[PATCH 1/4] mmc: sdhci: add a driver for Berlin SoCs

Thu Apr 17 06:33:59 PDT 2014

Sebastian,

On Wed, Apr 16, 2014 at 04:26:06PM +0200, Sebastian Hesselbarth wrote:
> On 04/16/2014 02:40 PM, Antoine Ténart wrote:
> >Add a Driver to support the SDHCI controller of the Marvell Berlin SoCs.
> >This controller supports 3 sockets.
> 
> nit: Isn't it three controller with one socket each?

It's a little bit confusing, there are 3 different register regions and
I can see 3 separate data lines but, I quote: "The SD host controller
supports three sockets".

Maybe Jisheng can advise on that matter ?

> 
> >Signed-off-by: Antoine Ténart <antoine.tenart at free-electrons.com>
> >---
> >  drivers/mmc/host/Kconfig        |  11 ++++
> >  drivers/mmc/host/Makefile       |   1 +
> >  drivers/mmc/host/sdhci-berlin.c | 129 ++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 141 insertions(+)
> >  create mode 100644 drivers/mmc/host/sdhci-berlin.c
> >
> >diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> >index 1384f67abe21..42db70031eb2 100644
> >--- a/drivers/mmc/host/Kconfig
> >+++ b/drivers/mmc/host/Kconfig
> >@@ -283,6 +283,17 @@ config MMC_SDHCI_BCM2835
> >
> >  	  If unsure, say N.
> >
> >+config MMC_SDHCI_BERLIN
> >+	tristate "Marvell Berlin SD/MMC Host Controller support"
> >+	depends on ARCH_BERLIN
> >+	depends on MMC_SDHCI_PLTFM
> >+	select MMC_SDHCI_IO_ACCESSORS
> >+	help
> >+	  This selects the Berlin SD/MMC controller. If you have a Berlin
> >+	  platform with SD or MMC devices, say Y or M here.
> >+
> >+	  If unsure, say N.
> >+
> >  config MMC_OMAP
> >  	tristate "TI OMAP Multimedia Card Interface support"
> >  	depends on ARCH_OMAP
> >diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
> >index 3483b6b6b880..b0256290530c 100644
> >--- a/drivers/mmc/host/Makefile
> >+++ b/drivers/mmc/host/Makefile
> >@@ -64,6 +64,7 @@ obj-$(CONFIG_MMC_SDHCI_OF_ESDHC)	+= sdhci-of-esdhc.o
> >  obj-$(CONFIG_MMC_SDHCI_OF_HLWD)		+= sdhci-of-hlwd.o
> >  obj-$(CONFIG_MMC_SDHCI_BCM_KONA)	+= sdhci-bcm-kona.o
> >  obj-$(CONFIG_MMC_SDHCI_BCM2835)		+= sdhci-bcm2835.o
> >+obj-$(CONFIG_MMC_SDHCI_BERLIN)		+= sdhci-berlin.o
> >
> >  ifeq ($(CONFIG_CB710_DEBUG),y)
> >  	CFLAGS-cb710-mmc	+= -DDEBUG
> >diff --git a/drivers/mmc/host/sdhci-berlin.c b/drivers/mmc/host/sdhci-berlin.c
> >new file mode 100644
> >index 000000000000..ece8f7863937
> >--- /dev/null
> >+++ b/drivers/mmc/host/sdhci-berlin.c
> >@@ -0,0 +1,129 @@
> >+/*
> >+ * Marvell Berlin SDHCI driver
> >+ *
> >+ * Copyright (C) 2014 Marvell Technology Group Ltd.
> >+ *
> >+ * Antoine Ténart <antoine.tenart at free-electrons.com>
> >+ *
> >+ * This file is licensed under the terms of the GNU General Public
> >+ * License version 2. This program is licensed "as is" without any
> >+ * warranty of any kind, whether express or implied
> >+ */
> >+
> >+#include <linux/clk.h>
> >+#include <linux/err.h>
> >+#include <linux/io.h>
> >+#include <linux/mmc/host.h>
> >+#include <linux/module.h>
> >+#include <linux/of.h>
> >+#include <linux/of_device.h>
> >+
> >+#include "sdhci-pltfm.h"
> >+
> >+static struct sdhci_ops sdhci_berlin_ops = {
> >+	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
> >+};
> >+
> >+static struct sdhci_pltfm_data sdhci_berlin2_pdata = {
> >+	.quirks	= SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
> >+		  SDHCI_QUIRK_BROKEN_ADMA |
> >+		  SDHCI_QUIRK_BROKEN_TIMEOUT_VAL,
> >+	.ops = &sdhci_berlin_ops,
> >+};
> >+
> >+static struct sdhci_pltfm_data sdhci_berlin2q_pdata = {
> >+	.quirks	= SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
> >+		  SDHCI_QUIRK_INVERTED_WRITE_PROTECT |
> >+		  SDHCI_QUIRK_BROKEN_TIMEOUT_VAL,
> >+	.ops = &sdhci_berlin_ops,
> >+};
> >+
> >+static const struct of_device_id sdhci_berlin_of_match_table[] = {
> >+	{
> >+		.compatible = "marvell,berlin2-sdhci",
> >+		.data = &sdhci_berlin2_pdata,
> >+	},
> >+	{
> >+		.compatible = "marvell,berlin2cd-sdhci",
> >+		.data = &sdhci_berlin2_pdata,
> >+	},
> >+	{
> >+		.compatible = "marvell,berlin2q-sdhci",
> >+		.data = &sdhci_berlin2q_pdata,
> >+	},
> >+	{}
> >+};
> >+MODULE_DEVICE_TABLE(of, sdhci_berlin_of_match_table);
> >+
> >+static int sdhci_berlin_probe(struct platform_device *pdev)
> >+{
> >+	struct device *dev = &pdev->dev;
> >+	struct sdhci_host *host;
> >+	struct sdhci_pltfm_host *pltfm_host;
> >+	struct clk *clk;
> >+	const struct of_device_id *device =
> >+		of_match_device(sdhci_berlin_of_match_table, dev);
> >+	int ret;
> >+
> >+	host = sdhci_pltfm_init(pdev,
> >+				(struct sdhci_pltfm_data *)device->data, 0);
> >+	if (IS_ERR(host))
> >+		return PTR_ERR(host);
> >+
> >+	pltfm_host = sdhci_priv(host);
> >+
> >+	clk = devm_clk_get(dev, NULL);
> >+	if (IS_ERR(clk)) {
> >+		dev_err(dev, "could not get clock: %ld\n", PTR_ERR(clk));
> >+		ret = PTR_ERR(clk);
> >+		goto err_clk_get;
> >+	}
> >+
> >+	clk_prepare_enable(clk);
> >+	pltfm_host->clk = clk;
> >+
> >+	sdhci_get_of_property(pdev);
> >+
> >+	if (host->quirks & SDHCI_QUIRK_BROKEN_CARD_DETECTION)
> >+		host->mmc->caps |= MMC_CAP_NONREMOVABLE;
> 
> Documentation/devicetree/bindings/mmc/mmc.txt names "non-removable"
> as a standard property. Any chance we can shove this two lines above
> right into sdhci_get_of_property()?

