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| author | Cyrille Pitchen <cyrille.pitchen@atmel.com> | 2014-12-09 14:31:33 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-09 14:20:49 -0800 |
| commit | d4f641876a68d1961e30c202709cc2d484f69f6f (patch) | |
| tree | 79f2c3a4763afa7ea5ff8d60c2826e4c1578bf73 /drivers/tty/serial/atmel_serial.c | |
| parent | 485819b5b9ed82372dacae775998f3c33717f7fe (diff) | |
| download | linux-d4f641876a68d1961e30c202709cc2d484f69f6f.tar.gz linux-d4f641876a68d1961e30c202709cc2d484f69f6f.tar.xz | |
tty/serial: at91: enable peripheral clock before accessing I/O registers
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>
Cc: <stable@vger.kernel.org> # 3.12+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/atmel_serial.c')
| -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: |