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/*
* 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/drmP.h>
#include <drm/drm_crtc_helper.h>
#include "armada_crtc.h"
#include "armada_drm.h"
#include "armada_hw.h"
static int armada510_init(struct armada_private *priv, struct device *dev)
{
priv->extclk[0] = devm_clk_get(dev, "ext_ref_clk_1");
if (IS_ERR(priv->extclk[0]) && PTR_ERR(priv->extclk[0]) == -ENOENT)
priv->extclk[0] = ERR_PTR(-EPROBE_DEFER);
return PTR_RET(priv->extclk[0]);
}
static int armada510_crtc_init(struct armada_crtc *dcrtc)
{
/* Lower the watermark so to eliminate jitter at higher bandwidths */
armada_updatel(0x20, (1 << 11) | 0xff, dcrtc->base + LCD_CFG_RDREG4F);
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 armada_private *priv = dcrtc->crtc.dev->dev_private;
struct clk *clk = priv->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;
}
const struct armada_variant armada510_ops = {
.has_spu_adv_reg = true,
.init = armada510_init,
.crtc_init = armada510_crtc_init,
.crtc_compute_clock = armada510_crtc_compute_clock,
};
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