linux/linux-5.4.31/drivers/usb/cdns3/drd.c

382 lines
8.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Cadence USBSS DRD Driver.
*
* Copyright (C) 2018-2019 Cadence.
* Copyright (C) 2019 Texas Instruments
*
* Author: Pawel Laszczak <pawell@cadence.com>
* Roger Quadros <rogerq@ti.com>
*
*
*/
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/iopoll.h>
#include <linux/usb/otg.h>
#include "gadget.h"
#include "drd.h"
#include "core.h"
/**
* cdns3_set_mode - change mode of OTG Core
* @cdns: pointer to context structure
* @mode: selected mode from cdns_role
*
* Returns 0 on success otherwise negative errno
*/
int cdns3_set_mode(struct cdns3 *cdns, enum usb_dr_mode mode)
{
int ret = 0;
u32 reg;
switch (mode) {
case USB_DR_MODE_PERIPHERAL:
break;
case USB_DR_MODE_HOST:
break;
case USB_DR_MODE_OTG:
dev_dbg(cdns->dev, "Set controller to OTG mode\n");
if (cdns->version == CDNS3_CONTROLLER_V1) {
reg = readl(&cdns->otg_v1_regs->override);
reg |= OVERRIDE_IDPULLUP;
writel(reg, &cdns->otg_v1_regs->override);
} else {
reg = readl(&cdns->otg_v0_regs->ctrl1);
reg |= OVERRIDE_IDPULLUP_V0;
writel(reg, &cdns->otg_v0_regs->ctrl1);
}
/*
* Hardware specification says: "ID_VALUE must be valid within
* 50ms after idpullup is set to '1" so driver must wait
* 50ms before reading this pin.
*/
usleep_range(50000, 60000);
break;
default:
dev_err(cdns->dev, "Unsupported mode of operation %d\n", mode);
return -EINVAL;
}
return ret;
}
int cdns3_get_id(struct cdns3 *cdns)
{
int id;
id = readl(&cdns->otg_regs->sts) & OTGSTS_ID_VALUE;
dev_dbg(cdns->dev, "OTG ID: %d", id);
return id;
}
int cdns3_get_vbus(struct cdns3 *cdns)
{
int vbus;
vbus = !!(readl(&cdns->otg_regs->sts) & OTGSTS_VBUS_VALID);
dev_dbg(cdns->dev, "OTG VBUS: %d", vbus);
return vbus;
}
int cdns3_is_host(struct cdns3 *cdns)
{
if (cdns->dr_mode == USB_DR_MODE_HOST)
return 1;
else if (!cdns3_get_id(cdns))
return 1;
return 0;
}
int cdns3_is_device(struct cdns3 *cdns)
{
if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL)
return 1;
else if (cdns->dr_mode == USB_DR_MODE_OTG)
if (cdns3_get_id(cdns))
return 1;
return 0;
}
/**
* cdns3_otg_disable_irq - Disable all OTG interrupts
* @cdns: Pointer to controller context structure
*/
static void cdns3_otg_disable_irq(struct cdns3 *cdns)
{
writel(0, &cdns->otg_regs->ien);
}
/**
* cdns3_otg_enable_irq - enable id and sess_valid interrupts
* @cdns: Pointer to controller context structure
*/
static void cdns3_otg_enable_irq(struct cdns3 *cdns)
{
writel(OTGIEN_ID_CHANGE_INT | OTGIEN_VBUSVALID_RISE_INT |
OTGIEN_VBUSVALID_FALL_INT, &cdns->otg_regs->ien);
}
/**
* cdns3_drd_switch_host - start/stop host
* @cdns: Pointer to controller context structure
* @on: 1 for start, 0 for stop
*
* Returns 0 on success otherwise negative errno
*/
int cdns3_drd_switch_host(struct cdns3 *cdns, int on)
