Staging
v0.6.0
v0.6.0
https://github.com/torvalds/linux
Tip revision: 2dde18cd1d8fac735875f2e4987f11817cc0bc2c authored by Linus Torvalds on 27 August 2023, 21:49:51 UTC
Linux 6.5
Linux 6.5
Tip revision: 2dde18c
8250_pci1xxxx.c
// SPDX-License-Identifier: GPL-2.0
/*
* Probe module for 8250/16550-type MCHP PCI serial ports.
*
* Based on drivers/tty/serial/8250/8250_pci.c,
*
* Copyright (C) 2022 Microchip Technology Inc., All Rights Reserved.
*/
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/serial_core.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/units.h>
#include <linux/tty.h>
#include <asm/byteorder.h>
#include "8250.h"
#include "8250_pcilib.h"
#define PCI_DEVICE_ID_EFAR_PCI12000 0xa002
#define PCI_DEVICE_ID_EFAR_PCI11010 0xa012
#define PCI_DEVICE_ID_EFAR_PCI11101 0xa022
#define PCI_DEVICE_ID_EFAR_PCI11400 0xa032
#define PCI_DEVICE_ID_EFAR_PCI11414 0xa042
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_4p 0x0001
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p012 0x0002
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p013 0x0003
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p023 0x0004
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p123 0x0005
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p01 0x0006
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p02 0x0007
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p03 0x0008
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p12 0x0009
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p13 0x000a
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p23 0x000b
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p0 0x000c
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p1 0x000d
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p2 0x000e
#define PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p3 0x000f
#define PCI_SUBDEVICE_ID_EFAR_PCI12000 PCI_DEVICE_ID_EFAR_PCI12000
#define PCI_SUBDEVICE_ID_EFAR_PCI11010 PCI_DEVICE_ID_EFAR_PCI11010
#define PCI_SUBDEVICE_ID_EFAR_PCI11101 PCI_DEVICE_ID_EFAR_PCI11101
#define PCI_SUBDEVICE_ID_EFAR_PCI11400 PCI_DEVICE_ID_EFAR_PCI11400
#define PCI_SUBDEVICE_ID_EFAR_PCI11414 PCI_DEVICE_ID_EFAR_PCI11414
#define UART_ACTV_REG 0x11
#define UART_BLOCK_SET_ACTIVE BIT(0)
#define UART_PCI_CTRL_REG 0x80
#define UART_PCI_CTRL_SET_MULTIPLE_MSI BIT(4)
#define UART_PCI_CTRL_D3_CLK_ENABLE BIT(0)
#define ADCL_CFG_REG 0x40
#define ADCL_CFG_POL_SEL BIT(2)
#define ADCL_CFG_PIN_SEL BIT(1)
#define ADCL_CFG_EN BIT(0)
#define UART_BIT_SAMPLE_CNT 16
#define BAUD_CLOCK_DIV_INT_MSK GENMASK(31, 8)
#define ADCL_CFG_RTS_DELAY_MASK GENMASK(11, 8)
#define UART_CLOCK_DEFAULT (62500 * HZ_PER_KHZ)
#define UART_WAKE_REG 0x8C
#define UART_WAKE_MASK_REG 0x90
#define UART_WAKE_N_PIN BIT(2)
#define UART_WAKE_NCTS BIT(1)
#define UART_WAKE_INT BIT(0)
#define UART_WAKE_SRCS \
(UART_WAKE_N_PIN | UART_WAKE_NCTS | UART_WAKE_INT)
#define UART_BAUD_CLK_DIVISOR_REG 0x54
#define UART_RESET_REG 0x94
#define UART_RESET_D3_RESET_DISABLE BIT(16)
#define MAX_PORTS 4
#define PORT_OFFSET 0x100
static const int logical_to_physical_port_idx[][MAX_PORTS] = {
{0, 1, 2, 3}, /* PCI12000, PCI11010, PCI11101, PCI11400, PCI11414 */
{0, 1, 2, 3}, /* PCI4p */
{0, 1, 2, -1}, /* PCI3p012 */
{0, 1, 3, -1}, /* PCI3p013 */
{0, 2, 3, -1}, /* PCI3p023 */
{1, 2, 3, -1}, /* PCI3p123 */
{0, 1, -1, -1}, /* PCI2p01 */
{0, 2, -1, -1}, /* PCI2p02 */
{0, 3, -1, -1}, /* PCI2p03 */
{1, 2, -1, -1}, /* PCI2p12 */
{1, 3, -1, -1}, /* PCI2p13 */
{2, 3, -1, -1}, /* PCI2p23 */
{0, -1, -1, -1}, /* PCI1p0 */
{1, -1, -1, -1}, /* PCI1p1 */
{2, -1, -1, -1}, /* PCI1p2 */
{3, -1, -1, -1}, /* PCI1p3 */
};
struct pci1xxxx_8250 {
unsigned int nr;
void __iomem *membase;
int line[];
};
static int pci1xxxx_get_num_ports(struct pci_dev *dev)
{
switch (dev->subsystem_device) {
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p0:
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p1:
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p2:
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p3:
case PCI_SUBDEVICE_ID_EFAR_PCI12000:
case PCI_SUBDEVICE_ID_EFAR_PCI11010:
case PCI_SUBDEVICE_ID_EFAR_PCI11101:
case PCI_SUBDEVICE_ID_EFAR_PCI11400:
default:
return 1;
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p01:
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p02:
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p03:
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p12:
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p13:
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p23:
return 2;
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p012:
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p123:
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p013:
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p023:
return 3;
case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_4p:
case PCI_SUBDEVICE_ID_EFAR_PCI11414:
return 4;
}
}
static unsigned int pci1xxxx_get_divisor(struct uart_port *port,
unsigned int baud, unsigned int *frac)
{
unsigned int quot;
/*
* Calculate baud rate sampling period in nanoseconds.
