/*
* Copyright (C) 2013 Broadcom Corporation
*
* 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 version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/highmem.h>
#include <linux/platform_device.h>
#include <linux/mmc/host.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/clk.h>
#include <linux/regulator/consumer.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/mmc/slot-gpio.h>
#include "sdhci-pltfm.h"
#include "sdhci.h"
#define SDHCI_SOFT_RESET 0x01000000
#define KONA_SDHOST_CORECTRL 0x8000
#define KONA_SDHOST_CD_PINCTRL 0x00000008
#define KONA_SDHOST_STOP_HCLK 0x00000004
#define KONA_SDHOST_RESET 0x00000002
#define KONA_SDHOST_EN 0x00000001
#define KONA_SDHOST_CORESTAT 0x8004
#define KONA_SDHOST_WP 0x00000002
#define KONA_SDHOST_CD_SW 0x00000001
#define KONA_SDHOST_COREIMR 0x8008
#define KONA_SDHOST_IP 0x00000001
#define KONA_SDHOST_COREISR 0x800C
#define KONA_SDHOST_COREIMSR 0x8010
#define KONA_SDHOST_COREDBG1 0x8014
#define KONA_SDHOST_COREGPO_MASK 0x8018
#define SD_DETECT_GPIO_DEBOUNCE_128MS 128
#define KONA_MMC_AUTOSUSPEND_DELAY (50)
struct sdhci_bcm_kona_dev {
struct mutex write_lock; /* protect back to back writes */
};
static int sdhci_bcm_kona_sd_reset(struct sdhci_host *host)
{
unsigned int val;
unsigned long timeout;
/* This timeout should be sufficent for core to reset */
timeout = jiffies + msecs_to_jiffies(100);
/* reset the host using the top level reset */
val = sdhci_readl(host, KONA_SDHOST_CORECTRL);
val |= KONA_SDHOST_RESET;
sdhci_writel(host, val, KONA_SDHOST_CORECTRL);
while (!(sdhci_readl(host, KONA_SDHOST_CORECTRL) & KONA_SDHOST_RESET)) {
if (time_is_before_jiffies(timeout)) {
pr_err("Error: sd host is stuck in reset!!!\n");
return -EFAULT;
}
}
/* bring the host out of reset */
val = sdhci_readl(host, KONA_SDHOST_CORECTRL);
val &= ~KONA_SDHOST_RESET;
/*
* Back-to-Back register write needs a delay of 1ms at bootup (min 10uS)
* Back-to-Back writes to same register needs delay when SD bus clock
* is very low w.r.t AHB clock, mainly during boot-time and during card
* insert-removal.
*/
usleep_range(1000, 5000);
sdhci_writel(host, val, KONA_SDHOST_CORECTRL);
return 0;
}
static void sdhci_bcm_kona_sd_init(struct sdhci_host *host)
{
unsigned int val;
/* enable the interrupt from the IP core */
val = sdhci_readl(host, KONA_SDHOST_COREIMR);
val |= KONA_SDHOST_IP;
sdhci_writel(host, val, KONA_SDHOST_COREIMR);
/* Enable the AHB clock gating module to the host */
val = sdhci_readl(host, KONA_SDHOST_CORECTRL);
val |= KONA_SDHOST_EN;
/*
* Back-to-Back register write needs a delay of 1ms at bootup (min 10uS)
* Back-to-Back writes to same register needs delay when SD bus clock
* is very low w.r.t AHB clock, mainly during boot-time and during card
* insert-removal.
*/
usleep_range(1000, 5000);
sdhci_writel(host, val, KONA_SDHOST_CORECTRL);
}
/*
* Software emulation of the SD card insertion/removal. Set insert=1 for insert
* and insert=0 for removal. The card detection is done by GPIO. For Broadcom
* IP to function properly the bit 0 of CORESTAT register needs to be set/reset
* to generate the CD IRQ handled in sdhci.c which schedules card_tasklet.
