tty: xuartps: disable clocks when not used
Currently the clocks are enabled at probe and disabled
at remove. Instead enable the clocks when used.
Signed-off-by: Shubhrajyoti Datta <shubhraj@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index cd46e64..9ca1a4d 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -976,6 +976,23 @@
}
#endif
+static void cdns_uart_pm(struct uart_port *port, unsigned int state,
+ unsigned int oldstate)
+{
+ struct cdns_uart *cdns_uart = port->private_data;
+
+ switch (state) {
+ case UART_PM_STATE_OFF:
+ clk_disable(cdns_uart->uartclk);
+ clk_disable(cdns_uart->pclk);
+ break;
+ default:
+ clk_enable(cdns_uart->pclk);
+ clk_enable(cdns_uart->uartclk);
+ break;
+ }
+}
+
static struct uart_ops cdns_uart_ops = {
.set_mctrl = cdns_uart_set_mctrl,
.get_mctrl = cdns_uart_get_mctrl,
@@ -987,6 +1004,7 @@
.set_termios = cdns_uart_set_termios,
.startup = cdns_uart_startup,
.shutdown = cdns_uart_shutdown,
+ .pm = cdns_uart_pm,
.type = cdns_uart_type,
.verify_port = cdns_uart_verify_port,
.request_port = cdns_uart_request_port,
@@ -1350,12 +1368,12 @@
return PTR_ERR(cdns_uart_data->uartclk);
}
- rc = clk_prepare_enable(cdns_uart_data->pclk);
+ rc = clk_prepare(cdns_uart_data->pclk);
if (rc) {
dev_err(&pdev->dev, "Unable to enable pclk clock.\n");
return rc;
}
- rc = clk_prepare_enable(cdns_uart_data->uartclk);
+ rc = clk_prepare(cdns_uart_data->uartclk);
if (rc) {
dev_err(&pdev->dev, "Unable to enable device clock.\n");
goto err_out_clk_dis_pclk;
@@ -1422,9 +1440,9 @@
&cdns_uart_data->clk_rate_change_nb);
#endif
err_out_clk_disable:
- clk_disable_unprepare(cdns_uart_data->uartclk);
+ clk_unprepare(cdns_uart_data->uartclk);
err_out_clk_dis_pclk:
- clk_disable_unprepare(cdns_uart_data->pclk);
+ clk_unprepare(cdns_uart_data->pclk);
return rc;
}
@@ -1448,8 +1466,8 @@
#endif
rc = uart_remove_one_port(&cdns_uart_uart_driver, port);
port->mapbase = 0;
- clk_disable_unprepare(cdns_uart_data->uartclk);
- clk_disable_unprepare(cdns_uart_data->pclk);
+ clk_unprepare(cdns_uart_data->uartclk);
+ clk_unprepare(cdns_uart_data->pclk);
return rc;
}