1 files changed, 383 insertions, 0 deletions
diff --git a/drivers/usb/musb/mpfs.c b/drivers/usb/musb/mpfs.c
new file mode 100644
index 000000000000..587127abd30a
--- /dev/null
+++ b/drivers/usb/musb/mpfs.c
@@ -0,0 +1,383 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PolarFire SoC (MPFS) MUSB Glue Layer
+ *
+ * Copyright (c) 2020-2022 Microchip Corporation. All rights reserved.
+ * Based on {omap2430,tusb6010,ux500}.c
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/usb/usb_phy_generic.h>
+#include "musb_core.h"
+#include "musb_dma.h"
+
+#define MPFS_MUSB_MAX_EP_NUM	8
+#define MPFS_MUSB_RAM_BITS	12
+
+struct mpfs_glue {
+	struct device *dev;
+	struct platform_device *musb;
+	struct platform_device *phy;
+	struct clk *clk;
+};
+
+static const struct musb_fifo_cfg mpfs_musb_mode_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 = 512, },
+	{ .hw_ep_num = 2, .style = FIFO_RX, .maxpacket = 512, },
+	{ .hw_ep_num = 3, .style = FIFO_TX, .maxpacket = 512, },
+	{ .hw_ep_num = 3, .style = FIFO_RX, .maxpacket = 512, },
+	{ .hw_ep_num = 4, .style = FIFO_TX, .maxpacket = 1024, },
+	{ .hw_ep_num = 4, .style = FIFO_RX, .maxpacket = 4096, },
+};
+
+static const struct musb_hdrc_config mpfs_musb_hdrc_config = {
+	.fifo_cfg = mpfs_musb_mode_cfg,
+	.fifo_cfg_size = ARRAY_SIZE(mpfs_musb_mode_cfg),
+	.multipoint = true,
+	.dyn_fifo = true,
+	.num_eps = MPFS_MUSB_MAX_EP_NUM,
+	.ram_bits = MPFS_MUSB_RAM_BITS,
+};
+
+static void mpfs_musb_set_vbus(struct musb *musb, int is_on)
+{
+	u8 devctl;
+
+	/*
+	 * HDRC controls CPEN, but beware current surges during device
+	 * connect.  They can trigger transient overcurrent conditions
+	 * that must be ignored.
+	 */
+	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
+
+	if (is_on) {
+		musb->is_active = 1;
+		musb->xceiv->otg->default_a = 1;
+		musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
+		devctl |= MUSB_DEVCTL_SESSION;
+		MUSB_HST_MODE(musb);
+	} else {
+		musb->is_active = 0;
+
+		/*
+		 * NOTE:  skipping A_WAIT_VFALL -> A_IDLE and
+		 * jumping right to B_IDLE...
+		 */
+		musb->xceiv->otg->default_a = 0;
+		musb->xceiv->otg->state = OTG_STATE_B_IDLE;
+		devctl &= ~MUSB_DEVCTL_SESSION;
+
+		MUSB_DEV_MODE(musb);
+	}
+
+	musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
+
+	dev_dbg(musb->controller, "VBUS %s, devctl %02x\n",
+		usb_otg_state_string(musb->xceiv->otg->state),
+		musb_readb(musb->mregs, MUSB_DEVCTL));
+}
+
+#define	POLL_SECONDS	2
+
+static void otg_timer(struct timer_list *t)
+{
+	struct musb		*musb = timer_container_of(musb, t,
+							      dev_timer);
+	void __iomem		*mregs = musb->mregs;
+	u8			devctl;
+	unsigned long		flags;
+
+	/*
+	 * We poll because PolarFire SoC won't expose several OTG-critical
+	 * status change events (from the transceiver) otherwise.
+	 */
+	devctl = musb_readb(mregs, MUSB_DEVCTL);
+	dev_dbg(musb->controller, "Poll devctl %02x (%s)\n", devctl,
+		usb_otg_state_string(musb->xceiv->otg->state));
+
+	spin_lock_irqsave(&musb->lock, flags);
+	switch (musb->xceiv->otg->state) {
+	case OTG_STATE_A_WAIT_BCON:
+		devctl &= ~MUSB_DEVCTL_SESSION;
+		musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
+
+		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
+		if (devctl & MUSB_DEVCTL_BDEVICE) {
+			musb->xceiv->otg->state = OTG_STATE_B_IDLE;
+			MUSB_DEV_MODE(musb);
+			mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
+		} else {
+			musb->xceiv->otg->state = OTG_STATE_A_IDLE;
+			MUSB_HST_MODE(musb);
+		}
+		break;
+	case OTG_STATE_A_WAIT_VFALL:
+		if (devctl & MUSB_DEVCTL_VBUS) {
+			mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
+			break;
+		}
+		musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
+		break;
+	case OTG_STATE_B_IDLE:
+		/*
+		 * There's no ID-changed IRQ, so we have no good way to tell
+		 * when to switch to the A-Default state machine (by setting
+		 * the DEVCTL.Session bit).
