blob: ca95d3ebb64b2a384040c0dc39a055c4f416c713 [file] [log] [blame]
From b86ad34f501f3cb6ebda7d93935749917ab5349c Mon Sep 17 00:00:00 2001
From: David Daney <david.daney@cavium.com>
Date: Wed, 19 Jun 2013 20:37:27 +0000
Subject: tty/8250_dw: Add support for OCTEON UARTS.
A few differences needed by OCTEON:
o These are DWC UARTS, but have USR at a different offset.
o Internal SoC buses require reading back from registers to maintain
write ordering.
o 8250 on OCTEON appears with 64-bit wide registers, so when using
readb/writeb in big endian mode we have to adjust the membase to hit
the proper part of the register.
o No UCV register, so we hard code some properties.
Because OCTEON doesn't have a UCV register, I change where
dw8250_setup_port(), which reads the UCV, is called by pushing it in
to the OF and ACPI probe functions, and move unchanged
dw8250_setup_port() earlier in the file.
Signed-off-by: David Daney <david.daney@cavium.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: linux-mips@linux-mips.org
Cc: Jamie Iles <jamie@jamieiles.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/5516/
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit d5f1af7ece96cf52e0b110c72210ac15c2f65438)
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
---
drivers/tty/serial/8250/8250_dw.c | 106 ++++++++++++++++++++++++--------------
1 file changed, 68 insertions(+), 38 deletions(-)
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -29,6 +29,8 @@
#include <linux/clk.h>
#include <linux/pm_runtime.h>
+#include <asm/byteorder.h>
+
#include "8250.h"
/* Offsets for the DesignWare specific registers */
@@ -57,6 +59,7 @@ struct dw8250_data {
int last_mcr;
int line;
struct clk *clk;
+ u8 usr_reg;
};
static inline int dw8250_modify_msr(struct uart_port *p, int offset, int value)
@@ -112,6 +115,13 @@ static unsigned int dw8250_serial_in(str
return dw8250_modify_msr(p, offset, value);
}
+/* Read Back (rb) version to ensure register access ording. */
+static void dw8250_serial_out_rb(struct uart_port *p, int offset, int value)
+{
+ dw8250_serial_out(p, offset, value);
+ dw8250_serial_in(p, UART_LCR);
+}
+
static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
{
struct dw8250_data *d = p->private_data;
@@ -153,7 +163,7 @@ static int dw8250_handle_irq(struct uart
return 1;
} else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) {
/* Clear the USR */
- (void)p->serial_in(p, DW_UART_USR);
+ (void)p->serial_in(p, d->usr_reg);
return 1;
}
@@ -173,12 +183,60 @@ dw8250_do_pm(struct uart_port *port, uns
pm_runtime_put_sync_suspend(port->dev);
}
-static int dw8250_probe_of(struct uart_port *p)
+static void dw8250_setup_port(struct uart_8250_port *up)
+{
+ struct uart_port *p = &up->port;
+ u32 reg = readl(p->membase + DW_UART_UCV);
+
+ /*
+ * If the Component Version Register returns zero, we know that
+ * ADDITIONAL_FEATURES are not enabled. No need to go any further.
+ */
+ if (!reg)
+ return;
+
+ dev_dbg_ratelimited(p->dev, "Designware UART version %c.%c%c\n",
+ (reg >> 24) & 0xff, (reg >> 16) & 0xff, (reg >> 8) & 0xff);
+
+ reg = readl(p->membase + DW_UART_CPR);
+ if (!reg)
+ return;
+
+ /* Select the type based on fifo */
+ if (reg & DW_UART_CPR_FIFO_MODE) {
+ p->type = PORT_16550A;
+ p->flags |= UPF_FIXED_TYPE;
+ p->fifosize = DW_UART_CPR_FIFO_SIZE(reg);
+ up->tx_loadsz = p->fifosize;
+ up->capabilities = UART_CAP_FIFO;
+ }
+
+ if (reg & DW_UART_CPR_AFCE_MODE)
+ up->capabilities |= UART_CAP_AFE;
+}
+
+static int dw8250_probe_of(struct uart_port *p,
+ struct dw8250_data *data)
{
struct device_node *np = p->dev->of_node;
u32 val;
+ bool has_ucv = true;
- if (!of_property_read_u32(np, "reg-io-width", &val)) {
+ if (of_device_is_compatible(np, "cavium,octeon-3860-uart")) {
+#ifdef __BIG_ENDIAN
+ /*
+ * Low order bits of these 64-bit registers, when
+ * accessed as a byte, are 7 bytes further down in the
+ * address space in big endian mode.
