root/drivers/tty/serial/8250/8250_pericom.c
// SPDX-License-Identifier: GPL-2.0
/* Driver for Pericom UART */

#include <linux/bits.h>
#include <linux/module.h>
#include <linux/overflow.h>
#include <linux/pci.h>

#include "8250.h"

#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_2SDB    0x1051
#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_2S     0x1053
#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM422_4    0x105a
#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM485_4    0x105b
#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SDB    0x105c
#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_4S     0x105e
#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM422_8    0x106a
#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM485_8    0x106b
#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_2DB  0x1091
#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM232_2   0x1093
#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_4    0x1098
#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_4DB  0x1099
#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM232_4   0x109b
#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_8    0x10a9
#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_2SMDB   0x10d1
#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_2SM    0x10d3
#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SM     0x10d9
#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SMDB   0x10da
#define PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_4SM    0x10dc
#define PCI_DEVICE_ID_ACCESSIO_PCIE_COM_8SM     0x10e9
#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_1   0x1108
#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM422_2   0x1110
#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_2   0x1111
#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM422_4   0x1118
#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_4   0x1119
#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_2S      0x1152
#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_4S      0x115a
#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM232_2    0x1190
#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM232_2   0x1191
#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM232_4    0x1198
#define PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM232_4   0x1199
#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_2SM     0x11d0
#define PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_4SM     0x11d8

struct pericom8250 {
        void __iomem *virt;
        unsigned int nr;
        int line[];
};

static void pericom_do_set_divisor(struct uart_port *port, unsigned int baud,
                                   unsigned int quot, unsigned int quot_frac)
{
        int scr;

        for (scr = 16; scr > 4; scr--) {
                unsigned int maxrate = port->uartclk / scr;
                unsigned int divisor = max(maxrate / baud, 1U);
                int delta = maxrate / divisor - baud;

                if (baud > maxrate + baud / 50)
                        continue;

                if (delta > baud / 50)
                        divisor++;

                if (divisor > 0xffff)
                        continue;

                /* Update delta due to possible divisor change */
                delta = maxrate / divisor - baud;
                if (abs(delta) < baud / 50) {
                        struct uart_8250_port *up = up_to_u8250p(port);
                        int lcr = serial_port_in(port, UART_LCR);

                        serial_port_out(port, UART_LCR, lcr | UART_LCR_DLAB);
                        serial_dl_write(up, divisor);
                        serial_port_out(port, 2, 16 - scr);
                        serial_port_out(port, UART_LCR, lcr);
                        return;
                }
        }
}

static int pericom8250_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
        unsigned int nr, i, bar = 0, maxnr;
        struct pericom8250 *pericom;
        struct uart_8250_port uart;
        int ret;

        ret = pcim_enable_device(pdev);
        if (ret)
                return ret;

        maxnr = pci_resource_len(pdev, bar) >> 3;

        if (pdev->vendor == PCI_VENDOR_ID_PERICOM)
                nr = pdev->device & 0x0f;
        else if (pdev->vendor == PCI_VENDOR_ID_ACCESSIO)
                nr = BIT(((pdev->device & 0x38) >> 3) - 1);
        else
                nr = 1;

        pericom = devm_kzalloc(&pdev->dev, struct_size(pericom, line, nr), GFP_KERNEL);
        if (!pericom)
                return -ENOMEM;

        pericom->virt = pcim_iomap(pdev, bar, 0);
        if (!pericom->virt)
                return -ENOMEM;

        memset(&uart, 0, sizeof(uart));

        uart.port.dev = &pdev->dev;
        uart.port.irq = pdev->irq;
        uart.port.private_data = pericom;
        uart.port.iotype = UPIO_PORT;
        uart.port.uartclk = 921600 * 16;
        uart.port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF | UPF_SHARE_IRQ;
        uart.port.set_divisor = pericom_do_set_divisor;
        for (i = 0; i < nr && i < maxnr; i++) {
                unsigned int offset = (i == 3 && nr == 4) ? 0x38 : i * 0x8;

                uart.port.iobase = pci_resource_start(pdev, bar) + offset;

                dev_dbg(&pdev->dev, "Setup PCI port: port %lx, irq %d, type %d\n",
                        uart.port.iobase, uart.port.irq, uart.port.iotype);

                pericom->line[i] = serial8250_register_8250_port(&uart);
                if (pericom->line[i] < 0) {
                        dev_err(&pdev->dev,
                                "Couldn't register serial port %lx, irq %d, type %d, error %d\n",
                                uart.port.iobase, uart.port.irq,
                                uart.port.iotype, pericom->line[i]);
                        break;
                }
        }
        pericom->nr = i;

        pci_set_drvdata(pdev, pericom);
        return 0;
}

static void pericom8250_remove(struct pci_dev *pdev)
{
        struct pericom8250 *pericom = pci_get_drvdata(pdev);
        unsigned int i;

        for (i = 0; i < pericom->nr; i++)
                serial8250_unregister_port(pericom->line[i]);
}

static const struct pci_device_id pericom8250_pci_ids[] = {
        /*
         * Pericom PI7C9X795[1248] Uno/Dual/Quad/Octal UART
         * (Only 7954 has an offset jump for port 4)
         */
        { PCI_VDEVICE(PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7951) },
        { PCI_VDEVICE(PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7952) },
        { PCI_VDEVICE(PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7954) },
        { PCI_VDEVICE(PERICOM, PCI_DEVICE_ID_PERICOM_PI7C9X7958) },

        /*
         * ACCES I/O Products quad
         * (Only 7954 has an offset jump for port 4)
         */
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_2SDB) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_2S) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM422_4) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM485_4) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SDB) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_4S) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM422_8) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM485_8) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_2DB) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM232_2) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_4) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_4DB) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM232_4) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM232_8) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_2SMDB) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_2SM) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SM) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_4SMDB) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_COM_4SM) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_COM_8SM) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_1) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM422_2) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_2) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM422_4) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM485_4) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_2S) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_4S) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM232_2) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM232_2) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM232_4) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_MPCIE_ICM232_4) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_2SM) },
        { PCI_VDEVICE(ACCESSIO, PCI_DEVICE_ID_ACCESSIO_PCIE_ICM_4SM) },
        { }
};
MODULE_DEVICE_TABLE(pci, pericom8250_pci_ids);

static struct pci_driver pericom8250_pci_driver = {
        .name           = "8250_pericom",
        .id_table       = pericom8250_pci_ids,
        .probe          = pericom8250_probe,
        .remove         = pericom8250_remove,
};
module_pci_driver(pericom8250_pci_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Pericom UART driver");