Well, I gave it a try without this quirk and it seemed to work fine.
If we find out we do need it, I agree to add this quirk in
sdhci_get_of_property().

Antoine

> 
> Besides the other comments from Joe, this looks good to me,
> 
> Reviewed-by: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
> 
> >+
> >+	ret = sdhci_add_host(host);
> >+	if (ret)
> >+		goto err_add_host;
> >+
> >+	return 0;
> >+
> >+err_add_host:
> >+	clk_disable_unprepare(pltfm_host->clk);
> >+err_clk_get:
> >+	sdhci_pltfm_free(pdev);
> >+
> >+	return ret;
> >+}
> >+
> >+static int sdhci_berlin_remove(struct platform_device *pdev)
> >+{
> >+	struct sdhci_host *host = platform_get_drvdata(pdev);
> >+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> >+
> >+	sdhci_pltfm_unregister(pdev);
> >+	clk_disable_unprepare(pltfm_host->clk);
> >+
> >+	return 0;
> >+}
> >+
> >+static struct platform_driver sdhci_berlin_driver = {
> >+	.driver		= {
> >+		.name	= "berlin-sdhci",
> >+		.owner	= THIS_MODULE,
> >+		.pm	= SDHCI_PLTFM_PMOPS,
> >+		.of_match_table = sdhci_berlin_of_match_table,
> >+	},
> >+	.probe		= sdhci_berlin_probe,
> >+	.remove		= sdhci_berlin_remove,
> >+};
> >+module_platform_driver(sdhci_berlin_driver);
> >+
> >+MODULE_DESCRIPTION("SDHCI driver for Marvell Berlin SoC");
> >+MODULE_AUTHOR("Antoine Ténart <antoine.tenart at free-electrons.com>");
> >+MODULE_LICENSE("GPL");
> >
> 

-- 
Antoine Ténart, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com