2022-11-07 13:05:49

by Kumaravel Thiagarajan

[permalink] [raw]
Subject: [PATCH v3 tty-next 1/3] 8250: microchip: pci1xxxx: Add driver for quad-uart support.

pci1xxxx is a PCIe switch with a multi-function endpoint on one of
its downstream ports. Quad-uart is one of the functions in the
multi-function endpoint. This driver loads for the quad-uart and
enumerates single or multiple instances of uart based on the PCIe
subsystem device ID.

Signed-off-by: Kumaravel Thiagarajan <[email protected]>
Signed-off-by: Tharun Kumar P <[email protected]>
---
Changes in v3:
- Used NSEC_PER_SEC, HZ_PER_MHZ, FIELD_PREP, FIELD_GET MACROs wherever
necessary
- Handled failure case of serial8250_register_8250_port properly
- Moved pci_setup_port to 8250_pcilib.c

Changes in v2:
- Use only the 62.5 MHz for baud clock.
- Define custom implementation for get_divisor and set_divisor.
- Use BOTHER instead of UPF_SPD_CUST for non standard baud rates
(untested).
- Correct indentation in clock divisor computation.
- Remove unnecessary call to pci_save_state in probe function.
- Fix null pointer dereference in probe function.
- Move pci1xxxx_rs485_config to a separate patch.
- Depends on SERIAL_8250_PCI & default to SERIAL_8250.
- Change PORT_MCHP16550A to 100 from 124.
---
MAINTAINERS | 7 +
drivers/tty/serial/8250/8250_pci.c | 24 +-
drivers/tty/serial/8250/8250_pci1xxxx.c | 370 ++++++++++++++++++++++++
drivers/tty/serial/8250/8250_pcilib.c | 31 ++
drivers/tty/serial/8250/8250_pcilib.h | 5 +
drivers/tty/serial/8250/8250_port.c | 8 +
drivers/tty/serial/8250/Kconfig | 15 +
drivers/tty/serial/8250/Makefile | 2 +
include/uapi/linux/serial_core.h | 3 +
9 files changed, 443 insertions(+), 22 deletions(-)
create mode 100644 drivers/tty/serial/8250/8250_pci1xxxx.c
create mode 100644 drivers/tty/serial/8250/8250_pcilib.c
create mode 100644 drivers/tty/serial/8250/8250_pcilib.h

diff --git a/MAINTAINERS b/MAINTAINERS
index d30f26e07cd3..aa98deaba249 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13434,6 +13434,13 @@ F: Documentation/devicetree/bindings/nvmem/microchip,sama7g5-otpc.yaml
F: drivers/nvmem/microchip-otpc.c
F: include/dt-bindings/nvmem/microchip,sama7g5-otpc.h

+MICROCHIP PCIe UART DRIVER
+M: Kumaravel Thiagarajan <[email protected]>
+M: Tharun Kumar P <[email protected]>
+L: [email protected]
+S: Maintained
+F: drivers/tty/serial/8250/8250_pci1xxxx.c
+
MICROCHIP PWM DRIVER
M: Claudiu Beznea <[email protected]>
L: [email protected] (moderated for non-subscribers)
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 6f66dc2ebacc..e7023f1b9b2c 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -24,6 +24,7 @@
#include <asm/io.h>

#include "8250.h"
+#include "8250_pcilib.h"

/*
* init function returns:
@@ -89,28 +90,7 @@ static int
setup_port(struct serial_private *priv, struct uart_8250_port *port,
u8 bar, unsigned int offset, int regshift)
{
- struct pci_dev *dev = priv->dev;
-
- if (bar >= PCI_STD_NUM_BARS)
- return -EINVAL;
-
- if (pci_resource_flags(dev, bar) & IORESOURCE_MEM) {
- if (!pcim_iomap(dev, bar, 0) && !pcim_iomap_table(dev))
- return -ENOMEM;
-
- port->port.iotype = UPIO_MEM;
- port->port.iobase = 0;
- port->port.mapbase = pci_resource_start(dev, bar) + offset;
- port->port.membase = pcim_iomap_table(dev)[bar] + offset;
- port->port.regshift = regshift;
- } else {
- port->port.iotype = UPIO_PORT;
- port->port.iobase = pci_resource_start(dev, bar) + offset;
- port->port.mapbase = 0;
- port->port.membase = NULL;
- port->port.regshift = 0;
- }
- return 0;
+ return pci_setup_port(priv->dev, port, bar, offset, regshift);
}

