[PATCHv4 3/9] serial: vt8500: Add devicetree support for vt8500-serial
Tony Prisk
linux at prisktech.co.nz
Wed Aug 22 02:37:36 EDT 2012
Increase vt8500_max_ports to 6 as the WM8505 has 6 available uarts.
Added max_ports range checking to prevent addressing overflow.
Use devicetree port id as primary addressing for ports but allow
auto-allocation if id not specified.
Signed-off-by: Tony Prisk <linux at prisktech.co.nz>
---
drivers/tty/serial/vt8500_serial.c | 44 ++++++++++++++++++++++++++++++++----
1 file changed, 40 insertions(+), 4 deletions(-)
diff --git a/drivers/tty/serial/vt8500_serial.c b/drivers/tty/serial/vt8500_serial.c
index 2be006f..c10e21a 100644
--- a/drivers/tty/serial/vt8500_serial.c
+++ b/drivers/tty/serial/vt8500_serial.c
@@ -34,6 +34,7 @@
#include <linux/slab.h>
#include <linux/clk.h>
#include <linux/platform_device.h>
+#include <linux/of.h>
/*
* UART Register offsets
@@ -76,6 +77,8 @@
#define RX_FIFO_INTS (RXFAF | RXFF | RXOVER | PER | FER | RXTOUT)
#define TX_FIFO_INTS (TXFAE | TXFE | TXUDR)
+#define VT8500_MAX_PORTS 6
+
struct vt8500_port {
struct uart_port uart;
char name[16];
@@ -83,6 +86,13 @@ struct vt8500_port {
unsigned int ier;
};
+/*
+ * we use this variable to keep track of which ports
+ * have been allocated as we can't use pdev->id in
+ * devicetree
+ */
+static unsigned long vt8500_ports_in_use;
+
static inline void vt8500_write(struct uart_port *port, unsigned int val,
unsigned int off)
{
@@ -431,7 +441,7 @@ static int vt8500_verify_port(struct uart_port *port,
return 0;
}
-static struct vt8500_port *vt8500_uart_ports[4];
+static struct vt8500_port *vt8500_uart_ports[VT8500_MAX_PORTS];
static struct uart_driver vt8500_uart_driver;
#ifdef CONFIG_SERIAL_VT8500_CONSOLE
@@ -548,7 +558,9 @@ static int __devinit vt8500_serial_probe(struct platform_device *pdev)
{
struct vt8500_port *vt8500_port;
struct resource *mmres, *irqres;
+ struct device_node *np = pdev->dev.of_node;
int ret;
+ int port;
mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
irqres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
@@ -559,13 +571,31 @@ static int __devinit vt8500_serial_probe(struct platform_device *pdev)
if (!vt8500_port)
return -ENOMEM;
+ if (np)
+ port = of_alias_get_id(np, "serial");
+
+ if (port < 0) {
+ /* calculate the port id */
+ port = find_first_zero_bit(&vt8500_ports_in_use,
+ sizeof(vt8500_ports_in_use));
+ }
+
+ if (port > VT8500_MAX_PORTS)
+ return -ENODEV;
+
+ /* reserve the port id */
+ if (test_and_set_bit(port, &vt8500_ports_in_use)) {
+ /* port already in use - shouldn't really happen */
+ return -EBUSY;
+ }
+
vt8500_port->uart.type = PORT_VT8500;
vt8500_port->uart.iotype = UPIO_MEM;
vt8500_port->uart.mapbase = mmres->start;
vt8500_port->uart.irq = irqres->start;
vt8500_port->uart.fifosize = 16;
vt8500_port->uart.ops = &vt8500_uart_pops;
- vt8500_port->uart.line = pdev->id;
+ vt8500_port->uart.line = port;
vt8500_port->uart.dev = &pdev->dev;
vt8500_port->uart.flags = UPF_IOREMAP | UPF_BOOT_AUTOCONF;
vt8500_port->uart.uartclk = 24000000;
@@ -579,7 +609,7 @@ static int __devinit vt8500_serial_probe(struct platform_device *pdev)
goto err;
}
- vt8500_uart_ports[pdev->id] = vt8500_port;
+ vt8500_uart_ports[port] = vt8500_port;
uart_add_one_port(&vt8500_uart_driver, &vt8500_port->uart);
@@ -603,12 +633,18 @@ static int __devexit vt8500_serial_remove(struct platform_device *pdev)
return 0;
}
+static const struct of_device_id wmt_dt_ids[] = {
+ { .compatible = "via,vt8500-uart", },
+ {}
+};
+
static struct platform_driver vt8500_platform_driver = {
.probe = vt8500_serial_probe,
.remove = __devexit_p(vt8500_serial_remove),
.driver = {
.name = "vt8500_serial",
.owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(wmt_dt_ids),
},
};
@@ -642,4 +678,4 @@ module_exit(vt8500_serial_exit);
MODULE_AUTHOR("Alexey Charkov <alchark at gmail.com>");
MODULE_DESCRIPTION("Driver for vt8500 serial device");
-MODULE_LICENSE("GPL");
+MODULE_LICENSE("GPL v2");
--
1.7.9.5
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