/* * Texas Instruments DSPS platforms "glue layer" * * Copyright (C) 2012, by Texas Instruments * * Based on the am35x "glue layer" code. * * This file is part of the Inventra Controller Driver for Linux. * * The Inventra Controller Driver for Linux is free software; you * can redistribute it and/or modify it under the terms of the GNU * General Public License version 2 as published by the Free Software * Foundation. * * The Inventra Controller Driver for Linux is distributed in * the hope that it will be useful, but WITHOUT ANY WARRANTY; * without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public * License for more details. * * You should have received a copy of the GNU General Public License * along with The Inventra Controller Driver for Linux ; if not, * write to the Free Software Foundation, Inc., 59 Temple Place, * Suite 330, Boston, MA 02111-1307 USA * * musb_dsps.c will be a common file for all the TI DSPS platforms * such as dm64x, dm36x, dm35x, da8x, am35x and ti81x. * For now only ti81x is using this and in future davinci.c, am35x.c * da8xx.c would be merged to this file after testing. */ #include <linux/init.h> #include <linux/io.h> #include <linux/err.h> #include <linux/platform_device.h> #include <linux/dma-mapping.h> #include <linux/pm_runtime.h> #include <linux/module.h> #include <linux/usb/nop-usb-xceiv.h> #include <linux/platform_data/usb-omap.h> #include <linux/sizes.h> #include <linux/of.h> #include <linux/of_device.h> #include <linux/of_address.h> #include "musb_core.h" #ifdef CONFIG_OF static const struct of_device_id musb_dsps_of_match[]; #endif /** * avoid using musb_readx()/musb_writex() as glue layer should not be * dependent on musb core layer symbols. */ static inline u8 dsps_readb(const void __iomem *addr, unsigned offset) { return __raw_readb(addr + offset); } static inline u32 dsps_readl(const void __iomem *addr, unsigned offset) { return __raw_readl(addr + offset); } static inline void dsps_writeb(void __iomem *addr, unsigned offset, u8 data) { __raw_writeb(data, addr + offset); } static inline void dsps_writel(void __iomem *addr, unsigned offset, u32 data) { __raw_writel(data, addr + offset); } /** * DSPS musb wrapper register offset. * FIXME: This should be expanded to have all the wrapper registers from TI DSPS * musb ips. */ struct dsps_musb_wrapper { u16 revision; u16 control; u16 status; u16 eoi; u16 epintr_set; u16 epintr_clear; u16 epintr_status; u16 coreintr_set; u16 coreintr_clear; u16 coreintr_status; u16 phy_utmi; u16 mode; /* bit positions for control */ unsigned reset:5; /* bit positions for interrupt */ unsigned usb_shift:5; u32 usb_mask; u32 usb_bitmap; unsigned drvvbus:5; unsigned txep_shift:5; u32 txep_mask; u32 txep_bitmap; unsigned rxep_shift:5; u32 rxep_mask; u32 rxep_bitmap; /* bit positions for phy_utmi */ unsigned otg_disable:5; /* bit positions for mode */ unsigned iddig:5; /* miscellaneous stuff */ u32 musb_core_offset; u8 poll_seconds; /* number of musb instances */ u8 instances; }; /** * DSPS glue structure. */ struct dsps_glue { struct device *dev; struct platform_device *musb[2]; /* child musb pdev */ const struct dsps_musb_wrapper *wrp; /* wrapper register offsets */ struct timer_list timer[2]; /* otg_workaround timer */ unsigned long last_timer[2]; /* last timer data for each instance */ u32 __iomem *usb_ctrl[2]; }; #define DSPS_AM33XX_CONTROL_MODULE_PHYS_0 0x44e10620 #define DSPS_AM33XX_CONTROL_MODULE_PHYS_1 