linux_dsm_epyc7002/drivers/gpu/drm/armada/armada_510.c
Russell King a0fbb35ecd drm/armada: push responsibility for clock management to backend
Push responsibility for managing the clock during DPMS down into the
variant backend, rather than the CRTC layer having knowledge of its
state.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
2018-07-30 11:52:34 +01:00

106 lines
2.5 KiB
C

/*
* Copyright (C) 2012 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Armada 510 (aka Dove) variant support
*/
#include <linux/clk.h>
#include <linux/io.h>
#include <drm/drm_crtc_helper.h>
#include "armada_crtc.h"
#include "armada_drm.h"
#include "armada_hw.h"
static int armada510_crtc_init(struct armada_crtc *dcrtc, struct device *dev)
{
struct clk *clk;
clk = devm_clk_get(dev, "ext_ref_clk1");
if (IS_ERR(clk))
return PTR_ERR(clk) == -ENOENT ? -EPROBE_DEFER : PTR_ERR(clk);
dcrtc->extclk[0] = clk;
/* Lower the watermark so to eliminate jitter at higher bandwidths */
armada_updatel(0x20, (1 << 11) | 0xff, dcrtc->base + LCD_CFG_RDREG4F);
/* Initialise SPU register */
writel_relaxed(ADV_HWC32ENABLE | ADV_HWC32ARGB | ADV_HWC32BLEND,
dcrtc->base + LCD_SPU_ADV_REG);
return 0;
}
/*
* Armada510 specific SCLK register selection.
* This gets called with sclk = NULL to test whether the mode is
* supportable, and again with sclk != NULL to set the clocks up for
* that. The former can return an error, but the latter is expected
* not to.
*
* We currently are pretty rudimentary here, always selecting
* EXT_REF_CLK_1 for LCD0 and erroring LCD1. This needs improvement!
*/
static int armada510_crtc_compute_clock(struct armada_crtc *dcrtc,
const struct drm_display_mode *mode, uint32_t *sclk)
{
struct clk *clk = dcrtc->extclk[0];
int ret;
if (dcrtc->num == 1)
return -EINVAL;
if (IS_ERR(clk))
return PTR_ERR(clk);
if (dcrtc->clk != clk) {
ret = clk_prepare_enable(clk);
if (ret)
return ret;
dcrtc->clk = clk;
}
if (sclk) {
uint32_t rate, ref, div;
rate = mode->clock * 1000;
ref = clk_round_rate(clk, rate);
div = DIV_ROUND_UP(ref, rate);
if (div < 1)
div = 1;
clk_set_rate(clk, ref);
*sclk = div | SCLK_510_EXTCLK1;
}
return 0;
}
static void armada510_crtc_disable(struct armada_crtc *dcrtc)
{
if (!IS_ERR(dcrtc->clk)) {
clk_disable_unprepare(dcrtc->clk);
dcrtc->clk = ERR_PTR(-EINVAL);
}
}
static void armada510_crtc_enable(struct armada_crtc *dcrtc,
const struct drm_display_mode *mode)
{
if (IS_ERR(dcrtc->clk)) {
dcrtc->clk = dcrtc->extclk[0];
WARN_ON(clk_prepare_enable(dcrtc->clk));
}
}
const struct armada_variant armada510_ops = {
.has_spu_adv_reg = true,
.init = armada510_crtc_init,
.compute_clock = armada510_crtc_compute_clock,
.disable = armada510_crtc_disable,
.enable = armada510_crtc_enable,
};