[deliverable/linux.git] / drivers / mmc / host / sdhci-cns3xxx.c

/*
 * SDHCI support for CNS3xxx SoC
 *
 * Copyright 2008 Cavium Networks
 * Copyright 2010 MontaVista Software, LLC.
 *
 * Authors: Scott Shu
 *	    Anton Vorontsov <avorontsov@mvista.com>
 *
 * 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.
 */

#include <linux/delay.h>
#include <linux/device.h>
#include <linux/mmc/host.h>
#include <linux/module.h>
#include "sdhci-pltfm.h"

static unsigned int sdhci_cns3xxx_get_max_clk(struct sdhci_host *host)
{
	return 150000000;
}

static void sdhci_cns3xxx_set_clock(struct sdhci_host *host, unsigned int clock)
{
	struct device *dev = mmc_dev(host->mmc);
	int div = 1;
	u16 clk;
	unsigned long timeout;

	if (clock == host->clock)
		return;

	sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);

	if (clock == 0)
		goto out;

	while (host->max_clk / div > clock) {
		/*
		 * On CNS3xxx divider grows linearly up to 4, and then
		 * exponentially up to 256.
		 */
		if (div < 4)
			div += 1;
		else if (div < 256)
			div *= 2;
		else
			break;
	}

	dev_dbg(dev, "desired SD clock: %d, actual: %d\n",
		clock, host->max_clk / div);

	/* Divide by 3 is special. */
	if (div != 3)
		div >>= 1;

	clk = div << SDHCI_DIVIDER_SHIFT;
	clk |= SDHCI_CLOCK_INT_EN;
	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);

	timeout = 20;
	while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
			& SDHCI_CLOCK_INT_STABLE)) {
		if (timeout == 0) {
			dev_warn(dev, "clock is unstable");
			break;
		}
		timeout--;
		mdelay(1);
	}

	clk |= SDHCI_CLOCK_CARD_EN;
	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
out:
	host->clock = clock;
}

static const struct sdhci_ops sdhci_cns3xxx_ops = {
	.get_max_clock	= sdhci_cns3xxx_get_max_clk,
	.set_clock	= sdhci_cns3xxx_set_clock,
};

static const struct sdhci_pltfm_data sdhci_cns3xxx_pdata = {
	.ops = &sdhci_cns3xxx_ops,
	.quirks = SDHCI_QUIRK_BROKEN_DMA |
		  SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
		  SDHCI_QUIRK_INVERTED_WRITE_PROTECT |
		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
		  SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
		  SDHCI_QUIRK_NONSTANDARD_CLOCK,
};

static int sdhci_cns3xxx_probe(struct platform_device *pdev)
{
	return sdhci_pltfm_register(pdev, &sdhci_cns3xxx_pdata, 0);
}

static int sdhci_cns3xxx_remove(struct platform_device *pdev)
{
	return sdhci_pltfm_unregister(pdev);
}

static struct platform_driver sdhci_cns3xxx_driver = {
	.driver		= {
		.name	= "sdhci-cns3xxx",
		.owner	= THIS_MODULE,
		.pm	= SDHCI_PLTFM_PMOPS,
	},
	.probe		= sdhci_cns3xxx_probe,
	.remove		= sdhci_cns3xxx_remove,
};

module_platform_driver(sdhci_cns3xxx_driver);

