diff options
| author | Cyrille Pitchen <cyrille.pitchen@atmel.com> | 2014-12-09 14:31:33 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-03-06 14:57:33 -0800 |
| commit | 8155e4a095ba26d5e0204deb3f97aca2296fae5e (patch) | |
| tree | 3a0c19cd30f7ec39658d3b5e12fe5c805b45e010 /drivers | |
| parent | 36ed10d9764d2536f1a9927d7b6ac16703baa2dd (diff) | |
tty/serial: at91: enable peripheral clock before accessing I/O registers
commit d4f641876a68d1961e30c202709cc2d484f69f6f upstream.
atmel_serial_probe() calls atmel_init_port(). In turn, atmel_init_port() calls
clk_disable_unprepare() to disable the peripheral clock before returning.
Later atmel_serial_probe() accesses some I/O registers such as the Mode and
Control registers for RS485 support then the Name and Version registers, through a call to
atmel_get_ip_name(), but at that moment the peripheral clock was still
disabled.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/serial/atmel_serial.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 756f567527c4..c6621dc296c0 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -2596,6 +2596,12 @@ static int atmel_serial_probe(struct platform_device *pdev) device_init_wakeup(&pdev->dev, 1); platform_set_drvdata(pdev, port); + /* + * The peripheral clock has been disabled by atmel_init_port(): + * enable it before accessing I/O registers + */ + clk_prepare_enable(port->clk); + if (rs485_enabled) { UART_PUT_MR(&port->uart, ATMEL_US_USMODE_NORMAL); UART_PUT_CR(&port->uart, ATMEL_US_RTSEN); @@ -2606,6 +2612,12 @@ static int atmel_serial_probe(struct platform_device *pdev) */ atmel_get_ip_name(&port->uart); + /* + * The peripheral clock can now safely be disabled till the port + * is used + */ + clk_disable_unprepare(port->clk); + return 0; err_add_port: |