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path: root/drivers/mmc/host/sdhci-bcm-kona.c
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Diffstat (limited to 'drivers/mmc/host/sdhci-bcm-kona.c')
-rw-r--r--drivers/mmc/host/sdhci-bcm-kona.c339
1 files changed, 339 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-bcm-kona.c b/drivers/mmc/host/sdhci-bcm-kona.c
new file mode 100644
index 000000000..2bd90fb35
--- /dev/null
+++ b/drivers/mmc/host/sdhci-bcm-kona.c
@@ -0,0 +1,339 @@
+/*
+ * 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;
+ }
+
+ if (clk_set_rate(pltfm_priv->clk, host->mmc->f_max) != 0) {
+ dev_err(dev, "Failed to set rate core clock\n");
+ goto err_pltfm_free;
+ }
+
+ if (clk_prepare_enable(pltfm_priv->clk) != 0) {
+ dev_err(dev, "Failed to enable core clock\n");
+ goto err_pltfm_free;
+ }
+
+ dev_dbg(dev, "non-removable=%c\n",
+ (host->mmc->caps & MMC_CAP_NONREMOVABLE) ? 'Y' : 'N');
+ 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 (host->mmc->caps & MMC_CAP_NONREMOVABLE)
+ 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 (host->mmc->caps & MMC_CAP_NONREMOVABLE) {
+ 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");