/*
diff --git a/drivers/tty/serial/8250/8250_pci1xxxx.c b/drivers/tty/serial/8250/8250_pci1xxxx.c
new file mode 100644
index 000000000000..e74e8d63daee
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_pci1xxxx.c
@@ -0,0 +1,370 @@
+// 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 <asm/byteorder.h>
+#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 "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 0xa002
+#define PCI_SUBDEVICE_ID_EFAR_PCI11010 0xa012
+#define PCI_SUBDEVICE_ID_EFAR_PCI11101 0xa022
+#define PCI_SUBDEVICE_ID_EFAR_PCI11400 0xa032
+#define PCI_SUBDEVICE_ID_EFAR_PCI11414 0xa042
+
+#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 (62.5 * HZ_PER_MHZ)
+
+#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)
+
+struct pci1xxxx_8250 {
+ struct pci_dev *dev;
+ 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_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;
+ 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:
+ default:
+ return 1;
+ }
+}
+
+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)) /
+ UART_BIT_SAMPLE_CNT) * 255) / 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_setup(struct pci1xxxx_8250 *priv,
+ struct uart_8250_port *port, int idx)
+{
+ int first_offset;
+ int offset;
+ int ret;
+
+ switch (priv->dev->subsystem_device) {
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p1:
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p12:
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p123:
+ first_offset = 256;
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p2:
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p23:
+ first_offset = 512;
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p3:
+ first_offset = 768;
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p02:
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p023:
+ if (idx > 0)
+ idx++;
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p03:
+ if (idx > 0)
+ idx += 2;
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p13:
+ first_offset = 256;
+ if (idx > 0)
+ idx++;
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p013:
+ if (idx > 1)
+ idx++;
+ break;
+ default:
+ first_offset = 0;
+ break;
+ }
+
+ offset = first_offset + idx * 256;
+ 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;
+ ret = pci_setup_port(priv->dev, port, 0, offset, 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 void pci1xxxx_irq_assign(struct pci1xxxx_8250 *priv,
+ struct uart_8250_port *uart, int idx)
+{
+ switch (priv->dev->subsystem_device) {
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p1:
+ uart->port.irq = pci_irq_vector(priv->dev, 1);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p2:
+ uart->port.irq = pci_irq_vector(priv->dev, 2);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p3:
+ uart->port.irq = pci_irq_vector(priv->dev, 3);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p01:
+ uart->port.irq = pci_irq_vector(priv->dev, idx);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p02:
+ if (idx > 0)
+ idx++;
+ uart->port.irq = pci_irq_vector(priv->dev, idx);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p03:
+ if (idx > 0)
+ idx += 2;
+ uart->port.irq = pci_irq_vector(priv->dev, idx);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p12:
+ uart->port.irq = pci_irq_vector(priv->dev, idx + 1);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p13:
+ if (idx > 0)
+ idx += 1;
+ uart->port.irq = pci_irq_vector(priv->dev, idx + 1);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_2p23:
+ uart->port.irq = pci_irq_vector(priv->dev, idx + 2);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p012:
+ uart->port.irq = pci_irq_vector(priv->dev, idx);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p013:
+ if (idx > 1)
+ idx++;
+ uart->port.irq = pci_irq_vector(priv->dev, idx);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p023:
+ if (idx > 0)
+ idx++;
+ uart->port.irq = pci_irq_vector(priv->dev, idx);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_3p123:
+ uart->port.irq = pci_irq_vector(priv->dev, idx + 1);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_4p:
+ case PCI_SUBDEVICE_ID_EFAR_PCI11414:
+ uart->port.irq = pci_irq_vector(priv->dev, idx);
+ break;
+ case PCI_SUBDEVICE_ID_EFAR_PCI1XXXX_1p0:
+ 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:
+ uart->port.irq = pci_irq_vector(priv->dev, 0);