+		 *
+		 * Workaround:  whenever we're in B_IDLE, try setting the
+		 * session flag every few seconds.  If it works, ID was
+		 * grounded and we're now in the A-Default state machine.
+		 *
+		 * NOTE: setting the session flag is _supposed_ to trigger
+		 * SRP but clearly it doesn't.
+		 */
+		musb_writeb(mregs, MUSB_DEVCTL, devctl | MUSB_DEVCTL_SESSION);
+		devctl = musb_readb(mregs, MUSB_DEVCTL);
+		if (devctl & MUSB_DEVCTL_BDEVICE)
+			mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
+		else
+			musb->xceiv->otg->state = OTG_STATE_A_IDLE;
+		break;
+	default:
+		break;
+	}
+	spin_unlock_irqrestore(&musb->lock, flags);
+}
+
+static void __maybe_unused mpfs_musb_try_idle(struct musb *musb, unsigned long timeout)
+{
+	static unsigned long last_timer;
+
+	if (timeout == 0)
+		timeout = jiffies + msecs_to_jiffies(3);
+
+	/* Never idle if active, or when VBUS timeout is not set as host */
+	if (musb->is_active || (musb->a_wait_bcon == 0 &&
+				musb->xceiv->otg->state == OTG_STATE_A_WAIT_BCON)) {
+		dev_dbg(musb->controller, "%s active, deleting timer\n",
+			usb_otg_state_string(musb->xceiv->otg->state));
+		timer_delete(&musb->dev_timer);
+		last_timer = jiffies;
+		return;
+	}
+
+	if (time_after(last_timer, timeout) && timer_pending(&musb->dev_timer)) {
+		dev_dbg(musb->controller, "Longer idle timer already pending, ignoring...\n");
+		return;
+	}
+	last_timer = timeout;
+
+	dev_dbg(musb->controller, "%s inactive, starting idle timer for %u ms\n",
+		usb_otg_state_string(musb->xceiv->otg->state),
+		jiffies_to_msecs(timeout - jiffies));
+	mod_timer(&musb->dev_timer, timeout);
+}
+
+static irqreturn_t mpfs_musb_interrupt(int irq, void *__hci)
+{
+	unsigned long flags;
+	irqreturn_t ret = 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);
+
+	if (musb->int_usb || musb->int_tx || musb->int_rx) {
+		musb_writeb(musb->mregs, MUSB_INTRUSB, musb->int_usb);
+		musb_writew(musb->mregs, MUSB_INTRTX, musb->int_tx);
+		musb_writew(musb->mregs, MUSB_INTRRX, musb->int_rx);
+		ret = musb_interrupt(musb);
+	}
+
+	/* Poll for ID change */
+	if (musb->xceiv->otg->state == OTG_STATE_B_IDLE)
+		mod_timer(&musb->dev_timer, jiffies + POLL_SECONDS * HZ);
+
+	spin_unlock_irqrestore(&musb->lock, flags);
+
+	return ret;
+}
+
+static int mpfs_musb_init(struct musb *musb)
+{
+	struct device *dev = musb->controller;
+
+	musb->xceiv = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
+	if (IS_ERR(musb->xceiv)) {
+		dev_err(dev, "HS UDC: no transceiver configured\n");
+		return PTR_ERR(musb->xceiv);
+	}
+
+	timer_setup(&musb->dev_timer, otg_timer, 0);
+
+	musb->dyn_fifo = true;
+	musb->isr = mpfs_musb_interrupt;
+
+	musb_platform_set_vbus(musb, 1);
+
+	return 0;
+}
+
+static int mpfs_musb_exit(struct musb *musb)
+{
+	timer_delete_sync(&musb->dev_timer);
+
+	return 0;
+}
+
+static const struct musb_platform_ops mpfs_ops = {
+	.quirks		= MUSB_DMA_INVENTRA,
+	.init		= mpfs_musb_init,
+	.exit		= mpfs_musb_exit,
+	.fifo_mode	= 2,
+#ifdef CONFIG_USB_INVENTRA_DMA
+	.dma_init	= musbhs_dma_controller_create,
+	.dma_exit	= musbhs_dma_controller_destroy,
+#endif
+#ifndef CONFIG_USB_MUSB_HOST
+	.try_idle	= mpfs_musb_try_idle,
+#endif
+	.set_vbus	= mpfs_musb_set_vbus
+};