* Fractional part x denotes x/255 parts of a nanosecond.
*/
quot = NSEC_PER_SEC / (baud * UART_BIT_SAMPLE_CNT);
*frac = (NSEC_PER_SEC - quot * baud * UART_BIT_SAMPLE_CNT) *
255 / UART_BIT_SAMPLE_CNT / baud;
return quot;
}
static void pci1xxxx_set_divisor(struct uart_port *port, unsigned int baud,
unsigned int quot, unsigned int frac)
{
writel(FIELD_PREP(BAUD_CLOCK_DIV_INT_MSK, quot) | frac,
port->membase + UART_BAUD_CLK_DIVISOR_REG);
}
static int pci1xxxx_rs485_config(struct uart_port *port,
struct ktermios *termios,
struct serial_rs485 *rs485)
{
u32 delay_in_baud_periods;
u32 baud_period_in_ns;
u32 mode_cfg = 0;
u32 clock_div;
/*
* pci1xxxx's uart hardware supports only RTS delay after
* Tx and in units of bit times to a maximum of 15
*/
if (rs485->flags & SER_RS485_ENABLED) {
mode_cfg = ADCL_CFG_EN | ADCL_CFG_PIN_SEL;
if (!(rs485->flags & SER_RS485_RTS_ON_SEND))
mode_cfg |= ADCL_CFG_POL_SEL;
if (rs485->delay_rts_after_send) {
clock_div = readl(port->membase + UART_BAUD_CLK_DIVISOR_REG);
baud_period_in_ns =
FIELD_GET(BAUD_CLOCK_DIV_INT_MSK, clock_div) *
UART_BIT_SAMPLE_CNT;
delay_in_baud_periods =
rs485->delay_rts_after_send * NSEC_PER_MSEC /
baud_period_in_ns;
delay_in_baud_periods =
min_t(u32, delay_in_baud_periods,
FIELD_MAX(ADCL_CFG_RTS_DELAY_MASK));
mode_cfg |= FIELD_PREP(ADCL_CFG_RTS_DELAY_MASK,
delay_in_baud_periods);
rs485->delay_rts_after_send =
baud_period_in_ns * delay_in_baud_periods /
NSEC_PER_MSEC;
}
}
writel(mode_cfg, port->membase + ADCL_CFG_REG);
return 0;
}
static const struct serial_rs485 pci1xxxx_rs485_supported = {
.flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
SER_RS485_RTS_AFTER_SEND,
.delay_rts_after_send = 1,
/* Delay RTS before send is not supported */
};
static bool pci1xxxx_port_suspend(int line)
{
struct uart_8250_port *up = serial8250_get_port(line);
struct uart_port *port = &up->port;
struct tty_port *tport = &port->state->port;
unsigned long flags;
bool ret = false;
u8 wakeup_mask;
mutex_lock(&tport->mutex);
if (port->suspended == 0 && port->dev) {
wakeup_mask = readb(up->port.membase + UART_WAKE_MASK_REG);
spin_lock_irqsave(&port->lock, flags);
port->mctrl &= ~TIOCM_OUT2;
port->ops->set_mctrl(port, port->mctrl);
spin_unlock_irqrestore(&port->lock, flags);
ret = (wakeup_mask & UART_WAKE_SRCS) != UART_WAKE_SRCS;
}
writeb(UART_WAKE_SRCS, port->membase + UART_WAKE_REG);
mutex_unlock(&tport->mutex);
return ret;
}
static void pci1xxxx_port_resume(int line)
{
struct uart_8250_port *up = serial8250_get_port(line);
struct uart_port *port = &up->port;
struct tty_port *tport = &port->state->port;
unsigned long flags;
mutex_lock(&tport->mutex);
writeb(UART_BLOCK_SET_ACTIVE, port->membase + UART_ACTV_REG);
writeb(UART_WAKE_SRCS, port->membase + UART_WAKE_REG);
if (port->suspended == 0) {
spin_lock_irqsave(&port->lock, flags);
port->mctrl |= TIOCM_OUT2;
port->ops->set_mctrl(port, port->mctrl);
spin_unlock_irqrestore(&port->lock, flags);