+ break;
+ }
+}
+
+static int pci1xxxx_serial_probe(struct pci_dev *dev,
+ const struct pci_device_id *ent)
+{
+ unsigned int nr_ports, i, j;
+ struct pci1xxxx_8250 *priv;
+ struct uart_8250_port uart;
+ int num_vectors = 0;
+ int rc;
+
+ rc = pcim_enable_device(dev);
+ if (rc)
+ return rc;
+
+ nr_ports = pci1xxxx_get_num_ports(dev);
+
+ priv = devm_kzalloc(&dev->dev, struct_size(priv, line, nr_ports),
+ GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->membase = pcim_iomap(dev, 0, 0);
+ priv->dev = dev;
+ priv->nr = nr_ports;
+ pci_set_master(dev);
+
+ num_vectors = pci_alloc_irq_vectors(dev, 1, 4, PCI_IRQ_ALL_TYPES);
+ if (num_vectors < 0)
+ 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->dev;
+
+ if (num_vectors == 4)
+ writeb(UART_PCI_CTRL_SET_MULTIPLE_MSI,
+ priv->membase + UART_PCI_CTRL_REG);
+ else
+ uart.port.irq = pci_irq_vector(dev, 0);
+
+ for (i = 0; i < nr_ports; i++) {
+ if (num_vectors == 4)
+ pci1xxxx_irq_assign(priv, &uart, i);
+
+ priv->line[i] = -ENOSPC;
+ rc = pci1xxxx_setup(priv, &uart, i);
+ if (rc) {
+ dev_err(&dev->dev, "Failed to setup port %u\n", i);
+ break;
+ }
+ priv->line[i] = serial8250_register_8250_port(&uart);
+
+ if (priv->line[i] < 0) {
+ for (j = i + 1; j < nr_ports; j++)
+ priv->line[j] = -ENOSPC;
+
+ dev_err(&dev->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]);
+ break;
+ }
+ }
+
+ pci_set_drvdata(dev, priv);
+
+ return 0;
+}
+
+static void pci1xxxx_serial_remove(struct pci_dev *dev)
+{
+ struct pci1xxxx_8250 *priv = pci_get_drvdata(dev);
+ int i;
+
+ for (i = 0; i < priv->nr; i++) {
+ if (priv->line[i] >= 0)
+ serial8250_unregister_port(priv->line[i]);
+ }
+}
+
+static const struct pci_device_id pci1xxxx_pci_tbl[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_PCI11010) },
+ { PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_PCI11101) },
+ { PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_PCI11400) },
+ { PCI_DEVICE(PCI_VENDOR_ID_EFAR, PCI_DEVICE_ID_EFAR_PCI11414) },
+ { PCI_DEVICE(PCI_VENDOR_ID_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,
+ .id_table = pci1xxxx_pci_tbl,
+};
+
+module_pci_driver(pci1xxxx_pci_driver);
+
+MODULE_DESCRIPTION("Microchip Technology Inc. PCIe to UART module");
+MODULE_AUTHOR("Kumaravel Thiagarajan <[email protected]>");
+MODULE_AUTHOR("Tharun Kumar P <[email protected]>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/tty/serial/8250/8250_pcilib.c b/drivers/tty/serial/8250/8250_pcilib.c
new file mode 100644
index 000000000000..07040781b43f
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_pcilib.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Microchip pci1xxxx 8250 library. */
+
+#include <linux/pci.h>
+#include "8250.h"
+
+int pci_setup_port(struct pci_dev *dev, struct uart_8250_port *port,
+ u8 bar, unsigned int offset, int regshift)
+{
+ if (bar >= PCI_STD_NUM_BARS)
+ return -EINVAL;
+
+ if (pci_resource_flags(dev, bar) & IORESOURCE_MEM) {
+ if (!pcim_iomap(dev, bar, 0) && !pcim_iomap_table(dev))
+ return -ENOMEM;
+
+ port->port.iotype = UPIO_MEM;
+ port->port.iobase = 0;
+ port->port.mapbase = pci_resource_start(dev, bar) + offset;
+ port->port.membase = pcim_iomap_table(dev)[bar] + offset;
+ port->port.regshift = regshift;
+ } else {
+ port->port.iotype = UPIO_PORT;
+ port->port.iobase = pci_resource_start(dev, bar) + offset;
+ port->port.mapbase = 0;
+ port->port.membase = NULL;
+ port->port.regshift = 0;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pci_setup_port);
diff --git a/drivers/tty/serial/8250/8250_pcilib.h b/drivers/tty/serial/8250/8250_pcilib.h
new file mode 100644
index 000000000000..c33b7eb44222
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_pcilib.h
@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Microchip pci1xxxx 8250 library header file. */
+
+int pci_setup_port(struct pci_dev *dev, struct uart_8250_port *port, u8 bar,
+ unsigned int offset, int regshift);
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 1d2a43214b48..ec2fe5fd7b02 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -313,6 +313,14 @@ static const struct serial8250_config uart_config[] = {
.rxtrig_bytes = {1, 4, 8, 14},
.flags = UART_CAP_FIFO,
},
+ [PORT_MCHP16550A] = {
+ .name = "MCHP16550A",
+ .fifo_size = 256,
+ .tx_loadsz = 256,
+ .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01,
+ .rxtrig_bytes = {2, 66, 130, 194},
+ .flags = UART_CAP_FIFO,
+ },
};

