// SPDX-License-Identifier: GPL-2.0+
/*
 * NetChip 2280 high/full speed USB device controller.
 * Unlike many such controllers, this one talks PCI.
 */

/*
 * Copyright (C) 2002 NetChip Technology, Inc. (http://www.netchip.com)
 * Copyright (C) 2003 David Brownell
 * Copyright (C) 2014 Ricardo Ribalda - Qtechnology/AS
 */

#include <linux/usb/net2280.h>
#include <linux/usb/usb338x.h>

/*-------------------------------------------------------------------------*/

#ifdef  __KERNEL__

/* indexed registers [11.10] are accessed indirectly
 * caller must own the device lock.
 */

static inline u32 get_idx_reg(struct net2280_regs __iomem *regs, u32 index)
{
        writel(index, &regs->idxaddr);
        /* NOTE:  synchs device/cpu memory views */
        return readl(&regs->idxdata);
}

static inline void
set_idx_reg(struct net2280_regs __iomem *regs, u32 index, u32 value)
{
        writel(index, &regs->idxaddr);
        writel(value, &regs->idxdata);
        /* posted, may not be visible yet */
}

#endif  /* __KERNEL__ */

#define PCI_VENDOR_ID_PLX_LEGACY 0x17cc

#define PLX_LEGACY              BIT(0)
#define PLX_2280                BIT(1)
#define PLX_SUPERSPEED          BIT(2)
#define PLX_PCIE                BIT(3)

#define REG_DIAG                0x0
#define     RETRY_COUNTER                                       16
#define     FORCE_PCI_SERR                                      11
#define     FORCE_PCI_INTERRUPT                                 10
#define     FORCE_USB_INTERRUPT                                 9
#define     FORCE_CPU_INTERRUPT                                 8
#define     ILLEGAL_BYTE_ENABLES                                5
#define     FAST_TIMES                                          4
#define     FORCE_RECEIVE_ERROR                                 2
#define     FORCE_TRANSMIT_CRC_ERROR                            0
#define REG_FRAME               0x02    /* from last sof */
#define REG_CHIPREV             0x03    /* in bcd */
#define REG_HS_NAK_RATE         0x0a    /* NAK per N uframes */

#define CHIPREV_1       0x0100
#define CHIPREV_1A      0x0110

/* DEFECT 7374 */
#define DEFECT_7374_NUMBEROF_MAX_WAIT_LOOPS         200
#define DEFECT_7374_PROCESSOR_WAIT_TIME             10

/* ep0 max packet size */
#define EP0_SS_MAX_PACKET_SIZE  0x200
#define EP0_HS_MAX_PACKET_SIZE  0x40
#ifdef  __KERNEL__

/*-------------------------------------------------------------------------*/

/* [8.3] for scatter/gather i/o
 * use struct net2280_dma_regs bitfields
 */
struct net2280_dma {
        __le32          dmacount;
        __le32          dmaaddr;                /* the buffer */
        __le32          dmadesc;                /* next dma descriptor */
        __le32          _reserved;
} __aligned(16);

/*-------------------------------------------------------------------------*/

/* DRIVER DATA STRUCTURES and UTILITIES */

struct net2280_ep {
        struct usb_ep                           ep;
        struct net2280_ep_regs __iomem *cfg;
        struct net2280_ep_regs                  __iomem *regs;
        struct net2280_dma_regs                 __iomem *dma;
        struct net2280_dma                      *dummy;
        dma_addr_t                              td_dma; /* of dummy */
        struct net2280                          *dev;
        unsigned long                           irqs;

        /* analogous to a host-side qh */
        struct list_head                        queue;
        const struct usb_endpoint_descriptor    *desc;
        unsigned                                num : 8,
                                                fifo_size : 12,
                                                in_fifo_validate : 1,
                                                out_overflow : 1,
                                                stopped : 1,
                                                wedged : 1,
                                                is_in : 1,
                                                is_iso : 1,
                                                responded : 1;
};

static inline void allow_status(struct net2280_ep *ep)
{
        /* ep0 only */
        writel(BIT(CLEAR_CONTROL_STATUS_PHASE_HANDSHAKE) |
                BIT(CLEAR_NAK_OUT_PACKETS) |
                BIT(CLEAR_NAK_OUT_PACKETS_MODE),
                &ep->regs->ep_rsp);
        ep->stopped = 1;
}

static inline void allow_status_338x(struct net2280_ep *ep)
{
        /*
         * Control Status Phase Handshake was set by the chip when the setup
         * packet arrived. While set, the chip automatically NAKs the host's
         * Status Phase tokens.
         */
        writel(BIT(CLEAR_CONTROL_STATUS_PHASE_HANDSHAKE), &ep->regs->ep_rsp);

        ep->stopped = 1;