}
mutex_unlock(&tport->mutex);
}
static int pci1xxxx_suspend(struct device *dev)
{
struct pci1xxxx_8250 *priv = dev_get_drvdata(dev);
struct pci_dev *pcidev = to_pci_dev(dev);
bool wakeup = false;
unsigned int data;
void __iomem *p;
int i;
for (i = 0; i < priv->nr; i++) {
if (priv->line[i] >= 0) {
serial8250_suspend_port(priv->line[i]);
wakeup |= pci1xxxx_port_suspend(priv->line[i]);
}
}
p = pci_ioremap_bar(pcidev, 0);
if (!p) {
dev_err(dev, "remapping of bar 0 memory failed");
return -ENOMEM;
}
data = readl(p + UART_RESET_REG);
writel(data | UART_RESET_D3_RESET_DISABLE, p + UART_RESET_REG);
if (wakeup)
writeb(UART_PCI_CTRL_D3_CLK_ENABLE, p + UART_PCI_CTRL_REG);
iounmap(p);
device_set_wakeup_enable(dev, true);
pci_wake_from_d3(pcidev, true);
return 0;
}
static int pci1xxxx_resume(struct device *dev)
{
struct pci1xxxx_8250 *priv = dev_get_drvdata(dev);
struct pci_dev *pcidev = to_pci_dev(dev);
unsigned int data;
void __iomem *p;
int i;
p = pci_ioremap_bar(pcidev, 0);
if (!p) {
dev_err(dev, "remapping of bar 0 memory failed");
return -ENOMEM;
}
data = readl(p + UART_RESET_REG);
writel(data & ~UART_RESET_D3_RESET_DISABLE, p + UART_RESET_REG);
iounmap(p);
for (i = 0; i < priv->nr; i++) {
if (priv->line[i] >= 0) {
pci1xxxx_port_resume(priv->line[i]);
serial8250_resume_port(priv->line[i]);
}
}
return 0;
}
static int pci1xxxx_setup(struct pci_dev *pdev,
struct uart_8250_port *port, int port_idx)
{
int ret;
port->port.flags |= UPF_FIXED_TYPE | UPF_SKIP_TEST;
port->port.type = PORT_MCHP16550A;
port->port.set_termios = serial8250_do_set_termios;
port->port.get_divisor = pci1xxxx_get_divisor;
port->port.set_divisor = pci1xxxx_set_divisor;
port->port.rs485_config = pci1xxxx_rs485_config;
port->port.rs485_supported = pci1xxxx_rs485_supported;
ret = serial8250_pci_setup_port(pdev, port, 0, PORT_OFFSET * port_idx, 0);
if (ret < 0)
return ret;
writeb(UART_BLOCK_SET_ACTIVE, port->port.membase + UART_ACTV_REG);
writeb(UART_WAKE_SRCS, port->port.membase + UART_WAKE_REG);
writeb(UART_WAKE_N_PIN, port->port.membase + UART_WAKE_MASK_REG);
return 0;
}
static unsigned int pci1xxxx_get_max_port(int subsys_dev)
{
unsigned int i = MAX_PORTS;
if (subsys_dev < ARRAY_SIZE(logical_to_physical_port_idx))
while (i--) {
if (logical_to_physical_port_idx[subsys_dev][i] != -1)
return logical_to_physical_port_idx[subsys_dev][i] + 1;
}
if (subsys_dev == PCI_SUBDEVICE_ID_EFAR_PCI11414)
return 4;
return 1;
}
static int pci1xxxx_logical_to_physical_port_translate(int subsys_dev, int port)
{
if (subsys_dev < ARRAY_SIZE(logical_to_physical_port_idx))
return logical_to_physical_port_idx[subsys_dev][port];
return logical_to_physical_port_idx[0][port];
}
static int pci1xxxx_serial_probe(struct pci_dev *pdev,
const struct pci_device_id *id)
{
struct device *dev = &pdev->dev;
struct pci1xxxx_8250 *priv;
struct uart_8250_port uart;
unsigned int max_vec_reqd;
unsigned int nr_ports, i;