/* Uart divisor latch read */
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index d0b49e15fbf5..f67542470eae 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -132,6 +132,7 @@ config SERIAL_8250_DMA
config SERIAL_8250_PCI
tristate "8250/16550 PCI device support"
depends on SERIAL_8250 && PCI
+ select SERIAL_8250_PCILIB
default SERIAL_8250
help
This builds standard PCI serial support. You may be able to
@@ -291,6 +292,17 @@ config SERIAL_8250_HUB6
To compile this driver as a module, choose M here: the module
will be called 8250_hub6.

+config SERIAL_8250_PCI1XXXX
+ tristate "Microchip 8250 based serial port"
+ depends on SERIAL_8250_PCI
+ select SERIAL_8250_PCILIB
+ default SERIAL_8250
+ help
+ Select this option if you have a setup with Microchip PCIe
+ Switch with serial port enabled and wish to enable 8250
+ serial driver for the serial interface. This driver support
+ will ensure to support baud rates upto 1.5Mpbs.
+
#
# Misc. options/drivers.
#
@@ -500,6 +512,9 @@ config SERIAL_8250_MID
Intel Medfield SOC and various other Intel platforms that is not
covered by the more generic SERIAL_8250_PCI option.

+config SERIAL_8250_PCILIB
+ bool
+
config SERIAL_8250_PERICOM
tristate "Support for Pericom and Acces I/O serial ports"
default SERIAL_8250
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
index bee908f99ea0..98202fdf39f8 100644
--- a/drivers/tty/serial/8250/Makefile
+++ b/drivers/tty/serial/8250/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_SERIAL_8250) += 8250.o 8250_base.o
8250_base-$(CONFIG_SERIAL_8250_DMA) += 8250_dma.o
8250_base-$(CONFIG_SERIAL_8250_DWLIB) += 8250_dwlib.o
8250_base-$(CONFIG_SERIAL_8250_FINTEK) += 8250_fintek.o
+8250_base-$(CONFIG_SERIAL_8250_PCILIB) += 8250_pcilib.o
obj-$(CONFIG_SERIAL_8250_GSC) += 8250_gsc.o
obj-$(CONFIG_SERIAL_8250_PCI) += 8250_pci.o
obj-$(CONFIG_SERIAL_8250_EXAR) += 8250_exar.o
@@ -26,6 +27,7 @@ obj-$(CONFIG_SERIAL_8250_ACCENT) += 8250_accent.o
obj-$(CONFIG_SERIAL_8250_BOCA) += 8250_boca.o
obj-$(CONFIG_SERIAL_8250_EXAR_ST16C554) += 8250_exar_st16c554.o
obj-$(CONFIG_SERIAL_8250_HUB6) += 8250_hub6.o
+obj-$(CONFIG_SERIAL_8250_PCI1XXXX) += 8250_pci1xxxx.o
obj-$(CONFIG_SERIAL_8250_FSL) += 8250_fsl.o
obj-$(CONFIG_SERIAL_8250_MEN_MCB) += 8250_men_mcb.o
obj-$(CONFIG_SERIAL_8250_DW) += 8250_dw.o
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index 3ba34d8378bd..281fa286555c 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -207,6 +207,9 @@
/* Atheros AR933X SoC */
#define PORT_AR933X 99

+/* MCHP 16550A UART with 256 byte FIFOs */
+#define PORT_MCHP16550A 100
+
/* ARC (Synopsys) on-chip UART */
#define PORT_ARC 101

--
2.25.1



2022-11-09 12:46:07

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH v3 tty-next 1/3] 8250: microchip: pci1xxxx: Add driver for quad-uart support.

On Mon, Nov 07, 2022 at 06:15:15PM +0530, Kumaravel Thiagarajan wrote:
> +++ b/drivers/tty/serial/8250/8250_pcilib.c
> @@ -0,0 +1,31 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/* Microchip pci1xxxx 8250 library. */

Better name and a copyright line?