+ */
+ p->membase += 7;
+#endif
+ p->serial_out = dw8250_serial_out_rb;
+ p->flags = ASYNC_SKIP_TEST | UPF_SHARE_IRQ | UPF_FIXED_TYPE;
+ p->type = PORT_OCTEON;
+ data->usr_reg = 0x27;
+ has_ucv = false;
+ } else if (!of_property_read_u32(np, "reg-io-width", &val)) {
switch (val) {
case 1:
break;
@@ -192,6 +250,8 @@ static int dw8250_probe_of(struct uart_p
return -EINVAL;
}
}
+ if (has_ucv)
+ dw8250_setup_port(container_of(p, struct uart_8250_port, port));
if (!of_property_read_u32(np, "reg-shift", &val))
p->regshift = val;
@@ -216,6 +276,8 @@ static int dw8250_probe_acpi(struct uart
const struct acpi_device_id *id;
struct uart_port *p = &up->port;
+ dw8250_setup_port(up);
+
id = acpi_match_device(p->dev->driver->acpi_match_table, p->dev);
if (!id)
return -ENODEV;
@@ -244,38 +306,6 @@ static inline int dw8250_probe_acpi(stru
}
#endif /* CONFIG_ACPI */
-static void dw8250_setup_port(struct uart_8250_port *up)
-{
- struct uart_port *p = &up->port;
- u32 reg = readl(p->membase + DW_UART_UCV);
-
- /*
- * If the Component Version Register returns zero, we know that
- * ADDITIONAL_FEATURES are not enabled. No need to go any further.
- */
- if (!reg)
- return;
-
- dev_dbg_ratelimited(p->dev, "Designware UART version %c.%c%c\n",
- (reg >> 24) & 0xff, (reg >> 16) & 0xff, (reg >> 8) & 0xff);
-
- reg = readl(p->membase + DW_UART_CPR);
- if (!reg)
- return;
-
- /* Select the type based on fifo */
- if (reg & DW_UART_CPR_FIFO_MODE) {
- p->type = PORT_16550A;
- p->flags |= UPF_FIXED_TYPE;
- p->fifosize = DW_UART_CPR_FIFO_SIZE(reg);
- up->tx_loadsz = p->fifosize;
- up->capabilities = UART_CAP_FIFO;
- }
-
- if (reg & DW_UART_CPR_AFCE_MODE)
- up->capabilities |= UART_CAP_AFE;
-}
-
static int dw8250_probe(struct platform_device *pdev)
{
struct uart_8250_port uart = {};
@@ -307,6 +337,7 @@ static int dw8250_probe(struct platform_
if (!data)
return -ENOMEM;
+ data->usr_reg = DW_UART_USR;
data->clk = devm_clk_get(&pdev->dev, NULL);
if (!IS_ERR(data->clk)) {
clk_prepare_enable(data->clk);
@@ -318,10 +349,8 @@ static int dw8250_probe(struct platform_
uart.port.serial_out = dw8250_serial_out;
uart.port.private_data = data;
- dw8250_setup_port(&uart);
-
if (pdev->dev.of_node) {
- err = dw8250_probe_of(&uart.port);
+ err = dw8250_probe_of(&uart.port, data);
if (err)
return err;
} else if (ACPI_HANDLE(&pdev->dev)) {
@@ -410,6 +439,7 @@ static const struct dev_pm_ops dw8250_pm
static const struct of_device_id dw8250_of_match[] = {
{ .compatible = "snps,dw-apb-uart" },
+ { .compatible = "cavium,octeon-3860-uart" },
{ /* Sentinel */ }
};
MODULE_DEVICE_TABLE(of, dw8250_of_match);