int num_vectors;
int subsys_dev;
int port_idx;
int rc;
rc = pcim_enable_device(pdev);
if (rc)
return rc;
nr_ports = pci1xxxx_get_num_ports(pdev);
priv = devm_kzalloc(dev, struct_size(priv, line, nr_ports), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->membase = pci_ioremap_bar(pdev, 0);
if (!priv->membase)
return -ENOMEM;
pci_set_master(pdev);
priv->nr = nr_ports;
subsys_dev = pdev->subsystem_device;
max_vec_reqd = pci1xxxx_get_max_port(subsys_dev);
num_vectors = pci_alloc_irq_vectors(pdev, 1, max_vec_reqd, PCI_IRQ_ALL_TYPES);
if (num_vectors < 0) {
pci_iounmap(pdev, priv->membase);
return num_vectors;
}
memset(&uart, 0, sizeof(uart));
uart.port.flags = UPF_SHARE_IRQ | UPF_FIXED_PORT;
uart.port.uartclk = UART_CLOCK_DEFAULT;
uart.port.dev = dev;
if (num_vectors == max_vec_reqd)
writeb(UART_PCI_CTRL_SET_MULTIPLE_MSI, priv->membase + UART_PCI_CTRL_REG);
for (i = 0; i < nr_ports; i++) {
priv->line[i] = -ENODEV;
port_idx = pci1xxxx_logical_to_physical_port_translate(subsys_dev, i);
if (num_vectors == max_vec_reqd)
uart.port.irq = pci_irq_vector(pdev, port_idx);
else
uart.port.irq = pci_irq_vector(pdev, 0);
rc = pci1xxxx_setup(pdev, &uart, port_idx);
if (rc) {
dev_warn(dev, "Failed to setup port %u\n", i);
continue;
}
priv->line[i] = serial8250_register_8250_port(&uart);
if (priv->line[i] < 0) {
dev_warn(dev,
"Couldn't register serial port %lx, irq %d, type %d, error %d\n",
uart.port.iobase, uart.port.irq, uart.port.iotype,
priv->line[i]);
}
}
pci_set_drvdata(pdev, priv);
return 0;
}
static void pci1xxxx_serial_remove(struct pci_dev *dev)
{
struct pci1xxxx_8250 *priv = pci_get_drvdata(dev);
unsigned int i;
for (i = 0; i < priv->nr; i++) {
if (priv->line[i] >= 0)
serial8250_unregister_port(priv->line[i]);
}
pci_free_irq_vectors(dev);
pci_iounmap(dev, priv->membase);
}
static DEFINE_SIMPLE_DEV_PM_OPS(pci1xxxx_pm_ops, pci1xxxx_suspend, pci1xxxx_resume);
static const struct pci_device_id pci1xxxx_pci_tbl[] = {
{ PCI_VDEVICE(EFAR, PCI_DEVICE_ID_EFAR_PCI11010) },
{ PCI_VDEVICE(EFAR, PCI_DEVICE_ID_EFAR_PCI11101) },
{ PCI_VDEVICE(EFAR, PCI_DEVICE_ID_EFAR_PCI11400) },
{ PCI_VDEVICE(EFAR, PCI_DEVICE_ID_EFAR_PCI11414) },
{ PCI_VDEVICE(EFAR, PCI_DEVICE_ID_EFAR_PCI12000) },
{}
};
MODULE_DEVICE_TABLE(pci, pci1xxxx_pci_tbl);
static struct pci_driver pci1xxxx_pci_driver = {
.name = "pci1xxxx serial",
.probe = pci1xxxx_serial_probe,
.remove = pci1xxxx_serial_remove,
.driver = {
.pm = pm_sleep_ptr(&pci1xxxx_pm_ops),
},
.id_table = pci1xxxx_pci_tbl,
};
module_pci_driver(pci1xxxx_pci_driver);
static_assert((ARRAY_SIZE(logical_to_physical_port_idx) == PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p3 + 1));
MODULE_IMPORT_NS(SERIAL_8250_PCI);
MODULE_DESCRIPTION("Microchip Technology Inc. PCIe to UART module");
MODULE_AUTHOR("Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>");
MODULE_AUTHOR("Tharun Kumar P <tharunkumar.pasumarthi@microchip.com>");
MODULE_LICENSE("GPL");