[PATCH] ARM: mmc: bcm281xx SDHCI driver
Jean-Christophe PLAGNIOL-VILLARD
plagnioj at jcrosoft.com
Fri May 10 20:26:58 EST 2013
On 00:29 Fri 10 May , Christian Daudt wrote:
> Thanks for the feedback.
>
> On 13-05-08 11:35 PM, Jean-Christophe PLAGNIOL-VILLARD wrote:
> >On 22:55 Wed 08 May , Christian Daudt wrote:
> >>Add SDHCI driver for the Broadcom 281xx SoCs. Also
> >>add bindings for it into bcm281xx dts files.
> >>Still missing:
> >> - power managemement
> >split the dts/dtsi in an other patch
> ok.
> >>Signed-off-by: Christian Daudt <csd at broadcom.com>
> >>
> >>diff --git a/arch/arm/configs/bcm_defconfig b/arch/arm/configs/bcm_defconfig
> >>index e3bf2d6..65edf6d 100644
> >>--- a/arch/arm/configs/bcm_defconfig
> >>+++ b/arch/arm/configs/bcm_defconfig
> >>@@ -78,6 +78,13 @@ CONFIG_BACKLIGHT_LCD_SUPPORT=y
> >> CONFIG_LCD_CLASS_DEVICE=y
> >> CONFIG_BACKLIGHT_CLASS_DEVICE=y
> >> # CONFIG_USB_SUPPORT is not set
> >>+CONFIG_MMC=y
> >>+CONFIG_MMC_UNSAFE_RESUME=y
> >>+CONFIG_MMC_BLOCK_MINORS=32
> >>+CONFIG_MMC_TEST=y
> >>+CONFIG_MMC_SDHCI=y
> >>+CONFIG_MMC_SDHCI_PLTFM=y
> >>+CONFIG_MMC_SDHCI_BCM_KONA=y
> >> CONFIG_NEW_LEDS=y
> >> CONFIG_LEDS_CLASS=y
> >> CONFIG_LEDS_TRIGGERS=y
> >>diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> >>index d88219e..e067c5a 100644
> >>--- a/drivers/mmc/host/Kconfig
> >>+++ b/drivers/mmc/host/Kconfig
> >>@@ -238,6 +238,16 @@ config MMC_SDHCI_S3C_DMA
> >> YMMV.
> >>+config MMC_SDHCI_BCM_KONA
> >>+ tristate "SDHCI support on Broadcom KONA platform"
> >>+ depends on ARCH_BCM && MMC_SDHCI_PLTFM
> >select MMC_SDHCI_PLTFM
> >will be better
> Ok - changed it. Why is the select is better than the depends ?
> >>+
> >>+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.
> >>+ */
> >>+ udelay(1000);
> >really a udelay of 1ms
> I'm trying to clarify on whether this is really necessary but it
> does seem that this is the case. I'll send a follow-up patch if I
> manage to get confirmation on a smaller safe number.
a smaller delay will be better otherwise a msleep(1)
Best Regards,
J.
>
> >>+ 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.
> >>+ */
> >>+ udelay(1000);
> >ditto
> see above
> >>+ 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 = pltfm_priv->priv;
> >>+ u32 val;
> >>+ unsigned long flags;
> >>+
> >>+ /* this function can be called from various contexts including ISR */
> >>+ spin_lock_irqsave(&host->lock, flags);
> >>+ /* Ensure SD bus scanning to detect media change */
> >>+ host->mmc->rescan_disable = 0;
> >>+
> >>+ /*
> >>+ * 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
> >>+ */
> >>+ udelay(20);
> >>+ val = sdhci_readl(host, KONA_SDHOST_CORESTAT);
> >>+
> >>+ if (insert) {
> >>+ if (kona_dev->cfg->wp_gpio >= 0) {
> >gpio_is_valid
> done
> >>+ int wp_status = gpio_get_value(kona_dev->cfg->wp_gpio);
> >>+
> >>+ if (wp_status)
> >>+ val |= KONA_SDHOST_WP;
> >>+ else
> >>+ val &= ~KONA_SDHOST_WP;
> >>+ }
> >>+
> >>+ 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);
> >>+ }
> >>+ spin_unlock_irqrestore(&host->lock, flags);
> >>+
> >>+ return 0;
> >>+}
> >>+
> >>+/*
> >>+ * SD card detection interrupt handler
> >>+ */
> >>+static irqreturn_t sdhci_bcm_kona_pltfm_cd_interrupt(int irq, void *host)
> >>+{
> >>+ struct sdhci_pltfm_host *pltfm_priv = sdhci_priv(host);
> >>+ struct sdhci_bcm_kona_dev *kona_dev = pltfm_priv->priv;
> >>+
> >>+ if (gpio_get_value_cansleep(kona_dev->cfg->cd_gpio) == 0) {
> >>+ pr_debug("card inserted\n");
> >dev_dbg
> done
> >>+ sdhci_bcm_kona_sd_card_emulate(host, 1);
> >>+ } else {
> >>+ pr_debug("card removed\n");
> >ditto
> done
> >>+static struct sdhci_bcm_kona_cfg * __init sdhci_bcm_kona_parse_dt(
> >>+ struct platform_device *pdev)
> >>+{
> >>+ struct sdhci_bcm_kona_cfg *cfg;
> >>+ struct device_node *np = pdev->dev.of_node;
> >>+ u32 temp;
> >>+
> >>+ if (!np)
> >>+ return NULL;
> >>+
> >>+ cfg = devm_kzalloc(&pdev->dev, sizeof(*cfg), GFP_KERNEL);
> >>+ if (!cfg) {
> >>+ dev_err(&pdev->dev, "Can't allocate platform cfg\n");
> >>+ return NULL;
> >>+ }
> >>+
> >>+ cfg->cd_gpio = of_get_named_gpio(np, "cd-gpios", 0);
> >>+ cfg->wp_gpio = of_get_named_gpio(np, "wp-gpios", 0);
> >>+ if (of_get_property(np, "non-removable", NULL))
> >>+ cfg->non_removable = 1;
> >use of_property_read_bool
> done
> >>+ /* Sleep for 128ms to allow debounce to stabilize */
> >>+ msleep(SD_DETECT_GPIO_DEBOUNCE_128MS);
> >>+ /* request irq for cd_gpio after the gpio debounce is
> >>+ * stabilized, otherwise, some bogus gpio interrupts might be
> >>+ * triggered.
> >>+ */
> >>+ irq = gpio_to_irq(kona_dev->cfg->cd_gpio);
> >>+ ret = devm_request_threaded_irq(dev,
> >>+ irq,
> >>+ NULL,
> >>+ sdhci_bcm_kona_pltfm_cd_interrupt,
> >>+ IRQF_TRIGGER_FALLING|
> >>+ IRQF_TRIGGER_RISING |
> >>+ IRQF_ONESHOT |
> >>+ IRQF_NO_SUSPEND, "sdio cd", host);
> >>+ if (ret) {
> >>+ dev_err(kona_dev->dev,
> >>+ "Unable to request card detection irq=%d"
> >>+ " for gpio=%d ret=%d\n",
> >put the sting of the dev_err on one line so we can grep
> merged it into single line
>
>
> Thanks,
> csd
>
>
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