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tty: serial: uartlite: Add clock adaptation 

Add support of Common Clock Framework for Uartlite driver.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
hifive-unleashed-5.1
Shubhrajyoti Datta 2018-07-21 17:19:05 +05:30 committed by Greg Kroah-Hartman
parent da7bf20e77
commit 14288befeb
1 changed files with 47 additions and 2 deletions
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49
drivers/tty/serial/uartlite.c
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@ -21,6 +21,7 @@
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/clk.h>
#define ULITE_NAME "ttyUL"
#define ULITE_MAJOR 204
@ -56,6 +57,7 @@
struct uartlite_data {
const struct uartlite_reg_ops *reg_ops;
struct clk *clk;
};
struct uartlite_reg_ops {
@ -261,8 +263,15 @@ static void ulite_break_ctl(struct uart_port *port, int ctl)
static int ulite_startup(struct uart_port *port)
{
struct uartlite_data *pdata = port->private_data;
int ret;
ret = clk_enable(pdata->clk);
if (ret) {
dev_err(port->dev, "Failed to enable clock\n");
return ret;
}
ret = request_irq(port->irq, ulite_isr, IRQF_SHARED | IRQF_TRIGGER_RISING,
"uartlite", port);
if (ret)
@ -277,9 +286,12 @@ static int ulite_startup(struct uart_port *port)
static void ulite_shutdown(struct uart_port *port)
{
struct uartlite_data *pdata = port->private_data;
uart_out32(0, ULITE_CONTROL, port);
uart_in32(ULITE_CONTROL, port); /* dummy */
free_irq(port->irq, port);
clk_disable(pdata->clk);
}
static void ulite_set_termios(struct uart_port *port, struct ktermios *termios,
@ -370,6 +382,17 @@ static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser)
return -EINVAL;
}
static void ulite_pm(struct uart_port *port, unsigned int state,
unsigned int oldstate)
{
struct uartlite_data *pdata = port->private_data;
if (!state)
clk_enable(pdata->clk);
else
clk_disable(pdata->clk);
}
#ifdef CONFIG_CONSOLE_POLL
static int ulite_get_poll_char(struct uart_port *port)
{
@ -405,6 +428,7 @@ static const struct uart_ops ulite_ops = {
.request_port = ulite_request_port,
.config_port = ulite_config_port,
.verify_port = ulite_verify_port,
.pm = ulite_pm,
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = ulite_get_poll_char,
.poll_put_char = ulite_put_poll_char,
@ -669,7 +693,6 @@ static int ulite_release(struct device *dev)
/* ---------------------------------------------------------------------
* Platform bus binding
*/
#if defined(CONFIG_OF)
/* Match table for of_platform binding */
static const struct of_device_id ulite_of_match[] = {
@ -684,7 +707,7 @@ static int ulite_probe(struct platform_device *pdev)
{
struct resource *res;
struct uartlite_data *pdata;
int irq;
int irq, ret;
int id = pdev->id;
#ifdef CONFIG_OF
const __be32 *prop;
@ -706,11 +729,33 @@ static int ulite_probe(struct platform_device *pdev)
if (irq <= 0)
return -ENXIO;
pdata->clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
if (IS_ERR(pdata->clk)) {
if (PTR_ERR(pdata->clk) != -ENOENT)
return PTR_ERR(pdata->clk);
/*
* Clock framework support is optional, continue on
* anyways if we don't find a matching clock.
*/
pdata->clk = NULL;
}
ret = clk_prepare(pdata->clk);
if (ret) {
dev_err(&pdev->dev, "Failed to prepare clock\n");
return ret;
}
return ulite_assign(&pdev->dev, id, res->start, irq, pdata);
}
static int ulite_remove(struct platform_device *pdev)
{
struct uart_port *port = dev_get_drvdata(&pdev->dev);
struct uartlite_data *pdata = port->private_data;
clk_disable_unprepare(pdata->clk);
return ulite_release(&pdev->dev);
}