usb: musb: add support for JZ4740 usb device controller

Add support for Ingenic JZ4740 USB Device Controller through a
specific musb glue layer.

JZ4740 UDC not being OTG compatible and missing some hardware
registers, this musb glue layer is written from scratch to be used in
gadget mode only and take silicon design specifics into account.

Signed-off-by: Apelete Seketeli <apelete@seketeli.net>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

3 files changed, 209 insertions, 1 deletions

diff --git a/drivers/usb/musb/Kconfig b/drivers/usb/musb/Kconfig
index 57dfc0cedb00..14d7e725c2ff 100644
--- a/drivers/usb/musb/Kconfig
+++ b/drivers/usb/musb/Kconfig
@@ -93,6 +93,12 @@ config USB_MUSB_BLACKFIN
 config USB_MUSB_UX500
         tristate "Ux500 platforms"
 
+config USB_MUSB_JZ4740
+        tristate "JZ4740"
+        depends on MACH_JZ4740 || COMPILE_TEST
+        depends on USB_MUSB_GADGET
+        depends on USB_OTG_BLACKLIST_HUB
+
 endchoice
 
 config USB_MUSB_AM335X_CHILD
@@ -100,7 +106,7 @@ config USB_MUSB_AM335X_CHILD
 
 choice
         prompt 'MUSB DMA mode'
-        default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM
+        default MUSB_PIO_ONLY if ARCH_MULTIPLATFORM || USB_MUSB_JZ4740
         default USB_UX500_DMA if USB_MUSB_UX500
         default USB_INVENTRA_DMA if USB_MUSB_OMAP2PLUS || USB_MUSB_BLACKFIN
         default USB_TI_CPPI_DMA if USB_MUSB_DAVINCI
diff --git a/drivers/usb/musb/Makefile b/drivers/usb/musb/Makefile
index c5ea5c6dc169..ba495018b416 100644
--- a/drivers/usb/musb/Makefile
+++ b/drivers/usb/musb/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_USB_MUSB_DAVINCI)			+= davinci.o
 obj-$(CONFIG_USB_MUSB_DA8XX)                    += da8xx.o
 obj-$(CONFIG_USB_MUSB_BLACKFIN)                 += blackfin.o
 obj-$(CONFIG_USB_MUSB_UX500)                    += ux500.o
+obj-$(CONFIG_USB_MUSB_JZ4740)                   += jz4740.o
 
