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Revision 2b6c53b1504865728a6dfad3e720918a2f89f3a5 authored by Jon Medhurst (Tixy) on 20 August 2014, 12:41:04 UTC, committed by Tomi Valkeinen on 26 August 2014, 09:50:27 UTC 
video: ARM CLCD: Fix calculation of bits-per-pixel
 
If the device-tree specifies a max-memory-bandwidth property then the
CLCD driver uses that to calculate the bits-per-pixel supported,
however, this calculation is faulty for two reasons.

1. It doesn't ensure that the result is a sane value, i.e. a power of 2
   and <= 32 as the rest of the code assumes.

2. It uses the displayed resolution and calculates the average bandwidth
   across the whole frame. It should instead calculate the peak
   bandwidth based on the pixel clock.

This patch fixes both the above.

Signed-off-by: Jon Medhurst <tixy@linaro.org>
Acked-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
1 parent 754d561
Raw File
sckc.c 
/*
 * drivers/clk/at91/sckc.c
 *
 *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 */

#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/io.h>

#include "sckc.h"

static const struct of_device_id sckc_clk_ids[] __initconst = {
	/* Slow clock */
	{
		.compatible = "atmel,at91sam9x5-clk-slow-osc",
		.data = of_at91sam9x5_clk_slow_osc_setup,
	},
	{
		.compatible = "atmel,at91sam9x5-clk-slow-rc-osc",
		.data = of_at91sam9x5_clk_slow_rc_osc_setup,
	},
	{
		.compatible = "atmel,at91sam9x5-clk-slow",
		.data = of_at91sam9x5_clk_slow_setup,
	},
	{ /*sentinel*/ }
};

static void __init of_at91sam9x5_sckc_setup(struct device_node *np)
{
	struct device_node *childnp;
	void (*clk_setup)(struct device_node *, void __iomem *);
	const struct of_device_id *clk_id;
	void __iomem *regbase = of_iomap(np, 0);

	if (!regbase)
		return;

	for_each_child_of_node(np, childnp) {
		clk_id = of_match_node(sckc_clk_ids, childnp);
		if (!clk_id)
			continue;
		clk_setup = clk_id->data;
		clk_setup(childnp, regbase);
	}
}
CLK_OF_DECLARE(at91sam9x5_clk_sckc, "atmel,at91sam9x5-sckc",
	       of_at91sam9x5_sckc_setup);
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