Lee,

On Wed, May 13, 2015 at 7:37 AM, Lee Jones [off-list ref] wrote:

On Mon, 04 May 2015, Andrew Bresticker wrote:

quoted

Add an MFD driver for the XUSB host complex found on NVIDIA Tegra124
and later SoCs.

What else does it do besides USB?

Nothing - it's just the xHCI host controller and mailbox.  As I
mentioned in the binding document, the purpose of this is simply to
map and share the register set which is shared between the two
devices.

quoted

Signed-off-by: Andrew Bresticker <redacted>
Cc: Samuel Ortiz <redacted>
Cc: Lee Jones <redacted>
---
Changes from v7:
 - Have child nodes get non-shared memory and interrupts from DT.
 - Use of_platform_populate rather than mfd_add_devices.
 - Get rid of struct tegra_xusb.
New for v7.
---
 drivers/mfd/Kconfig      |  7 +++++
 drivers/mfd/Makefile     |  1 +
 drivers/mfd/tegra-xusb.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 83 insertions(+)
 create mode 100644 drivers/mfd/tegra-xusb.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index d5ad04d..61872b4 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig

@@ -1430,6 +1430,13 @@ config MFD_STW481X
        in various ST Microelectronics and ST-Ericsson embedded
        Nomadik series.

+config MFD_TEGRA_XUSB
+     tristate "NVIDIA Tegra XUSB"
+     depends on ARCH_TEGRA
+     select MFD_CORE
+     help
+       Support for the XUSB complex found on NVIDIA Tegra124 and later SoCs.
+
 menu "Multimedia Capabilities Port drivers"
      depends on ARCH_SA1100

diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 0e5cfeb..7588caf 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile

@@ -181,6 +181,7 @@ obj-$(CONFIG_MFD_HI6421_PMIC)     += hi6421-pmic-core.o
 obj-$(CONFIG_MFD_DLN2)               += dln2.o
 obj-$(CONFIG_MFD_RT5033)     += rt5033.o
 obj-$(CONFIG_MFD_SKY81452)   += sky81452.o
+obj-$(CONFIG_MFD_TEGRA_XUSB) += tegra-xusb.o

 intel-soc-pmic-objs          := intel_soc_pmic_core.o intel_soc_pmic_crc.o
 obj-$(CONFIG_INTEL_SOC_PMIC) += intel-soc-pmic.o

diff --git a/drivers/mfd/tegra-xusb.c b/drivers/mfd/tegra-xusb.c
new file mode 100644
index 0000000..e11fa23
--- /dev/null
+++ b/drivers/mfd/tegra-xusb.c

@@ -0,0 +1,75 @@
+/*
+ * NVIDIA Tegra XUSB MFD driver
+ *
+ * Copyright (C) 2015 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/core.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+static const struct of_device_id tegra_xusb_of_match[] = {
+     { .compatible = "nvidia,tegra124-xusb", },
+     {},
+};
+MODULE_DEVICE_TABLE(of, tegra_xusb_of_match);

If you're not using this to patch on, I'd prefer you place it next to
where it's first used i.e. down at the bottom of the file.

Ok.

quoted

+static struct regmap_config tegra_fpci_regmap_config = {
+     .reg_bits = 32,
+     .val_bits = 32,
+     .reg_stride = 4,
+};
+
+static int tegra_xusb_probe(struct platform_device *pdev)
+{
+     struct resource *res;
+     struct regmap *fpci_regs;
+     void __iomem *fpci_base;
+     int ret;
+
+     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+     fpci_base = devm_ioremap_resource(&pdev->dev, res);
+     if (IS_ERR(fpci_base))
+             return PTR_ERR(fpci_base);
+
+     tegra_fpci_regmap_config.max_register = res->end - res->start - 3;
+     fpci_regs = devm_regmap_init_mmio(&pdev->dev, fpci_base,
+                                       &tegra_fpci_regmap_config);
+     if (IS_ERR(fpci_regs)) {
+             ret = PTR_ERR(fpci_regs);
+             dev_err(&pdev->dev, "Failed to init regmap: %d\n", ret);
+             return ret;
+     }
+     platform_set_drvdata(pdev, fpci_regs);
+
+     ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
+     if (ret) {
+             dev_err(&pdev->dev, "Failed to add sub-devices: %d\n", ret);
+             return ret;
+     }
+
+     return 0;
+}
+
+static struct platform_driver tegra_xusb_driver = {
+     .probe = tegra_xusb_probe,

No .remove()?

It would be empty.

Thanks,
Andrew