 
 obj-$(CONFIG_USB_MUSB_AM335X_CHILD)             += musb_am335x.o
diff --git a/drivers/usb/musb/jz4740.c b/drivers/usb/musb/jz4740.c
new file mode 100644
index 000000000000..5f30537f1927
--- /dev/null
+++ b/drivers/usb/musb/jz4740.c
@@ -0,0 +1,201 @@
+/*
+ * Ingenic JZ4740 "glue layer"
+ *
+ * Copyright (C) 2013, Apelete Seketeli <apelete@seketeli.net>
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include "musb_core.h"
+
+struct jz4740_glue {
+        struct device           *dev;
+        struct platform_device  *musb;
+        struct clk              *clk;
+};
+
+static irqreturn_t jz4740_musb_interrupt(int irq, void *__hci)
+{
+        unsigned long   flags;
+        irqreturn_t     retval = IRQ_NONE;
+        struct musb     *musb = __hci;
+
+        spin_lock_irqsave(&musb->lock, flags);
+
+        musb->int_usb = musb_readb(musb->mregs, MUSB_INTRUSB);
+        musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX);
+        musb->int_rx = musb_readw(musb->mregs, MUSB_INTRRX);
+
+        /*
+         * The controller is gadget only, the state of the host mode IRQ bits is
+         * undefined. Mask them to make sure that the musb driver core will
+         * never see them set
+         */
+        musb->int_usb &= MUSB_INTR_SUSPEND | MUSB_INTR_RESUME |
+            MUSB_INTR_RESET | MUSB_INTR_SOF;
+
+        if (musb->int_usb || musb->int_tx || musb->int_rx)
+                retval = musb_interrupt(musb);
+
+        spin_unlock_irqrestore(&musb->lock, flags);
+
+        return retval;
+}
+
+static struct musb_fifo_cfg jz4740_musb_fifo_cfg[] = {
+{ .hw_ep_num = 1, .style = FIFO_TX, .maxpacket = 512, },
+{ .hw_ep_num = 1, .style = FIFO_RX, .maxpacket = 512, },
+{ .hw_ep_num = 2, .style = FIFO_TX, .maxpacket = 64, },
+};
+
+static struct musb_hdrc_config jz4740_musb_config = {
+        /* Silicon does not implement USB OTG. */
+        .multipoint = 0,
+        /* Max EPs scanned, driver will decide which EP can be used. */
+        .num_eps    = 4,
+        /* RAMbits needed to configure EPs from table */
+        .ram_bits   = 9,
+        .fifo_cfg = jz4740_musb_fifo_cfg,
+        .fifo_cfg_size = ARRAY_SIZE(jz4740_musb_fifo_cfg),
+};
+
+static struct musb_hdrc_platform_data jz4740_musb_platform_data = {
+        .mode   = MUSB_PERIPHERAL,
+        .config = &jz4740_musb_config,
+};
+
+static int jz4740_musb_init(struct musb *musb)
+{
+        musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
+        if (!musb->xceiv) {
+                pr_err("HS UDC: no transceiver configured\n");
+                return -ENODEV;
+        }
+
+        /* Silicon does not implement ConfigData register.
+         * Set dyn_fifo to avoid reading EP config from hardware.
+         */
+        musb->dyn_fifo = true;
+
+        musb->isr = jz4740_musb_interrupt;
+
+        return 0;
+}
+
+static int jz4740_musb_exit(struct musb *musb)
+{
+        usb_put_phy(musb->xceiv);
+
+        return 0;
+}
+
+static const struct musb_platform_ops jz4740_musb_ops = {
+        .init           = jz4740_musb_init,
+        .exit           = jz4740_musb_exit,
+};
+
+static int jz4740_probe(struct platform_device *pdev)
+{
+        struct musb_hdrc_platform_data  *pdata = &jz4740_musb_platform_data;
+        struct platform_device          *musb;
+        struct jz4740_glue              *glue;
+        struct clk                      *clk;
+        int                             ret;
+
+        glue = devm_kzalloc(&pdev->dev, sizeof(*glue), GFP_KERNEL);
+        if (!glue)
+                return -ENOMEM;
+
+        musb = platform_device_alloc("musb-hdrc", PLATFORM_DEVID_AUTO);
+        if (!musb) {
+                dev_err(&pdev->dev, "failed to allocate musb device\n");
+                return -ENOMEM;
+        }
+
+        clk = devm_clk_get(&pdev->dev, "udc");
+        if (IS_ERR(clk)) {
+                dev_err(&pdev->dev, "failed to get clock\n");
+                ret = PTR_ERR(clk);
+                goto err_platform_device_put;
+        }
+
+        ret = clk_prepare_enable(clk);
+        if (ret) {
+                dev_err(&pdev->dev, "failed to enable clock\n");
+                goto err_platform_device_put;
+        }
+
+        musb->dev.parent                = &pdev->dev;
+
+        glue->dev                       = &pdev->dev;
+        glue->musb                      = musb;
+        glue->clk                       = clk;
+
+        pdata->platform_ops             = &jz4740_musb_ops;
+
+        platform_set_drvdata(pdev, glue);
+
+        ret = platform_device_add_resources(musb, pdev->resource,
+                                            pdev->num_resources);
+        if (ret) {
+                dev_err(&pdev->dev, "failed to add resources\n");
+                goto err_clk_disable;
+        }
+
+        ret = platform_device_add_data(musb, pdata, sizeof(*pdata));
+        if (ret) {
+                dev_err(&pdev->dev, "failed to add platform_data\n");
+                goto err_clk_disable;
+        }
+
+        ret = platform_device_add(musb);
+        if (ret) {
+                dev_err(&pdev->dev, "failed to register musb device\n");
+                goto err_clk_disable;
+        }
+
+        return 0;
+
+err_clk_disable:
+        clk_disable_unprepare(clk);
+err_platform_device_put:
+        platform_device_put(musb);
+        return ret;
+}
+
+static int jz4740_remove(struct platform_device *pdev)
+{
+        struct jz4740_glue      *glue = platform_get_drvdata(pdev);
+
+        platform_device_unregister(glue->musb);
+        clk_disable_unprepare(glue->clk);
+
+        return 0;
+}
+
+static struct platform_driver jz4740_driver = {
+        .probe          = jz4740_probe,
+        .remove         = jz4740_remove,
+        .driver         = {
+                .name   = "musb-jz4740",
+        },
+};
+
+MODULE_DESCRIPTION("JZ4740 MUSB Glue Layer");
+MODULE_AUTHOR("Apelete Seketeli <apelete@seketeli.net>");
+MODULE_LICENSE("GPL v2");
+module_platform_driver(jz4740_driver);