (priv->variant->is_pl110)
cntl |= CNTL_LCDBPP16 | CNTL_BGR;
else if (priv->variant->st_bitmux_control)
cntl |= CNTL_LCDBPP16 | CNTL_ST_1XBPP_565;
else
cntl |= CNTL_LCDBPP16_565 | CNTL_BGR;
break;
case DRM_FORMAT_ABGR1555:
case DRM_FORMAT_XBGR1555:
cntl |= CNTL_LCDBPP16;
if (priv->variant->st_bitmux_control)
cntl |= CNTL_ST_1XBPP_5551 | CNTL_BGR;
break;
case DRM_FORMAT_ARGB1555:
case DRM_FORMAT_XRGB1555:
cntl |= CNTL_LCDBPP16;
if (priv->variant->st_bitmux_control)
cntl |= CNTL_ST_1XBPP_5551;
else
cntl |= CNTL_BGR;
break;
case DRM_FORMAT_ABGR4444:
case DRM_FORMAT_XBGR4444:
cntl |= CNTL_LCDBPP16_444;
if (priv->variant->st_bitmux_control)
cntl |= CNTL_ST_1XBPP_444 | CNTL_BGR;
break;
case DRM_FORMAT_ARGB4444:
case DRM_FORMAT_XRGB4444:
cntl |= CNTL_LCDBPP16_444;
if (priv->variant->st_bitmux_control)
cntl |= CNTL_ST_1XBPP_444;
else
cntl |= CNTL_BGR;
break;
default:
WARN_ONCE(true, "Unknown FB format 0x%08x\n",
fb->format->format);
break;
}
/* The PL110 in Integrator/Versatile does the BGR routing externally */
if (priv->variant->external_bgr)
cntl &= ~CNTL_BGR;
/* Power sequence: first enable and chill */
writel(cntl, priv->regs + priv->ctrl);
/*
* We expect this delay to stabilize the contrast
* voltage Vee as stipulated by the manual
*/
msleep(20);
if (priv->variant_display_enable)
priv->variant_display_enable(drm, fb->format->format);
/* Power Up */
cntl |= CNTL_LCDPWR;
writel(cntl, priv->regs + priv->ctrl);
if (!priv->variant->broken_vblank)
drm_crtc_vblank_on(crtc);
}
static void pl111_display_disable(struct drm_simple_display_pipe *pipe)
{
struct drm_crtc *crtc = &pipe->crtc;
struct drm_device *drm = crtc->dev;
struct pl111_drm_dev_private *priv = drm->dev_private;
u32 cntl;
if (!priv->variant->broken_vblank)
drm_crtc_vblank_off(crtc);
/* Power Down */
cntl = readl(priv->regs + priv->ctrl);
if (cntl & CNTL_LCDPWR) {
cntl &= ~CNTL_LCDPWR;
writel(cntl, priv->regs + priv->ctrl);
}
/*
* We expect this delay to stabilize the contrast voltage Vee as
* stipulated by the manual
*/
msleep(20);
if (priv->variant_display_disable)
priv->variant_display_disable(drm);
/* Disable */
writel(0, priv->regs + priv->ctrl);
clk_disable_unprepare(priv->clk);
}
static void pl111_display_update(struct drm_simple_display_pipe *pipe,
struct drm_plane_state *old_pstate)
{
struct drm_crtc *crtc = &pipe->crtc;
struct drm_device *drm = crtc->dev;
struct pl111_drm_dev_private *priv = drm->dev_private;
struct drm_pending_vblank_event *event = crtc->state->event;
struct drm_plane *plane = &pipe->plane;
struct drm_plane_state *pstate = plane->state;
struct drm_framebuffer *fb = pstate->fb;
if (fb) {
u32 addr = drm_fb_dma_get_gem_addr(fb, pstate, 0);
writel(addr, priv->regs + CLCD_UBAS);
}
if (event) {
crtc->state->event = NULL;
spin_lock_irq(&crtc->dev->event_lock);
if (crtc->state->active && drm_crtc_vblank_get(crtc) == 0)
drm_crtc_arm_vblank_event(crtc, event);
else
drm_crtc_send_vblank_event(crtc, event);
spin_unlock_irq(&crtc->dev->event_lock);
}
}
static int pl111_display_enable_vblank(struct drm_simple_display_pipe *pipe)
{
struct drm_crtc *crtc = &pipe->crtc;
struct drm_device *drm = crtc->dev;
struct pl111_drm_dev_private *priv = drm->dev_private;
writel(CLCD_IRQ_NEXTBASE_UPDATE, priv->regs + priv->ienb);
return 0;
}
static void pl111_display_disable_vblank(struct drm_simple_display_pipe *pipe)
{
struct drm_crtc *crtc = &pipe->crtc;
struct drm_device *drm = crtc->dev;
struct pl111_drm_dev_private *priv = drm->dev_private;
writel(0, priv->regs + priv->ienb);
}
static struct drm_simple_display_pipe_funcs pl111_display_funcs = {