{
int ret, val;
u32 reg = OTGCMD_OTG_DIS;
/* switch OTG core */
if (on) {
writel(OTGCMD_HOST_BUS_REQ | reg, &cdns->otg_regs->cmd);
dev_dbg(cdns->dev, "Waiting till Host mode is turned on\n");
ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
val & OTGSTS_XHCI_READY,
1, 100000);
if (ret) {
dev_err(cdns->dev, "timeout waiting for xhci_ready\n");
return ret;
}
} else {
writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
&cdns->otg_regs->cmd);
/* Waiting till H_IDLE state.*/
readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
!(val & OTGSTATE_HOST_STATE_MASK),
1, 2000000);
}
return 0;
}
/**
* cdns3_drd_switch_gadget - start/stop gadget
* @cdns: Pointer to controller context structure
* @on: 1 for start, 0 for stop
*
* Returns 0 on success otherwise negative errno
*/
int cdns3_drd_switch_gadget(struct cdns3 *cdns, int on)
{
int ret, val;
u32 reg = OTGCMD_OTG_DIS;
/* switch OTG core */
if (on) {
writel(OTGCMD_DEV_BUS_REQ | reg, &cdns->otg_regs->cmd);
dev_dbg(cdns->dev, "Waiting till Device mode is turned on\n");
ret = readl_poll_timeout_atomic(&cdns->otg_regs->sts, val,
val & OTGSTS_DEV_READY,
1, 100000);
if (ret) {
dev_err(cdns->dev, "timeout waiting for dev_ready\n");
return ret;
}
} else {
/*
* driver should wait at least 10us after disabling Device
* before turning-off Device (DEV_BUS_DROP)
*/
usleep_range(20, 30);
writel(OTGCMD_HOST_BUS_DROP | OTGCMD_DEV_BUS_DROP |
OTGCMD_DEV_POWER_OFF | OTGCMD_HOST_POWER_OFF,
&cdns->otg_regs->cmd);
/* Waiting till DEV_IDLE state.*/
readl_poll_timeout_atomic(&cdns->otg_regs->state, val,
!(val & OTGSTATE_DEV_STATE_MASK),
1, 2000000);
}
return 0;
}
/**
* cdns3_init_otg_mode - initialize drd controller
* @cdns: Pointer to controller context structure
*
* Returns 0 on success otherwise negative errno
*/
static int cdns3_init_otg_mode(struct cdns3 *cdns)
{
int ret = 0;
cdns3_otg_disable_irq(cdns);
/* clear all interrupts */
writel(~0, &cdns->otg_regs->ivect);
ret = cdns3_set_mode(cdns, USB_DR_MODE_OTG);
if (ret)
return ret;
cdns3_otg_enable_irq(cdns);
return ret;
}
/**
* cdns3_drd_update_mode - initialize mode of operation
* @cdns: Pointer to controller context structure
*
* Returns 0 on success otherwise negative errno
*/
int cdns3_drd_update_mode(struct cdns3 *cdns)
{
int ret = 0;
switch (cdns->dr_mode) {
case USB_DR_MODE_PERIPHERAL:
ret = cdns3_set_mode(cdns, USB_DR_MODE_PERIPHERAL);
break;
case USB_DR_MODE_HOST:
ret = cdns3_set_mode(cdns, USB_DR_MODE_HOST);
break;
case USB_DR_MODE_OTG:
ret = cdns3_init_otg_mode(cdns);
break;
default:
dev_err(cdns->dev, "Unsupported mode of operation %d\n",
cdns->dr_mode);
return -EINVAL;
}
return ret;
}
static irqreturn_t cdns3_drd_thread_irq(int irq, void *data)
{
struct cdns3 *cdns = data;
cdns3_hw_role_switch(cdns);
return IRQ_HANDLED;
