SERIAL: MIPS: lantiq: implement OF support
Add devicetree and handling for our new clkdev clocks. The patch is rather
straightforward. .of_match_table is set and the 3 irqs are now loaded from the
devicetree.
This series converts the lantiq target to clkdev amongst other things. The
driver needs to handle two clocks now. The fpi bus clock used to derive the
divider and the clock gate needed on some socs to make the secondary port work.
Signed-off-by: John Crispin <blogic@openwrt.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alan Cox <alan@linux.intel.com>
Cc: linux-serial@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3809/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
index 96c1cac..02da071 100644
--- a/drivers/tty/serial/lantiq.c
+++ b/drivers/tty/serial/lantiq.c
@@ -31,16 +31,19 @@
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
-#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
#include <linux/io.h>
#include <linux/clk.h>
+#include <linux/gpio.h>
#include <lantiq_soc.h>
#define PORT_LTQ_ASC 111
#define MAXPORTS 2
#define UART_DUMMY_UER_RX 1
-#define DRVNAME "ltq_asc"
+#define DRVNAME "lantiq,asc"
#ifdef __BIG_ENDIAN
#define LTQ_ASC_TBUF (0x0020 + 3)
#define LTQ_ASC_RBUF (0x0024 + 3)
@@ -114,6 +117,9 @@
struct ltq_uart_port {
struct uart_port port;
+ /* clock used to derive divider */
+ struct clk *fpiclk;
+ /* clock gating of the ASC core */
struct clk *clk;
unsigned int tx_irq;
unsigned int rx_irq;
@@ -316,7 +322,9 @@
struct ltq_uart_port *ltq_port = to_ltq_uart_port(port);
int retval;
- port->uartclk = clk_get_rate(ltq_port->clk);
+ if (ltq_port->clk)
+ clk_enable(ltq_port->clk);
+ port->uartclk = clk_get_rate(ltq_port->fpiclk);
ltq_w32_mask(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET),
port->membase + LTQ_ASC_CLC);
@@ -382,6 +390,8 @@
port->membase + LTQ_ASC_RXFCON);
ltq_w32_mask(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU,
port->membase + LTQ_ASC_TXFCON);
+ if (ltq_port->clk)
+ clk_disable(ltq_port->clk);
}
static void
@@ -630,7 +640,7 @@
port = <q_port->port;
- port->uartclk = clk_get_rate(ltq_port->clk);
+ port->uartclk = clk_get_rate(ltq_port->fpiclk);
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
@@ -668,37 +678,32 @@
static int __init
lqasc_probe(struct platform_device *pdev)
{
+ struct device_node *node = pdev->dev.of_node;
struct ltq_uart_port *ltq_port;
struct uart_port *port;
- struct resource *mmres, *irqres;
- int tx_irq, rx_irq, err_irq;
- struct clk *clk;
+ struct resource *mmres, irqres[3];
+ int line = 0;
int ret;
mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- irqres = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
- if (!mmres || !irqres)
+ ret = of_irq_to_resource_table(node, irqres, 3);
+ if (!mmres || (ret != 3)) {
+ dev_err(&pdev->dev,
+ "failed to get memory/irq for serial port\n");
return -ENODEV;
-
- if (pdev->id >= MAXPORTS)
- return -EBUSY;
-
- if (lqasc_port[pdev->id] != NULL)
- return -EBUSY;
-
- clk = clk_get(&pdev->dev, "fpi");
- if (IS_ERR(clk)) {
- pr_err("failed to get fpi clk\n");
- return -ENOENT;
}
- tx_irq = platform_get_irq_byname(pdev, "tx");
- rx_irq = platform_get_irq_byname(pdev, "rx");
- err_irq = platform_get_irq_byname(pdev, "err");
- if ((tx_irq < 0) | (rx_irq < 0) | (err_irq < 0))
- return -ENODEV;
+ /* check if this is the console port */
+ if (mmres->start != CPHYSADDR(LTQ_EARLY_ASC))
+ line = 1;
- ltq_port = kzalloc(sizeof(struct ltq_uart_port), GFP_KERNEL);
+ if (lqasc_port[line]) {
+ dev_err(&pdev->dev, "port %d already allocated\n", line);
+ return -EBUSY;
+ }
+
+ ltq_port = devm_kzalloc(&pdev->dev, sizeof(struct ltq_uart_port),
+ GFP_KERNEL);
if (!ltq_port)
return -ENOMEM;
@@ -709,19 +714,26 @@
port->ops = &lqasc_pops;
port->fifosize = 16;
port->type = PORT_LTQ_ASC,
- port->line = pdev->id;
+ port->line = line;
port->dev = &pdev->dev;
-
- port->irq = tx_irq; /* unused, just to be backward-compatibe */
+ /* unused, just to be backward-compatible */
+ port->irq = irqres[0].start;
port->mapbase = mmres->start;
- ltq_port->clk = clk;
+ ltq_port->fpiclk = clk_get_fpi();
+ if (IS_ERR(ltq_port->fpiclk)) {
+ pr_err("failed to get fpi clk\n");
+ return -ENOENT;
+ }
- ltq_port->tx_irq = tx_irq;
- ltq_port->rx_irq = rx_irq;
- ltq_port->err_irq = err_irq;
+ /* not all asc ports have clock gates, lets ignore the return code */
+ ltq_port->clk = clk_get(&pdev->dev, NULL);
- lqasc_port[pdev->id] = ltq_port;
+ ltq_port->tx_irq = irqres[0].start;
+ ltq_port->rx_irq = irqres[1].start;
+ ltq_port->err_irq = irqres[2].start;
+
+ lqasc_port[line] = ltq_port;
platform_set_drvdata(pdev, ltq_port);
ret = uart_add_one_port(&lqasc_reg, port);
@@ -729,10 +741,17 @@
return ret;
}
+static const struct of_device_id ltq_asc_match[] = {
+ { .compatible = DRVNAME },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ltq_asc_match);
+
static struct platform_driver lqasc_driver = {
.driver = {
.name = DRVNAME,
.owner = THIS_MODULE,
+ .of_match_table = ltq_asc_match,
},
};