+
+static int mpfs_probe(struct platform_device *pdev)
+{
+	struct musb_hdrc_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	struct mpfs_glue *glue;
+	struct platform_device *musb_pdev;
+	struct device *dev = &pdev->dev;
+	struct clk *clk;
+	int ret;
+
+	glue = devm_kzalloc(dev, sizeof(*glue), GFP_KERNEL);
+	if (!glue)
+		return -ENOMEM;
+
+	musb_pdev = platform_device_alloc("musb-hdrc", PLATFORM_DEVID_AUTO);
+	if (!musb_pdev) {
+		dev_err(dev, "failed to allocate musb device\n");
+		return -ENOMEM;
+	}
+
+	clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "failed to get clock\n");
+		ret = PTR_ERR(clk);
+		goto err_phy_release;
+	}
+
+	ret = clk_prepare_enable(clk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable clock\n");
+		goto err_phy_release;
+	}
+
+	musb_pdev->dev.parent = dev;
+	musb_pdev->dev.coherent_dma_mask = DMA_BIT_MASK(39);
+	musb_pdev->dev.dma_mask = &musb_pdev->dev.coherent_dma_mask;
+	device_set_of_node_from_dev(&musb_pdev->dev, dev);
+
+	glue->dev = dev;
+	glue->musb = musb_pdev;
+	glue->clk = clk;
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata) {
+		ret = -ENOMEM;
+		goto err_clk_disable;
+	}
+
+	pdata->config = &mpfs_musb_hdrc_config;
+	pdata->platform_ops = &mpfs_ops;
+
+	pdata->extvbus = device_property_read_bool(dev, "microchip,ext-vbus-drv");
+
+	pdata->mode = usb_get_dr_mode(dev);
+	if (pdata->mode == USB_DR_MODE_UNKNOWN) {
+		dev_info(dev, "No dr_mode property found, defaulting to otg\n");
+		pdata->mode = USB_DR_MODE_OTG;
+	}
+
+	glue->phy = usb_phy_generic_register();
+	if (IS_ERR(glue->phy)) {
+		dev_err(dev, "failed to register usb-phy %ld\n",
+			PTR_ERR(glue->phy));
+		ret = PTR_ERR(glue->phy);
+		goto err_clk_disable;
+	}
+
+	platform_set_drvdata(pdev, glue);
+
+	ret = platform_device_add_resources(musb_pdev, pdev->resource, pdev->num_resources);
+	if (ret) {
+		dev_err(dev, "failed to add resources\n");
+		goto err_clk_disable;
+	}
+
+	ret = platform_device_add_data(musb_pdev, pdata, sizeof(*pdata));
+	if (ret) {
+		dev_err(dev, "failed to add platform_data\n");
+		goto err_clk_disable;
+	}
+
+	ret = platform_device_add(musb_pdev);
+	if (ret) {
+		dev_err(dev, "failed to register musb device\n");
+		goto err_clk_disable;
+	}
+
+	dev_info(&pdev->dev, "Registered MPFS MUSB driver\n");
+	return 0;
+
+err_clk_disable:
+	clk_disable_unprepare(clk);
+
+err_phy_release:
+	usb_phy_generic_unregister(glue->phy);
+	platform_device_put(musb_pdev);
+	return ret;
+}
+
+static void mpfs_remove(struct platform_device *pdev)
+{
+	struct mpfs_glue *glue = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(glue->clk);
+	platform_device_unregister(glue->musb);
+	usb_phy_generic_unregister(pdev);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id mpfs_id_table[] = {
+	{ .compatible = "microchip,mpfs-musb" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, mpfs_id_table);
+#endif
+
+static struct platform_driver mpfs_musb_driver = {
+	.probe = mpfs_probe,
+	.remove = mpfs_remove,
+	.driver = {
+		.name = "mpfs-musb",
+		.of_match_table = of_match_ptr(mpfs_id_table)
+	},
+};
+
+module_platform_driver(mpfs_musb_driver);
+
+MODULE_DESCRIPTION("PolarFire SoC MUSB Glue Layer");
+MODULE_LICENSE("GPL");