        /* TD 9.9 Halt Endpoint test.  TD 9.22 set feature test. */
        ep->responded = 0;
}

struct net2280_request {
        struct usb_request              req;
        struct net2280_dma              *td;
        dma_addr_t                      td_dma;
        struct list_head                queue;
        unsigned                        mapped : 1,
                                        valid : 1;
};

struct net2280 {
        /* each pci device provides one gadget, several endpoints */
        struct usb_gadget               gadget;
        spinlock_t                      lock;
        struct net2280_ep               ep[9];
        struct usb_gadget_driver        *driver;
        unsigned                        enabled : 1,
                                        protocol_stall : 1,
                                        softconnect : 1,
                                        got_irq : 1,
                                        region:1,
                                        added:1,
                                        u1_enable:1,
                                        u2_enable:1,
                                        ltm_enable:1,
                                        wakeup_enable:1,
                                        addressed_state:1,
                                        async_callbacks:1,
                                        bug7734_patched:1;
        u16                             chiprev;
        int enhanced_mode;
        int n_ep;
        kernel_ulong_t                  quirks;


        /* pci state used to access those endpoints */
        struct pci_dev                  *pdev;
        struct net2280_regs             __iomem *regs;
        struct net2280_usb_regs         __iomem *usb;
        struct usb338x_usb_ext_regs     __iomem *usb_ext;
        struct net2280_pci_regs         __iomem *pci;
        struct net2280_dma_regs         __iomem *dma;
        struct net2280_dep_regs         __iomem *dep;
        struct net2280_ep_regs          __iomem *epregs;
        struct usb338x_ll_regs          __iomem *llregs;
        struct usb338x_pl_regs          __iomem *plregs;

        struct dma_pool                 *requests;
        /* statistics...*/
};

static inline void set_halt(struct net2280_ep *ep)
{
        /* ep0 and bulk/intr endpoints */
        writel(BIT(CLEAR_CONTROL_STATUS_PHASE_HANDSHAKE) |
                /* set NAK_OUT for erratum 0114 */
                ((ep->dev->chiprev == CHIPREV_1) << SET_NAK_OUT_PACKETS) |
                BIT(SET_ENDPOINT_HALT),
                &ep->regs->ep_rsp);
}

static inline void clear_halt(struct net2280_ep *ep)
{
        /* ep0 and bulk/intr endpoints */
        writel(BIT(CLEAR_ENDPOINT_HALT) |
                BIT(CLEAR_ENDPOINT_TOGGLE) |
                    /*
                     * unless the gadget driver left a short packet in the
                     * fifo, this reverses the erratum 0114 workaround.
                     */
                ((ep->dev->chiprev == CHIPREV_1) << CLEAR_NAK_OUT_PACKETS),
                &ep->regs->ep_rsp);
}

/*
 * FSM value for Defect 7374 (U1U2 Test) is managed in
 * chip's SCRATCH register:
 */
#define DEFECT7374_FSM_FIELD    28

/* Waiting for Control Read:
 *  - A transition to this state indicates a fresh USB connection,
 *    before the first Setup Packet. The connection speed is not
 *    known. Firmware is waiting for the first Control Read.
 *  - Starting state: This state can be thought of as the FSM's typical
 *    starting state.
 *  - Tip: Upon the first SS Control Read the FSM never
 *    returns to this state.
 */
#define DEFECT7374_FSM_WAITING_FOR_CONTROL_READ BIT(DEFECT7374_FSM_FIELD)

/* Non-SS Control Read:
 *  - A transition to this state indicates detection of the first HS
 *    or FS Control Read.
 *  - Tip: Upon the first SS Control Read the FSM never
 *    returns to this state.
 */
#define DEFECT7374_FSM_NON_SS_CONTROL_READ (2 << DEFECT7374_FSM_FIELD)

/* SS Control Read:
 *  - A transition to this state indicates detection of the
 *    first SS Control Read.
 *  - This state indicates workaround completion. Workarounds no longer
 *    need to be applied (as long as the chip remains powered up).
 *  - Tip: Once in this state the FSM state does not change (until
 *    the chip's power is lost and restored).
 *  - This can be thought of as the final state of the FSM;
 *    the FSM 'locks-up' in this state until the chip loses power.
 */
#define DEFECT7374_FSM_SS_CONTROL_READ (3 << DEFECT7374_FSM_FIELD)

#ifdef USE_RDK_LEDS

static inline void net2280_led_init(struct net2280 *dev)
{
        /* LED3 (green) is on during USB activity. note erratum 0113. */
        writel(BIT(GPIO3_LED_SELECT) |
                BIT(GPIO3_OUTPUT_ENABLE) |
                BIT(GPIO2_OUTPUT_ENABLE) |
                BIT(GPIO1_OUTPUT_ENABLE) |
                BIT(GPIO0_OUTPUT_ENABLE),
                &dev->regs->gpioctl);
}