0x44e10628 static const resource_size_t dsps_control_module_phys[] = { DSPS_AM33XX_CONTROL_MODULE_PHYS_0, DSPS_AM33XX_CONTROL_MODULE_PHYS_1, }; #define USBPHY_CM_PWRDN (1 << 0) #define USBPHY_OTG_PWRDN (1 << 1) #define USBPHY_OTGVDET_EN (1 << 19) #define USBPHY_OTGSESSEND_EN (1 << 20) /** * musb_dsps_phy_control - phy on/off * @glue: struct dsps_glue * * @id: musb instance * @on: flag for phy to be switched on or off * * This is to enable the PHY using usb_ctrl register in system control * module space. * * XXX: This function will be removed once we have a seperate driver for * control module */ static void musb_dsps_phy_control(struct dsps_glue *glue, u8 id, u8 on) { u32 usbphycfg; usbphycfg = readl(glue->usb_ctrl[id]); if (on) { usbphycfg &= ~(USBPHY_CM_PWRDN | USBPHY_OTG_PWRDN); usbphycfg |= USBPHY_OTGVDET_EN | USBPHY_OTGSESSEND_EN; } else { usbphycfg |= USBPHY_CM_PWRDN | USBPHY_OTG_PWRDN; } writel(usbphycfg, glue->usb_ctrl[id]); } /** * dsps_musb_enable - enable interrupts */ static void dsps_musb_enable(struct musb *musb) { struct device *dev = musb->controller; struct platform_device *pdev = to_platform_device(dev->parent); struct dsps_glue *glue = platform_get_drvdata(pdev); const struct dsps_musb_wrapper *wrp = glue->wrp; void __iomem *reg_base = musb->ctrl_base; u32 epmask, coremask; /* Workaround: setup IRQs through both register sets. */ epmask = ((musb->epmask & wrp->txep_mask) << wrp->txep_shift) | ((musb->epmask & wrp->rxep_mask) << wrp->rxep_shift); coremask = (wrp->usb_bitmap & ~MUSB_INTR_SOF); dsps_writel(reg_base, wrp->epintr_set, epmask); dsps_writel(reg_base, wrp->coreintr_set, coremask); /* Force the DRVVBUS IRQ so we can start polling for ID change. */ dsps_writel(reg_base, wrp->coreintr_set, (1 << wrp->drvvbus) << wrp->usb_shift); } /** * dsps_musb_disable - disable HDRC and flush interrupts */ static void dsps_musb_disable(struct musb *musb) { struct device *dev = musb->controller; struct platform_device *pdev = to_platform_device(dev->parent); struct dsps_glue *glue = platform_get_drvdata(pdev); const struct dsps_musb_wrapper *wrp = glue->wrp; void __iomem *reg_base = musb->ctrl_base; dsps_writel(reg_base, wrp->coreintr_clear, wrp->usb_bitmap); dsps_writel(reg_base, wrp->epintr_clear, wrp->txep_bitmap | wrp->rxep_bitmap); dsps_writeb(musb->mregs, MUSB_DEVCTL, 0); dsps_writel(reg_base, wrp->eoi, 0); } static void otg_timer(unsigned long _musb) { struct musb *musb = (void *)_musb; void __iomem *mregs = musb->mregs; struct device *dev = musb->controller; struct platform_device *pdev = to_platform_device(dev); struct dsps_glue *glue = dev_get_drvdata(dev->parent); const struct dsps_musb_wrapper *wrp = glue->wrp; u8 devctl; unsigned long flags; /* * We poll because DSPS IP's won't expose several OTG-critical * status change events (from the transceiver) otherwise. */ devctl = dsps_readb(mregs, MUSB_DEVCTL); dev_dbg(musb->controller, "Poll devctl %02x (%s)\n", devctl, usb_otg_state_string(musb->xceiv->state)); spin_lock_irqsave(&musb->lock, flags); switch (musb->xceiv->state) { case OTG_STATE_A_WAIT_BCON: devctl &= ~MUSB_DEVCTL_SESSION; dsps_writeb(musb->mregs, MUSB_DEVCTL, devctl); devctl = dsps_readb(musb->mregs, MUSB_DEVCTL); if (devctl & MUSB_DEVCTL_BDEVICE) { musb->xceiv->state = OTG_STATE_B_IDLE; MUSB_DEV_MODE(musb); } else { musb->xceiv->state = OTG_STATE_A_IDLE; MUSB_HST_MODE(musb); } break; case OTG_STATE_A_WAIT_VFALL: musb->xceiv->state = OTG_STATE_A_WAIT_VRISE; dsps_writel(musb->ctrl_base, wrp->coreintr_set, MUSB_INTR_VBUSERROR << wrp->usb_shift); break; case OTG_STATE_B_IDLE: devctl = dsps_readb(mregs, MUSB_DEVCTL); if (devctl & MUSB_DEVCTL_BDEVICE) mod_timer(&glue->timer[pdev->id], jiffies + wrp->poll_seconds * HZ); else musb->xceiv->state = OTG_STATE_A_IDLE; break; default: break; } spin_unlock_irqrestore(&musb->lock, flags); } static void dsps_musb_try_idle(struct musb *musb, unsigned long timeout) { struct device *dev = musb->controller; struct platform_device *pdev = to_platform_device(dev); struct dsps_glue *glue = dev_get_drvdata(dev->parent); 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->state == OTG_STATE_A_WAIT_BCON)) { dev_dbg(musb->controller, "%s active, deleting timer\n", usb_otg_state_string(musb->xceiv->state)); del_timer(&glue->timer[pdev->id]); glue->last_timer[pdev->id] = jiffies; return; } if (time_after(glue->last_timer[pdev->id], timeout) && timer_pending(&glue->timer[pdev->id])) { dev_dbg(musb->controller, "Longer idle timer already pending, ignoring...\n"); return; } glue->last_timer[pdev->id] = timeout; dev_dbg(musb->controller, "%s inactive, starting idle timer for %u ms\n", usb_otg_state_string(musb->xceiv->state), jiffies_to_msecs(timeout - jiffies)); mod_timer(&glue->timer[pdev->id], timeout); } static irqreturn_t dsps_interrupt(int irq, void *hci) { struct musb *musb = hci; void __iomem *reg_base = musb->ctrl_base; struct device *dev = musb->controller; struct platform_device *pdev = to_platform_device(dev); struct dsps_glue *glue = dev_get_drvdata(dev->parent); const struct dsps_musb_wrapper *wrp = glue->wrp; unsigned long flags; irqreturn_t ret = IRQ_NONE; u32 epintr, usbintr; spin_lock_irqsave(&musb->lock, flags); /* Get endpoint interrupts */ epintr = dsps_readl(reg_base, wrp->epintr_status); musb->int_rx = (epintr & wrp->rxep_bitmap) >> wrp->rxep_shift; musb->int_tx = (epintr & wrp->txep_bitmap) >> wrp->txep_shift; if (epintr) dsps_writel(reg_base, wrp->epintr_status, epintr); /* Get usb core interrupts */ usbintr = dsps_readl(reg_base, wrp->coreintr_status); if (!usbintr && !epintr) goto eoi; musb->int_usb = (usbintr & wrp->usb_bitmap) >> wrp->usb_shift; if (usbintr) dsps_writel(reg_base, wrp->coreintr_status, usbintr); dev_dbg(musb->controller, "usbintr (%x) epintr(%x)\n", usbintr, epintr); /* * DRVVBUS IRQs are the only proxy we have (a very poor one!) for * DSPS IP's missing ID change IRQ. We need an ID change IRQ to * switch appropriately between halves of the OTG state machine. * Managing DEVCTL.SESSION per Mentor docs requires that we know its * value but DEVCTL.BDEVICE is invalid without DEVCTL.SESSION set. * Also, DRVVBUS pulses for SRP (but not at 5V) ... */ if (is_host_active(musb) && usbintr & MUSB_INTR_BABBLE) pr_info("CAUTION: musb: Babble Interrupt Occurred\n"); if (usbintr & ((1 << wrp->drvvbus) << wrp->usb_shift)) { int drvvbus = dsps_readl(reg_base, wrp->status); void __iomem *mregs = musb->mregs; u8 devctl = dsps_readb(mregs, MUSB_DEVCTL); int err; err = musb->int_usb & MUSB_INTR_VBUSERROR; if (err) { /* * The Mentor core doesn't debounce VBUS as needed * to cope with device connect current spikes. This * means it's not uncommon for bus-powered devices * to get VBUS errors during enumeration. * * This is a workaround, but newer RTL from Mentor * seems to allow a better one: "re"-starting sessions * without waiting for VBUS to stop registering in * devctl. */ musb->int_usb &= ~MUSB_INTR_VBUSERROR; musb->xceiv->state = OTG_STATE_A_WAIT_VFALL; mod_timer(&glue->timer[pdev->id], jiffies + wrp->poll_seconds * HZ); WARNING("VBUS error workaround (delay coming)\n"); } else if (drvvbus) { musb->is_active = 1; MUSB_HST_MODE(musb); musb->xceiv->otg->default_a = 1; musb->xceiv->state = OTG_STATE_A_WAIT_VRISE; del_timer(&glue->timer[pdev->id]); } else { musb->is_active = 0; MUSB_DEV_MODE(musb); musb->xceiv->otg->default_a = 0; musb->xceiv->state = OTG_STATE_B_IDLE; } /* NOTE: this must complete power-on within 100 ms. */ dev_dbg(musb->controller, "VBUS %s (%s)%s, devctl %02x\n", drvvbus ? "on" : "off", usb_otg_state_string(musb->xceiv->state), err ? " ERROR" : "", devctl); ret = IRQ_HANDLED; } if (musb->int_tx || musb->int_rx || musb->int_usb) ret |= musb_interrupt(musb); eoi: /* EOI needs to be written for the IRQ to be re-asserted. */ if (ret == IRQ_HANDLED || epintr || usbintr) dsps_writel(reg_base, wrp->eoi, 1); /* Poll for ID change */ if (musb->xceiv->state == OTG_STATE_B_IDLE) mod_timer(&glue->timer[pdev->id], jiffies + wrp->poll_seconds * HZ); spin_unlock_irqrestore(&musb->lock, flags); return ret; } static int dsps_musb_init(struct musb *musb) { struct device *dev = musb->controller; struct platform_device *pdev = to_platform_device(dev); struct dsps_glue *glue = dev_get_drvdata(dev->parent); const struct dsps_musb_wrapper *wrp = glue->wrp; void __iomem *reg_base = musb->ctrl_base; u32 rev, val; int status; /* mentor core register starts at offset of 0x400 from musb base */ musb->mregs += wrp->musb_core_offset; /* NOP driver needs change if supporting dual instance */ usb_nop_xceiv_register(); musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2); if (IS_ERR_OR_NULL(musb->xceiv)) return -EPROBE_DEFER; /* Returns zero if e.g. not clocked */ rev = dsps_readl(reg_base, wrp->revision); if (!rev) { status = -ENODEV; goto err0; } setup_timer(&glue->timer[pdev->id], otg_timer, (unsigned long) musb); /* Reset the musb */ dsps_writel(reg_base, wrp->control, (1 << wrp->reset)); /* Start the on-chip PHY and its PLL. */ musb_dsps_phy_control(glue, pdev->id, 1); musb->isr = dsps_interrupt; /* reset the otgdisable bit, needed for host mode to work */ val = dsps_readl(reg_base, wrp->phy_utmi); val &= ~(1 << wrp->otg_disable); dsps_writel(musb->ctrl_base, wrp->phy_utmi, val); /* clear level interrupt */ dsps_writel(reg_base, wrp->eoi, 0); return 0; err0: usb_put_phy(musb->xceiv); usb_nop_xceiv_unregister(); return status; } static int dsps_musb_exit(struct musb *musb) { struct device *dev = musb->controller; struct platform_device *pdev = to_platform_device(dev); struct dsps_glue *glue = dev_get_drvdata(dev->parent); del_timer_sync(&glue->timer[pdev->id]); /* Shutdown the on-chip PHY and its PLL. */ musb_dsps_phy_control(glue, pdev->id, 0); /* NOP driver needs change if supporting dual instance */ usb_put_phy(musb->xceiv); usb_nop_xceiv_unregister(); return 0; } static struct musb_platform_ops dsps_ops = { .init = dsps_musb_init, .exit = dsps_musb_exit, .enable = dsps_musb_enable, .disable = dsps_musb_disable, .try_idle = dsps_musb_try_idle, }; static u64 musb_dmamask = DMA_BIT_MASK(32); static int dsps_create_musb_pdev(struct dsps_glue *glue, u8 id) { struct device *dev = glue->dev; struct platform_device *pdev = to_platform_device(dev); struct musb_hdrc_platform_data *pdata = dev->platform_data; struct device_node *np = pdev->dev.of_node; struct