.mode_valid = pl111_mode_valid,
.check = pl111_display_check,
.enable = pl111_display_enable,
.disable = pl111_display_disable,
.update = pl111_display_update,
};
static int pl111_clk_div_choose_div(struct clk_hw *hw, unsigned long rate,
unsigned long *prate, bool set_parent)
{
int best_div = 1, div;
struct clk_hw *parent = clk_hw_get_parent(hw);
unsigned long best_prate = 0;
unsigned long best_diff = ~0ul;
int max_div = (1 << (TIM2_PCD_LO_BITS + TIM2_PCD_HI_BITS)) - 1;
for (div = 1; div < max_div; div++) {
unsigned long this_prate, div_rate, diff;
if (set_parent)
this_prate = clk_hw_round_rate(parent, rate * div);
else
this_prate = *prate;
div_rate = DIV_ROUND_UP_ULL(this_prate, div);
diff = abs(rate - div_rate);
if (diff < best_diff) {
best_div = div;
best_diff = diff;
best_prate = this_prate;
}
}
*prate = best_prate;
return best_div;
}
static long pl111_clk_div_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
int div = pl111_clk_div_choose_div(hw, rate, prate, true);
return DIV_ROUND_UP_ULL(*prate, div);
}
static unsigned long pl111_clk_div_recalc_rate(struct clk_hw *hw,
unsigned long prate)
{
struct pl111_drm_dev_private *priv =
container_of(hw, struct pl111_drm_dev_private, clk_div);
u32 tim2 = readl(priv->regs + CLCD_TIM2);
int div;
if (tim2 & TIM2_BCD)
return prate;
div = tim2 & TIM2_PCD_LO_MASK;
div |= (tim2 & TIM2_PCD_HI_MASK) >>
(TIM2_PCD_HI_SHIFT - TIM2_PCD_LO_BITS);
div += 2;
return DIV_ROUND_UP_ULL(prate, div);
}
static int pl111_clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long prate)
{
struct pl111_drm_dev_private *priv =
container_of(hw, struct pl111_drm_dev_private, clk_div);
int div = pl111_clk_div_choose_div(hw, rate, &prate, false);
u32 tim2;
spin_lock(&priv->tim2_lock);
tim2 = readl(priv->regs + CLCD_TIM2);
tim2 &= ~(TIM2_BCD | TIM2_PCD_LO_MASK | TIM2_PCD_HI_MASK);
if (div == 1) {
tim2 |= TIM2_BCD;
} else {
div -= 2;
tim2 |= div & TIM2_PCD_LO_MASK;
tim2 |= (div >> TIM2_PCD_LO_BITS) << TIM2_PCD_HI_SHIFT;
}
writel(tim2, priv->regs + CLCD_TIM2);
spin_unlock(&priv->tim2_lock);
return 0;
}
static const struct clk_ops pl111_clk_div_ops = {
.recalc_rate = pl111_clk_div_recalc_rate,
.round_rate = pl111_clk_div_round_rate,
.set_rate = pl111_clk_div_set_rate,
};
static int
pl111_init_clock_divider(struct drm_device *drm)
{
struct pl111_drm_dev_private *priv = drm->dev_private;
struct clk *parent = devm_clk_get(drm->dev, "clcdclk");
struct clk_hw *div = &priv->clk_div;
const char *parent_name;
struct clk_init_data init = {
.name = "pl111_div",
.ops = &pl111_clk_div_ops,
.parent_names = &parent_name,
.num_parents = 1,
.flags = CLK_SET_RATE_PARENT,
};
int ret;
if (IS_ERR(parent)) {
dev_err(drm->dev, "CLCD: unable to get clcdclk.\n");
return PTR_ERR(parent);
}
spin_lock_init(&priv->tim2_lock);
/* If the clock divider is broken, use the parent directly */
if (priv->variant->broken_clockdivider) {
priv->clk = parent;
return 0;
}
parent_name = __clk_get_name(parent);
div->init = &init;
ret = devm_clk_hw_register(drm->dev, div);
priv->clk = div->clk;
return ret;
}
int pl111_display_init(struct drm_device *drm)
{
struct pl111_drm_dev_private *priv = drm->dev_private;
int ret;
ret = pl111_init_clock_divider(drm);
if (ret)
return ret;
if (!priv->variant->broken_vblank) {
pl111_display_funcs.enable_vblank = pl111_display_enable_vblank;
pl111_display_funcs.disable_vblank = pl111_display_disable_vblank;
}
ret = drm_simple_display_pipe_init(drm, &priv->pipe,
&pl111_display_funcs,
priv->variant->formats,
priv->variant->nformats,
NULL,
priv->connector);
if (ret)
return ret;
return 0;
}
Codebase Browser
linux