}
/**
* cdns3_drd_irq - interrupt handler for OTG events
*
* @irq: irq number for cdns3 core device
* @data: structure of cdns3
*
* Returns IRQ_HANDLED or IRQ_NONE
*/
static irqreturn_t cdns3_drd_irq(int irq, void *data)
{
irqreturn_t ret = IRQ_NONE;
struct cdns3 *cdns = data;
u32 reg;
if (cdns->dr_mode != USB_DR_MODE_OTG)
return ret;
reg = readl(&cdns->otg_regs->ivect);
if (!reg)
return ret;
if (reg & OTGIEN_ID_CHANGE_INT) {
dev_dbg(cdns->dev, "OTG IRQ: new ID: %d\n",
cdns3_get_id(cdns));
ret = IRQ_WAKE_THREAD;
}
if (reg & (OTGIEN_VBUSVALID_RISE_INT | OTGIEN_VBUSVALID_FALL_INT)) {
dev_dbg(cdns->dev, "OTG IRQ: new VBUS: %d\n",
cdns3_get_vbus(cdns));
ret = IRQ_WAKE_THREAD;
}
writel(~0, &cdns->otg_regs->ivect);
return ret;
}
int cdns3_drd_init(struct cdns3 *cdns)
{
void __iomem *regs;
int ret = 0;
u32 state;
regs = devm_ioremap_resource(cdns->dev, &cdns->otg_res);
if (IS_ERR(regs))
return PTR_ERR(regs);
/* Detection of DRD version. Controller has been released
* in two versions. Both are similar, but they have same changes
* in register maps.
* The first register in old version is command register and it's read
* only, so driver should read 0 from it. On the other hand, in v1
* the first register contains device ID number which is not set to 0.
* Driver uses this fact to detect the proper version of
* controller.
*/
cdns->otg_v0_regs = regs;
if (!readl(&cdns->otg_v0_regs->cmd)) {
cdns->version = CDNS3_CONTROLLER_V0;
cdns->otg_v1_regs = NULL;
cdns->otg_regs = regs;
writel(1, &cdns->otg_v0_regs->simulate);
dev_info(cdns->dev, "DRD version v0 (%08x)\n",
readl(&cdns->otg_v0_regs->version));
} else {
cdns->otg_v0_regs = NULL;
cdns->otg_v1_regs = regs;
cdns->otg_regs = (void *)&cdns->otg_v1_regs->cmd;
cdns->version = CDNS3_CONTROLLER_V1;
writel(1, &cdns->otg_v1_regs->simulate);
dev_info(cdns->dev, "DRD version v1 (ID: %08x, rev: %08x)\n",
readl(&cdns->otg_v1_regs->did),
readl(&cdns->otg_v1_regs->rid));
}
state = OTGSTS_STRAP(readl(&cdns->otg_regs->sts));
/* Update dr_mode according to STRAP configuration. */
cdns->dr_mode = USB_DR_MODE_OTG;
if (state == OTGSTS_STRAP_HOST) {
dev_dbg(cdns->dev, "Controller strapped to HOST\n");
cdns->dr_mode = USB_DR_MODE_HOST;
} else if (state == OTGSTS_STRAP_GADGET) {
dev_dbg(cdns->dev, "Controller strapped to PERIPHERAL\n");
cdns->dr_mode = USB_DR_MODE_PERIPHERAL;
}
ret = devm_request_threaded_irq(cdns->dev, cdns->otg_irq,
cdns3_drd_irq,
cdns3_drd_thread_irq,
IRQF_SHARED,
dev_name(cdns->dev), cdns);
if (ret) {
dev_err(cdns->dev, "couldn't get otg_irq\n");
return ret;
}
state = readl(&cdns->otg_regs->sts);
if (OTGSTS_OTG_NRDY(state) != 0) {
dev_err(cdns->dev, "Cadence USB3 OTG device not ready\n");
return -ENODEV;
}
return ret;
}
int cdns3_drd_exit(struct cdns3 *cdns)
{
cdns3_otg_disable_irq(cdns);
return 0;
}