*/
static int sdhci_bcm_kona_sd_card_emulate(struct sdhci_host *host, int insert)
{
struct sdhci_pltfm_host *pltfm_priv = sdhci_priv(host);
struct sdhci_bcm_kona_dev *kona_dev = sdhci_pltfm_priv(pltfm_priv);
u32 val;
/*
* Back-to-Back register write needs a delay of min 10uS.
* Back-to-Back writes to same register needs delay when SD bus clock
* is very low w.r.t AHB clock, mainly during boot-time and during card
* insert-removal.
* We keep 20uS
*/
mutex_lock(&kona_dev->write_lock);
udelay(20);
val = sdhci_readl(host, KONA_SDHOST_CORESTAT);
if (insert) {
int ret;
ret = mmc_gpio_get_ro(host->mmc);
if (ret >= 0)
val = (val & ~KONA_SDHOST_WP) |
((ret) ? KONA_SDHOST_WP : 0);
val |= KONA_SDHOST_CD_SW;
sdhci_writel(host, val, KONA_SDHOST_CORESTAT);
} else {
val &= ~KONA_SDHOST_CD_SW;
sdhci_writel(host, val, KONA_SDHOST_CORESTAT);
}
mutex_unlock(&kona_dev->write_lock);
return 0;
}
/*
* SD card interrupt event callback
*/
static void sdhci_bcm_kona_card_event(struct sdhci_host *host)
{
if (mmc_gpio_get_cd(host->mmc) > 0) {
dev_dbg(mmc_dev(host->mmc),
"card inserted\n");
sdhci_bcm_kona_sd_card_emulate(host, 1);
} else {
dev_dbg(mmc_dev(host->mmc),
"card removed\n");
sdhci_bcm_kona_sd_card_emulate(host, 0);
}
}
static void sdhci_bcm_kona_init_74_clocks(struct sdhci_host *host,
u8 power_mode)
{
/*
* JEDEC and SD spec specify supplying 74 continuous clocks to
* device after power up. With minimum bus (100KHz) that
* that translates to 740us
*/
if (power_mode != MMC_POWER_OFF)
udelay(740);
}
static struct sdhci_ops sdhci_bcm_kona_ops = {
.set_clock = sdhci_set_clock,
.get_max_clock = sdhci_pltfm_clk_get_max_clock,
.get_timeout_clock = sdhci_pltfm_clk_get_max_clock,
.platform_send_init_74_clocks = sdhci_bcm_kona_init_74_clocks,
.set_bus_width = sdhci_set_bus_width,
.reset = sdhci_reset,
.set_uhs_signaling = sdhci_set_uhs_signaling,
.card_event = sdhci_bcm_kona_card_event,
};
static struct sdhci_pltfm_data sdhci_pltfm_data_kona = {
.ops = &sdhci_bcm_kona_ops,
.quirks = SDHCI_QUIRK_NO_CARD_NO_RESET |
SDHCI_QUIRK_BROKEN_TIMEOUT_VAL | SDHCI_QUIRK_32BIT_DMA_ADDR |
SDHCI_QUIRK_32BIT_DMA_SIZE | SDHCI_QUIRK_32BIT_ADMA_SIZE |
SDHCI_QUIRK_FORCE_BLK_SZ_2048 |
SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
};
static const struct of_device_id sdhci_bcm_kona_of_match[] = {
{ .compatible = "brcm,kona-sdhci"},
{ .compatible = "bcm,kona-sdhci"}, /* deprecated name */
{}
};
MODULE_DEVICE_TABLE(of, sdhci_bcm_kona_of_match);
static int sdhci_bcm_kona_probe(struct platform_device *pdev)
{
struct sdhci_bcm_kona_dev *kona_dev = NULL;
struct sdhci_pltfm_host *pltfm_priv;
struct device *dev = &pdev->dev;
struct sdhci_host *host;
int ret;
ret = 0;
