serial: 8250_pci: Split out Pericom driver

Pericom along with Acces I/O support consumes a lot of LOCs in 8250_pci.c.
For the sake of easier maintenance, split it to a separate driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20211122133512.8947-2-andriy.shevchenko@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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) {
+			int lcr = serial_port_in(port, UART_LCR);
+
+			serial_port_out(port, UART_LCR, lcr | 0x80);
+			serial_port_out(port, UART_DLL, divisor & 0xff);
+			serial_port_out(port, UART_DLM, (divisor >> 8) & 0xff);
+			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");

drivers/tty/serial/8250/Kconfig

@@ -498,6 +498,14 @@ config SERIAL_8250_MID
 	  present on the UART found on Intel Medfield SOC and various other
 	  Intel platforms.
 
+config SERIAL_8250_PERICOM
+	tristate "Support for Pericom and Acces I/O serial ports"
+	default SERIAL_8250
+	depends on SERIAL_8250 && PCI
+	help
+	  Selecting this option will enable handling of the extra features
+	  present on the Pericom and Acces I/O UARTs.
+
 config SERIAL_8250_PXA
 	tristate "PXA serial port support"
 	depends on SERIAL_8250

drivers/tty/serial/8250/Makefile

@@ -36,6 +36,7 @@ obj-$(CONFIG_SERIAL_8250_UNIPHIER)	+= 8250_uniphier.o
 obj-$(CONFIG_SERIAL_8250_INGENIC)	+= 8250_ingenic.o
 obj-$(CONFIG_SERIAL_8250_LPSS)		+= 8250_lpss.o
 obj-$(CONFIG_SERIAL_8250_MID)		+= 8250_mid.o
+obj-$(CONFIG_SERIAL_8250_PERICOM)	+= 8250_pericom.o
 obj-$(CONFIG_SERIAL_8250_PXA)		+= 8250_pxa.o
 obj-$(CONFIG_SERIAL_8250_TEGRA)		+= 8250_tegra.o
 obj-$(CONFIG_SERIAL_8250_BCM7271)	+= 8250_bcm7271.o