> +
> +#include <linux/pci.h>
> +#include "8250.h"
> +
> +int pci_setup_port(struct pci_dev *dev, struct uart_8250_port *port,
> + u8 bar, unsigned int offset, int regshift)
> +{
> + if (bar >= PCI_STD_NUM_BARS)
> + return -EINVAL;
> +
> + if (pci_resource_flags(dev, bar) & IORESOURCE_MEM) {
> + if (!pcim_iomap(dev, bar, 0) && !pcim_iomap_table(dev))
> + return -ENOMEM;
> +
> + port->port.iotype = UPIO_MEM;
> + port->port.iobase = 0;
> + port->port.mapbase = pci_resource_start(dev, bar) + offset;
> + port->port.membase = pcim_iomap_table(dev)[bar] + offset;
> + port->port.regshift = regshift;
> + } else {
> + port->port.iotype = UPIO_PORT;
> + port->port.iobase = pci_resource_start(dev, bar) + offset;
> + port->port.mapbase = 0;
> + port->port.membase = NULL;
> + port->port.regshift = 0;
> + }
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(pci_setup_port);

This needs a better name, 8250_pci_setup_port()? This is not a pci core
function.

thanks,

greg k-h

2022-11-10 17:44:24

by Kumaravel Thiagarajan

[permalink] [raw]
Subject: RE: [PATCH v3 tty-next 1/3] 8250: microchip: pci1xxxx: Add driver for quad-uart support.

> -----Original Message-----
> From: Greg KH <[email protected]>
> Sent: Wednesday, November 9, 2022 5:31 PM
> To: Kumaravel Thiagarajan - I21417 <[email protected]>
> Subject: Re: [PATCH v3 tty-next 1/3] 8250: microchip: pci1xxxx: Add driver for
> quad-uart support.
>
> On Mon, Nov 07, 2022 at 06:15:15PM +0530, Kumaravel Thiagarajan wrote:
> > +++ b/drivers/tty/serial/8250/8250_pcilib.c
> > @@ -0,0 +1,31 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/* Microchip pci1xxxx 8250 library. */
>
> Better name and a copyright line?
Yes Greg. I think "8250 PCI library" would be the correct name. Is that fine?
Regarding the copyright, we moved the "setup_port" function from 8250_pci.c to this new file.
Can I use the same copyright statement from 8250_pci.c "Copyright (C) 2001 Russell King, All Rights Reserved."?

>
> > +
> > +#include <linux/pci.h>
> > +#include "8250.h"
> > +
> > +int pci_setup_port(struct pci_dev *dev, struct uart_8250_port *port,
> > + u8 bar, unsigned int offset, int regshift) {
> > + if (bar >= PCI_STD_NUM_BARS)
> > + return -EINVAL;
> > +
> > + if (pci_resource_flags(dev, bar) & IORESOURCE_MEM) {
> > + if (!pcim_iomap(dev, bar, 0) && !pcim_iomap_table(dev))
> > + return -ENOMEM;
> > +
> > + port->port.iotype = UPIO_MEM;
> > + port->port.iobase = 0;
> > + port->port.mapbase = pci_resource_start(dev, bar) + offset;
> > + port->port.membase = pcim_iomap_table(dev)[bar] + offset;
> > + port->port.regshift = regshift;
> > + } else {
> > + port->port.iotype = UPIO_PORT;
> > + port->port.iobase = pci_resource_start(dev, bar) + offset;
> > + port->port.mapbase = 0;
> > + port->port.membase = NULL;
> > + port->port.regshift = 0;
> > + }
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(pci_setup_port);
>
> This needs a better name, 8250_pci_setup_port()? This is not a pci core
> function.
Yes. I will rename as you mentioned.

Thank You.

Regards,
Kumar

2022-11-10 18:18:01

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH v3 tty-next 1/3] 8250: microchip: pci1xxxx: Add driver for quad-uart support.

On Thu, Nov 10, 2022 at 05:18:46PM +0000, [email protected] wrote:
> > -----Original Message-----
> > From: Greg KH <[email protected]>
> > Sent: Wednesday, November 9, 2022 5:31 PM
> > To: Kumaravel Thiagarajan - I21417 <[email protected]>
> > Subject: Re: [PATCH v3 tty-next 1/3] 8250: microchip: pci1xxxx: Add driver for
> > quad-uart support.
> >
> > On Mon, Nov 07, 2022 at 06:15:15PM +0530, Kumaravel Thiagarajan wrote:
> > > +++ b/drivers/tty/serial/8250/8250_pcilib.c
> > > @@ -0,0 +1,31 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +/* Microchip pci1xxxx 8250 library. */
> >
> > Better name and a copyright line?
> Yes Greg. I think "8250 PCI library" would be the correct name. Is that fine?

That would be good as obviously it's not a microchip-only thing here.

> Regarding the copyright, we moved the "setup_port" function from 8250_pci.c to this new file.
> Can I use the same copyright statement from 8250_pci.c "Copyright (C) 2001 Russell King, All Rights Reserved."?

Yes, that would be good.

thanks,

greg k-h