MODULE_DESCRIPTION("SDHCI driver for CNS3xxx");
MODULE_AUTHOR("Scott Shu, "
	      "Anton Vorontsov <avorontsov@mvista.com>");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
20b1597b AV	1	/*
	2	* SDHCI support for CNS3xxx SoC
	3	*
	4	* Copyright 2008 Cavium Networks
	5	* Copyright 2010 MontaVista Software, LLC.
	6	*
	7	* Authors: Scott Shu
	8	* Anton Vorontsov <avorontsov@mvista.com>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*/
	14
	15	#include <linux/delay.h>
	16	#include <linux/device.h>
	17	#include <linux/mmc/host.h>
7833c66b	18	#include <linux/module.h>
20b1597b AV	19	#include "sdhci-pltfm.h"
	20
	21	static unsigned int sdhci_cns3xxx_get_max_clk(struct sdhci_host *host)
	22	{
	23	return 150000000;
	24	}
	25
	26	static void sdhci_cns3xxx_set_clock(struct sdhci_host *host, unsigned int clock)
	27	{
	28	struct device *dev = mmc_dev(host->mmc);
	29	int div = 1;
	30	u16 clk;
	31	unsigned long timeout;
	32
	33	if (clock == host->clock)
	34	return;
	35
	36	sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
	37
	38	if (clock == 0)
	39	goto out;
	40
	41	while (host->max_clk / div > clock) {
	42	/*
	43	* On CNS3xxx divider grows linearly up to 4, and then
	44	* exponentially up to 256.
	45	*/
	46	if (div < 4)
	47	div += 1;
	48	else if (div < 256)
	49	div *= 2;
	50	else
	51	break;
	52	}
	53
	54	dev_dbg(dev, "desired SD clock: %d, actual: %d\n",
	55	clock, host->max_clk / div);
	56
	57	/* Divide by 3 is special. */
	58	if (div != 3)
	59	div >>= 1;
	60
	61	clk = div << SDHCI_DIVIDER_SHIFT;
	62	clk \|= SDHCI_CLOCK_INT_EN;
	63	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
	64
	65	timeout = 20;
	66	while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
	67	& SDHCI_CLOCK_INT_STABLE)) {
	68	if (timeout == 0) {
	69	dev_warn(dev, "clock is unstable");
	70	break;
	71	}
	72	timeout--;
	73	mdelay(1);
	74	}
	75
	76	clk \|= SDHCI_CLOCK_CARD_EN;
	77	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
	78	out:
	79	host->clock = clock;
	80	}
	81
c915568d	82	static const struct sdhci_ops sdhci_cns3xxx_ops = {
20b1597b AV	83	.get_max_clock = sdhci_cns3xxx_get_max_clk,
	84	.set_clock = sdhci_cns3xxx_set_clock,
	85	};
	86
1db5eebf	87	static const struct sdhci_pltfm_data sdhci_cns3xxx_pdata = {
20b1597b AV	88	.ops = &sdhci_cns3xxx_ops,
	89	.quirks = SDHCI_QUIRK_BROKEN_DMA \|
	90	SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK \|
	91	SDHCI_QUIRK_INVERTED_WRITE_PROTECT \|
	92	SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN \|
	93	SDHCI_QUIRK_BROKEN_TIMEOUT_VAL \|
	94	SDHCI_QUIRK_NONSTANDARD_CLOCK,
	95	};
85d6509d	96
c3be1efd	97	static int sdhci_cns3xxx_probe(struct platform_device *pdev)
85d6509d	98	{
0e748234	99	return sdhci_pltfm_register(pdev, &sdhci_cns3xxx_pdata, 0);
85d6509d SG	100	}
85d6509d SG	101
6e0ee714	102	static int sdhci_cns3xxx_remove(struct platform_device *pdev)
85d6509d SG	103	{
	104	return sdhci_pltfm_unregister(pdev);
	105	}
	106
	107	static struct platform_driver sdhci_cns3xxx_driver = {
	108	.driver = {
	109	.name = "sdhci-cns3xxx",
	110	.owner = THIS_MODULE,
29495aa0	111	.pm = SDHCI_PLTFM_PMOPS,
85d6509d SG	112	},
85d6509d SG	113	.probe = sdhci_cns3xxx_probe,
0433c143	114	.remove = sdhci_cns3xxx_remove,
85d6509d SG	115	};
85d6509d SG	116
d1f81a64	117	module_platform_driver(sdhci_cns3xxx_driver);
85d6509d SG	118
	119	MODULE_DESCRIPTION("SDHCI driver for CNS3xxx");
	120	MODULE_AUTHOR("Scott Shu, "
	121	"Anton Vorontsov <avorontsov@mvista.com>");
	122	MODULE_LICENSE("GPL v2");