From: Changqi Hu <changqi.hu@mediatek.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>,
Matthias Brugger <matthias.bgg@gmail.com>
Cc: Changqi Hu <changqi.hu@mediatek.com>,
Peter Shih <pihsun@chromium.org>,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>,
<linux-serial@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-mediatek@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <srv_heupstream@mediatek.com>,
Eddie Huang <eddie.huang@mediatek.com>,
Yingjoe Chen <yingjoe.chen@mediatek.com>
Subject: [PATCH v3] serial: 8250-mtk: modify mtk uart power and clock management
Date: Fri, 19 Jul 2019 10:59:42 +0800 [thread overview]
Message-ID: <1563505182-2408-1-git-send-email-changqi.hu@mediatek.com> (raw)
modify mtk uart runtime interface, add uart clock use count.
merge patch v1 and patch v2 together.
Signed-off-by: Changqi Hu <changqi.hu@mediatek.com>
---
drivers/tty/serial/8250/8250_mtk.c | 50 ++++++++++++++++++++++++--------------
1 file changed, 32 insertions(+), 18 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
index f470ded..a07c8ae 100644
--- a/drivers/tty/serial/8250/8250_mtk.c
+++ b/drivers/tty/serial/8250/8250_mtk.c
@@ -31,6 +31,7 @@
#define MTK_UART_RXTRI_AD 0x14 /* RX Trigger address */
#define MTK_UART_FRACDIV_L 0x15 /* Fractional divider LSB address */
#define MTK_UART_FRACDIV_M 0x16 /* Fractional divider MSB address */
+#define MTK_UART_DEBUG0 0x18
#define MTK_UART_IER_XOFFI 0x20 /* Enable XOFF character interrupt */
#define MTK_UART_IER_RTSI 0x40 /* Enable RTS Modem status interrupt */
#define MTK_UART_IER_CTSI 0x80 /* Enable CTS Modem status interrupt */
@@ -386,9 +387,18 @@ static void mtk8250_set_flow_ctrl(struct uart_8250_port *up, int mode)
static int __maybe_unused mtk8250_runtime_suspend(struct device *dev)
{
struct mtk8250_data *data = dev_get_drvdata(dev);
+ struct uart_8250_port *up = serial8250_get_port(data->line);
- clk_disable_unprepare(data->uart_clk);
- clk_disable_unprepare(data->bus_clk);
+ /* wait until UART in idle status */
+ while
+ (serial_in(up, MTK_UART_DEBUG0));
+
+ if (data->clk_count == 0U) {
+ dev_dbg(dev, "%s clock count is 0\n", __func__);
+ } else {
+ clk_disable_unprepare(data->bus_clk);
+ data->clk_count--;
+ }
return 0;
}
@@ -398,16 +408,16 @@ static int __maybe_unused mtk8250_runtime_resume(struct device *dev)
struct mtk8250_data *data = dev_get_drvdata(dev);
int err;
- err = clk_prepare_enable(data->uart_clk);
- if (err) {
- dev_warn(dev, "Can't enable clock\n");
- return err;
- }
-
- err = clk_prepare_enable(data->bus_clk);
- if (err) {
- dev_warn(dev, "Can't enable bus clock\n");
- return err;
+ if (data->clk_count > 0U) {
+ dev_dbg(dev, "%s clock count is %d\n", __func__,
+ data->clk_count);
+ } else {
+ err = clk_prepare_enable(data->bus_clk);
+ if (err) {
+ dev_warn(dev, "Can't enable bus clock\n");
+ return err;
+ }
+ data->clk_count++;
}
return 0;
@@ -417,12 +427,14 @@ static int __maybe_unused mtk8250_runtime_resume(struct device *dev)
mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
{
if (!state)
- pm_runtime_get_sync(port->dev);
+ if (!mtk8250_runtime_resume(port->dev))
+ pm_runtime_get_sync(port->dev);
serial8250_do_pm(port, state, old);
if (state)
- pm_runtime_put_sync_suspend(port->dev);
+ if (!pm_runtime_put_sync_suspend(port->dev))
+ mtk8250_runtime_suspend(port->dev);
}
#ifdef CONFIG_SERIAL_8250_DMA
@@ -499,6 +511,8 @@ static int mtk8250_probe(struct platform_device *pdev)
if (!data)
return -ENOMEM;
+ data->clk_count = 0;
+
if (pdev->dev.of_node) {
err = mtk8250_probe_of(pdev, &uart.port, data);
if (err)
@@ -531,6 +545,7 @@ static int mtk8250_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, data);
+ pm_runtime_enable(&pdev->dev);
err = mtk8250_runtime_resume(&pdev->dev);
if (err)
return err;
@@ -539,9 +554,6 @@ static int mtk8250_probe(struct platform_device *pdev)
if (data->line < 0)
return data->line;
- pm_runtime_set_active(&pdev->dev);
- pm_runtime_enable(&pdev->dev);
-
return 0;
}
@@ -552,11 +564,13 @@ static int mtk8250_remove(struct platform_device *pdev)
pm_runtime_get_sync(&pdev->dev);
serial8250_unregister_port(data->line);
- mtk8250_runtime_suspend(&pdev->dev);
pm_runtime_disable(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
+ if (!pm_runtime_status_suspended(&pdev->dev))
+ mtk8250_runtime_suspend(&pdev->dev);
+
return 0;
}
--
1.8.1.1.dirty
next reply other threads:[~2019-07-19 2:59 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-19 2:59 Changqi Hu [this message]
2019-07-19 11:16 ` [PATCH v3] serial: 8250-mtk: modify mtk uart power and clock management Matthias Brugger
2019-07-25 9:47 ` Greg Kroah-Hartman
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