musb_hdrc_config *config; struct platform_device *musb; struct resource *res; struct resource resources[2]; char res_name[11]; int ret; resources[0].start = dsps_control_module_phys[id]; resources[0].end = resources[0].start + SZ_4 - 1; resources[0].flags = IORESOURCE_MEM; glue->usb_ctrl[id] = devm_ioremap_resource(&pdev->dev, resources); if (IS_ERR(glue->usb_ctrl[id])) { ret = PTR_ERR(glue->usb_ctrl[id]); goto err0; } /* first resource is for usbss, so start index from 1 */ res = platform_get_resource(pdev, IORESOURCE_MEM, id + 1); if (!res) { dev_err(dev, "failed to get memory for instance %d\n", id); ret = -ENODEV; goto err0; } res->parent = NULL; resources[0] = *res; /* first resource is for usbss, so start index from 1 */ res = platform_get_resource(pdev, IORESOURCE_IRQ, id + 1); if (!res) { dev_err(dev, "failed to get irq for instance %d\n", id); ret = -ENODEV; goto err0; } res->parent = NULL; resources[1] = *res; resources[1].name = "mc"; /* allocate the child platform device */ musb = platform_device_alloc("musb-hdrc", PLATFORM_DEVID_AUTO); if (!musb) { dev_err(dev, "failed to allocate musb device\n"); ret = -ENOMEM; goto err0; } musb->dev.parent = dev; musb->dev.dma_mask = &musb_dmamask; musb->dev.coherent_dma_mask = musb_dmamask; glue->musb[id] = musb; ret = platform_device_add_resources(musb, resources, 2); if (ret) { dev_err(dev, "failed to add resources\n"); goto err2; } if (np) { pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); if (!pdata) { dev_err(&pdev->dev, "failed to allocate musb platfrom data\n"); ret = -ENOMEM; goto err2; } config = devm_kzalloc(&pdev->dev, sizeof(*config), GFP_KERNEL); if (!config) { dev_err(&pdev->dev, "failed to allocate musb hdrc config\n"); ret = -ENOMEM; goto err2; } of_property_read_u32(np, "num-eps", (u32 *)&config->num_eps); of_property_read_u32(np, "ram-bits", (u32 *)&config->ram_bits); snprintf(res_name, sizeof(res_name), "port%d-mode", id); of_property_read_u32(np, res_name, (u32 *)&pdata->mode); of_property_read_u32(np, "power", (u32 *)&pdata->power); config->multipoint = of_property_read_bool(np, "multipoint"); pdata->config = config; } pdata->platform_ops = &dsps_ops; ret = platform_device_add_data(musb, pdata, sizeof(*pdata)); if (ret) { dev_err(dev, "failed to add platform_data\n"); goto err2; } ret = platform_device_add(musb); if (ret) { dev_err(dev, "failed to register musb device\n"); goto err2; } return 0; err2: platform_device_put(musb); err0: return ret; } static int dsps_probe(struct platform_device *pdev) { const struct of_device_id *match; const struct dsps_musb_wrapper *wrp; struct dsps_glue *glue; struct resource *iomem; int ret, i; match = of_match_node(musb_dsps_of_match, pdev->dev.of_node); if (!match) { dev_err(&pdev->dev, "fail to get matching of_match struct\n"); ret = -EINVAL; goto err0; } wrp = match->data; /* allocate glue */ glue = kzalloc(sizeof(*glue), GFP_KERNEL); if (!glue) { dev_err(&pdev->dev, "unable to allocate glue memory\n"); ret = -ENOMEM; goto err0; } /* get memory resource */ iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!iomem) { dev_err(&pdev->dev, "failed to get usbss mem resourse\n"); ret = -ENODEV; goto err1; } glue->dev = &pdev->dev; glue->wrp = kmemdup(wrp, sizeof(*wrp), GFP_KERNEL); if (!glue->wrp) { dev_err(&pdev->dev, "failed to duplicate wrapper struct memory\n"); ret = -ENOMEM; goto err1; } platform_set_drvdata(pdev, glue); /* enable the usbss clocks */ pm_runtime_enable(&pdev->dev); ret = pm_runtime_get_sync(&pdev->dev); if (ret < 0) { dev_err(&pdev->dev, "pm_runtime_get_sync FAILED"); goto err2; } /* create the child platform device for all instances of musb */ for (i = 0; i < wrp->instances ; i++) { ret = dsps_create_musb_pdev(glue, i); if (ret != 0) { dev_err(&pdev->dev, "failed to create child pdev\n"); /* release resources of previously created instances */ for (i--; i >= 0 ; i--) platform_device_unregister(glue->musb[i]); goto err3; } } return 0; err3: pm_runtime_put(&pdev->dev); err2: pm_runtime_disable(&pdev->dev); kfree(glue->wrp); err1: kfree(glue); err0: return ret; } static int dsps_remove(struct platform_device *pdev) { struct dsps_glue *glue = platform_get_drvdata(pdev); const struct dsps_musb_wrapper *wrp = glue->wrp; int i; /* delete the child platform device */ for (i = 0; i < wrp->instances ; i++) platform_device_unregister(glue->musb[i]); /* disable usbss clocks */ pm_runtime_put(&pdev->dev); pm_runtime_disable(&pdev->dev); kfree(glue->wrp); kfree(glue); return 0; } #ifdef CONFIG_PM_SLEEP static int dsps_suspend(struct device *dev) { struct platform_device *pdev = to_platform_device(dev->parent); struct dsps_glue *glue = platform_get_drvdata(pdev); const struct dsps_musb_wrapper *wrp = glue->wrp; int i; for (i = 0; i < wrp->instances; i++) musb_dsps_phy_control(glue, i, 0); return 0; } static int dsps_resume(struct device *dev) { struct platform_device *pdev = to_platform_device(dev->parent); struct dsps_glue *glue = platform_get_drvdata(pdev); const struct dsps_musb_wrapper *wrp = glue->wrp; int i; for (i = 0; i < wrp->instances; i++) musb_dsps_phy_control(glue, i, 1); return 0; } #endif static SIMPLE_DEV_PM_OPS(dsps_pm_ops, dsps_suspend, dsps_resume); static const struct dsps_musb_wrapper ti81xx_driver_data = { .revision = 0x00, .control = 0x14, .status = 0x18, .eoi = 0x24, .epintr_set = 0x38, .epintr_clear = 0x40, .epintr_status = 0x30, .coreintr_set = 0x3c, .coreintr_clear = 0x44, .coreintr_status = 0x34, .phy_utmi = 0xe0, .mode = 0xe8, .reset = 0, .otg_disable = 21, .iddig = 8, .usb_shift = 0, .usb_mask = 0x1ff, .usb_bitmap = (0x1ff << 0), .drvvbus = 8, .txep_shift = 0, .txep_mask = 0xffff, .txep_bitmap = (0xffff << 0), .rxep_shift = 16, .rxep_mask = 0xfffe, .rxep_bitmap = (0xfffe << 16), .musb_core_offset = 0x400, .poll_seconds = 2, .instances = 1, }; static const struct platform_device_id musb_dsps_id_table[] = { { .name = "musb-ti81xx", .driver_data = (kernel_ulong_t) &ti81xx_driver_data, }, { }, /* Terminating Entry */ }; MODULE_DEVICE_TABLE(platform, musb_dsps_id_table); #ifdef CONFIG_OF static const struct of_device_id musb_dsps_of_match[] = { { .compatible = "ti,musb-am33xx", .data = (void *) &ti81xx_driver_data, }, { }, }; MODULE_DEVICE_TABLE(of, musb_dsps_of_match); #endif static struct platform_driver dsps_usbss_driver = { .probe = dsps_probe, .remove = dsps_remove, .driver = { .name = "musb-dsps", .pm = &dsps_pm_ops, .of_match_table = of_match_ptr(musb_dsps_of_match), }, .id_table = musb_dsps_id_table, }; MODULE_DESCRIPTION("TI DSPS MUSB Glue Layer"); MODULE_AUTHOR("Ravi B <ravibabu@ti.com>"); MODULE_AUTHOR("Ajay Kumar Gupta <ajay.gupta@ti.com>"); MODULE_LICENSE("GPL v2"); static int __init dsps_init(void) { return platform_driver_register(&dsps_usbss_driver); } subsys_initcall(dsps_init); static void __exit dsps_exit(void) { platform_driver_unregister(&dsps_usbss_driver); } module_exit(dsps_exit);