/* indicate speed with bi-color LED 0/1 */
static inline
void net2280_led_speed(struct net2280 *dev, enum usb_device_speed speed)
{
        u32     val = readl(&dev->regs->gpioctl);
        switch (speed) {
        case USB_SPEED_SUPER:           /* green + red */
                val |= BIT(GPIO0_DATA) | BIT(GPIO1_DATA);
                break;
        case USB_SPEED_HIGH:            /* green */
                val &= ~BIT(GPIO0_DATA);
                val |= BIT(GPIO1_DATA);
                break;
        case USB_SPEED_FULL:            /* red */
                val &= ~BIT(GPIO1_DATA);
                val |= BIT(GPIO0_DATA);
                break;
        default:                        /* (off/black) */
                val &= ~(BIT(GPIO1_DATA) | BIT(GPIO0_DATA));
                break;
        }
        writel(val, &dev->regs->gpioctl);
}

/* indicate power with LED 2 */
static inline void net2280_led_active(struct net2280 *dev, int is_active)
{
        u32     val = readl(&dev->regs->gpioctl);

        /* FIXME this LED never seems to turn on.*/
        if (is_active)
                val |= GPIO2_DATA;
        else
                val &= ~GPIO2_DATA;
        writel(val, &dev->regs->gpioctl);
}

static inline void net2280_led_shutdown(struct net2280 *dev)
{
        /* turn off all four GPIO*_DATA bits */
        writel(readl(&dev->regs->gpioctl) & ~0x0f,
                        &dev->regs->gpioctl);
}

#else

#define net2280_led_init(dev)           do { } while (0)
#define net2280_led_speed(dev, speed)   do { } while (0)
#define net2280_led_shutdown(dev)       do { } while (0)

#endif

/*-------------------------------------------------------------------------*/

#define ep_dbg(ndev, fmt, args...) \
        dev_dbg((&((ndev)->pdev->dev)), fmt, ##args)

#define ep_vdbg(ndev, fmt, args...) \
        dev_vdbg((&((ndev)->pdev->dev)), fmt, ##args)

#define ep_info(ndev, fmt, args...) \
        dev_info((&((ndev)->pdev->dev)), fmt, ##args)

#define ep_warn(ndev, fmt, args...) \
        dev_warn((&((ndev)->pdev->dev)), fmt, ##args)

#define ep_err(ndev, fmt, args...) \
        dev_err((&((ndev)->pdev->dev)), fmt, ##args)

/*-------------------------------------------------------------------------*/

static inline void set_fifo_bytecount(struct net2280_ep *ep, unsigned count)
{
        if (ep->dev->pdev->vendor == 0x17cc)
                writeb(count, 2 + (u8 __iomem *) &ep->regs->ep_cfg);
        else{
                u32 tmp = readl(&ep->cfg->ep_cfg) &
                                        (~(0x07 << EP_FIFO_BYTE_COUNT));
                writel(tmp | (count << EP_FIFO_BYTE_COUNT), &ep->cfg->ep_cfg);
        }
}

static inline void start_out_naking(struct net2280_ep *ep)
{
        /* NOTE:  hardware races lurk here, and PING protocol issues */
        writel(BIT(SET_NAK_OUT_PACKETS), &ep->regs->ep_rsp);
        /* synch with device */
        readl(&ep->regs->ep_rsp);
}

static inline void stop_out_naking(struct net2280_ep *ep)
{
        u32     tmp;

        tmp = readl(&ep->regs->ep_stat);
        if ((tmp & BIT(NAK_OUT_PACKETS)) != 0)
                writel(BIT(CLEAR_NAK_OUT_PACKETS), &ep->regs->ep_rsp);
}


static inline void set_max_speed(struct net2280_ep *ep, u32 max)
{
        u32 reg;
        static const u32 ep_enhanced[9] = { 0x10, 0x60, 0x30, 0x80,
                                          0x50, 0x20, 0x70, 0x40, 0x90 };

        if (ep->dev->enhanced_mode) {
                reg = ep_enhanced[ep->num];
                switch (ep->dev->gadget.speed) {
                case USB_SPEED_SUPER:
                        reg += 2;
                        break;
                case USB_SPEED_FULL:
                        reg += 1;
                        break;
                case USB_SPEED_HIGH:
                default:
                        break;
                }
        } else {
                reg = (ep->num + 1) * 0x10;
                if (ep->dev->gadget.speed != USB_SPEED_HIGH)
                        reg += 1;
        }

        set_idx_reg(ep->dev->regs, reg, max);
}

#endif  /* __KERNEL__ */