serial: imx: remove the uart_console() check

The uart_console() check makes the clocks(clk_per and clk_ipg) opened
even when we close the console uart.

This patch enable/disable the clocks in imx_console_write(),
so we can keep the clocks closed when the console uart is closed.

Also remove the clock enable/disable oprations in the probe, we do not
need them any more.

Signed-off-by: Huang Shijie <[email protected]>
Acked-by: Shawn Guo <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Huang Shijie

drivers/tty/serial/imx.c

@@ -701,15 +701,13 @@ static int imx_startup(struct uart_port *port)
 	int retval;
 	unsigned long flags, temp;
 
-	if (!uart_console(port)) {
-		retval = clk_prepare_enable(sport->clk_per);
-		if (retval)
-			goto error_out1;
-		retval = clk_prepare_enable(sport->clk_ipg);
-		if (retval) {
-			clk_disable_unprepare(sport->clk_per);
-			goto error_out1;
-		}
+	retval = clk_prepare_enable(sport->clk_per);
+	if (retval)
+		goto error_out1;
+	retval = clk_prepare_enable(sport->clk_ipg);
+	if (retval) {
+		clk_disable_unprepare(sport->clk_per);
+		goto error_out1;
 	}
 
 	imx_setup_ufcr(sport, 0);
@@ -900,10 +898,8 @@ static void imx_shutdown(struct uart_port *port)
 	writel(temp, sport->port.membase + UCR1);
 	spin_unlock_irqrestore(&sport->port.lock, flags);
 
-	if (!uart_console(&sport->port)) {
-		clk_disable_unprepare(sport->clk_per);
-		clk_disable_unprepare(sport->clk_ipg);
-	}
+	clk_disable_unprepare(sport->clk_per);
+	clk_disable_unprepare(sport->clk_ipg);
 }
 
 static void
@@ -1250,6 +1246,16 @@ imx_console_write(struct console *co, const char *s, unsigned int count)
 	unsigned int ucr1;
 	unsigned long flags = 0;
 	int locked = 1;
+	int retval;
+
+	retval = clk_enable(sport->clk_per);
+	if (retval)
+		return;
+	retval = clk_enable(sport->clk_ipg);
+	if (retval) {
+		clk_disable(sport->clk_per);
+		return;
+	}
 
 	if (sport->port.sysrq)
 		locked = 0;
@@ -1285,6 +1291,9 @@ imx_console_write(struct console *co, const char *s, unsigned int count)
 
 	if (locked)
 		spin_unlock_irqrestore(&sport->port.lock, flags);
+
+	clk_disable(sport->clk_ipg);
+	clk_disable(sport->clk_per);
 }
 
 /*
@@ -1358,6 +1367,7 @@ imx_console_setup(struct console *co, char *options)
 	int bits = 8;
 	int parity = 'n';
 	int flow = 'n';
+	int retval;
 
 	/*
 	 * Check whether an invalid uart number has been specified, and
@@ -1370,14 +1380,32 @@ imx_console_setup(struct console *co, char *options)
 	if (sport == NULL)
 		return -ENODEV;
 
+	/* For setting the registers, we only need to enable the ipg clock. */
+	retval = clk_prepare_enable(sport->clk_ipg);
+	if (retval)
+		goto error_console;
+
 	if (options)
 		uart_parse_options(options, &baud, &parity, &bits, &flow);
 	else
 		imx_console_get_options(sport, &baud, &parity, &bits);
 
 	imx_setup_ufcr(sport, 0);
 
-	return uart_set_options(&sport->port, co, baud, parity, bits, flow);
+	retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
+
+	clk_disable(sport->clk_ipg);
+	if (retval) {
+		clk_unprepare(sport->clk_ipg);
+		goto error_console;
+	}
+
+	retval = clk_prepare(sport->clk_per);
+	if (retval)
+		clk_disable_unprepare(sport->clk_ipg);
+
+error_console:
+	return retval;
 }
 
 static struct uart_driver imx_reg;
@@ -1555,9 +1583,6 @@ static int serial_imx_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	clk_prepare_enable(sport->clk_per);
-	clk_prepare_enable(sport->clk_ipg);
-
 	sport->port.uartclk = clk_get_rate(sport->clk_per);
 
 	imx_ports[sport->port.line] = sport;
@@ -1566,26 +1591,18 @@ static int serial_imx_probe(struct platform_device *pdev)
 	if (pdata && pdata->init) {
 		ret = pdata->init(pdev);
 		if (ret)
-			goto clkput;
+			return ret;
 	}
 
 	ret = uart_add_one_port(&imx_reg, &sport->port);
 	if (ret)
 		goto deinit;
 	platform_set_drvdata(pdev, sport);
 
-	if (!uart_console(&sport->port)) {
-		clk_disable_unprepare(sport->clk_per);
-		clk_disable_unprepare(sport->clk_ipg);
-	}
-
 	return 0;
 deinit:
 	if (pdata && pdata->exit)
 		pdata->exit(pdev);
-clkput:
-	clk_disable_unprepare(sport->clk_per);
-	clk_disable_unprepare(sport->clk_ipg);
 	return ret;
 }