2 * Copyright (C) 2012 Russell King
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 * Armada 510 (aka Dove) variant support
10 #include <linux/clk.h>
13 #include <drm/drm_crtc_helper.h>
14 #include "armada_crtc.h"
15 #include "armada_drm.h"
16 #include "armada_hw.h"
18 static int armada510_crtc_init(struct armada_crtc *dcrtc, struct device *dev)
22 clk = devm_clk_get(dev, "ext_ref_clk1");
24 return PTR_ERR(clk) == -ENOENT ? -EPROBE_DEFER : PTR_ERR(clk);
26 dcrtc->extclk[0] = clk;
28 /* Lower the watermark so to eliminate jitter at higher bandwidths */
29 armada_updatel(0x20, (1 << 11) | 0xff, dcrtc->base + LCD_CFG_RDREG4F);
35 * Armada510 specific SCLK register selection.
36 * This gets called with sclk = NULL to test whether the mode is
37 * supportable, and again with sclk != NULL to set the clocks up for
38 * that. The former can return an error, but the latter is expected
41 * We currently are pretty rudimentary here, always selecting
42 * EXT_REF_CLK_1 for LCD0 and erroring LCD1. This needs improvement!
44 static int armada510_crtc_compute_clock(struct armada_crtc *dcrtc,
45 const struct drm_display_mode *mode, uint32_t *sclk)
47 struct clk *clk = dcrtc->extclk[0];
56 if (dcrtc->clk != clk) {
57 ret = clk_prepare_enable(clk);
64 uint32_t rate, ref, div;
66 rate = mode->clock * 1000;
67 ref = clk_round_rate(clk, rate);
68 div = DIV_ROUND_UP(ref, rate);
72 clk_set_rate(clk, ref);
73 *sclk = div | SCLK_510_EXTCLK1;
79 const struct armada_variant armada510_ops = {
80 .has_spu_adv_reg = true,
81 .spu_adv_reg = ADV_HWC32ENABLE | ADV_HWC32ARGB | ADV_HWC32BLEND,
82 .init = armada510_crtc_init,
83 .compute_clock = armada510_crtc_compute_clock,