host = sdhci_pltfm_init(pdev, &sdhci_pltfm_data_kona,
sizeof(*kona_dev));
if (IS_ERR(host))
return PTR_ERR(host);
dev_dbg(dev, "%s: inited. IOADDR=%p\n", __func__, host->ioaddr);
pltfm_priv = sdhci_priv(host);
kona_dev = sdhci_pltfm_priv(pltfm_priv);
mutex_init(&kona_dev->write_lock);
ret = mmc_of_parse(host->mmc);
if (ret)
goto err_pltfm_free;
if (!host->mmc->f_max) {
dev_err(&pdev->dev, "Missing max-freq for SDHCI cfg\n");
ret = -ENXIO;
goto err_pltfm_free;
}
/* Get and enable the core clock */
pltfm_priv->clk = devm_clk_get(dev, NULL);
if (IS_ERR(pltfm_priv->clk)) {
dev_err(dev, "Failed to get core clock\n");
ret = PTR_ERR(pltfm_priv->clk);
goto err_pltfm_free;
}
ret = clk_set_rate(pltfm_priv->clk, host->mmc->f_max);
if (ret) {
dev_err(dev, "Failed to set rate core clock\n");
goto err_pltfm_free;
}
ret = clk_prepare_enable(pltfm_priv->clk);
if (ret) {
dev_err(dev, "Failed to enable core clock\n");
goto err_pltfm_free;
}
dev_dbg(dev, "non-removable=%c\n",
mmc_card_is_removable(host->mmc) ? 'N' : 'Y');
dev_dbg(dev, "cd_gpio %c, wp_gpio %c\n",
(mmc_gpio_get_cd(host->mmc) != -ENOSYS) ? 'Y' : 'N',
(mmc_gpio_get_ro(host->mmc) != -ENOSYS) ? 'Y' : 'N');
if (!mmc_card_is_removable(host->mmc))
host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION;
dev_dbg(dev, "is_8bit=%c\n",
(host->mmc->caps & MMC_CAP_8_BIT_DATA) ? 'Y' : 'N');
ret = sdhci_bcm_kona_sd_reset(host);
if (ret)
goto err_clk_disable;
sdhci_bcm_kona_sd_init(host);
ret = sdhci_add_host(host);
if (ret) {
dev_err(dev, "Failed sdhci_add_host\n");
goto err_reset;
}
/* if device is eMMC, emulate card insert right here */
if (!mmc_card_is_removable(host->mmc)) {
ret = sdhci_bcm_kona_sd_card_emulate(host, 1);
if (ret) {
dev_err(dev,
"unable to emulate card insertion\n");
goto err_remove_host;
}
}
/*
* Since the card detection GPIO interrupt is configured to be
* edge sensitive, check the initial GPIO value here, emulate
* only if the card is present
*/
if (mmc_gpio_get_cd(host->mmc) > 0)
sdhci_bcm_kona_sd_card_emulate(host, 1);
dev_dbg(dev, "initialized properly\n");
return 0;
err_remove_host:
sdhci_remove_host(host, 0);
err_reset:
sdhci_bcm_kona_sd_reset(host);
err_clk_disable:
clk_disable_unprepare(pltfm_priv->clk);
err_pltfm_free:
sdhci_pltfm_free(pdev);
dev_err(dev, "Probing of sdhci-pltfm failed: %d\n", ret);
return ret;
}
static struct platform_driver sdhci_bcm_kona_driver = {
.driver = {
.name = "sdhci-kona",
.pm = &sdhci_pltfm_pmops,
.of_match_table = sdhci_bcm_kona_of_match,
},
.probe = sdhci_bcm_kona_probe,
.remove = sdhci_pltfm_unregister,
};
module_platform_driver(sdhci_bcm_kona_driver);
MODULE_DESCRIPTION("SDHCI driver for Broadcom Kona platform");
MODULE_AUTHOR("Broadcom");
MODULE_LICENSE("GPL v2");
