From: Andy Duan <fugang.duan@nxp.com>
To: "A.s. Dong" <aisheng.dong@nxp.com>,
        "linux-serial@vger.kernel.org" <linux-serial@vger.kernel.org>
CC: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "jslaby@suse.com" <jslaby@suse.com>,
        "stefan@agner.ch" <stefan@agner.ch>, Mingkai Hu <mingkai.hu@nxp.com>,
        "Y.b. Lu" <yangbo.lu@nxp.com>,
        "nikita.yoush@cogentembedded.com" <nikita.yoush@cogentembedded.com>,
        "andy.shevchenko@gmail.com" <andy.shevchenko@gmail.com>,
        "dongas86@gmail.com" <dongas86@gmail.com>,
        "A.s. Dong" <aisheng.dong@nxp.com>
Subject: RE: [PATCH V3 3/7] tty: serial: lpuart: add little endian 32 bit
 register support
Thread-Topic: [PATCH V3 3/7] tty: serial: lpuart: add little endian 32 bit
 register support
Thread-Index: AQHS45HOaIfNJRl5wk6tyL0S+0VD9KIiHX/g
Date: Tue, 13 Jun 2017 03:09:11 +0000
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From: Dong Aisheng <aisheng.dong@nxp.com> Sent: Monday, June 12, 2017 11:37 PM
>To: linux-serial@vger.kernel.org
>Cc: linux-kernel@vger.kernel.org; linux-arm-kernel@lists.infradead.org;
>gregkh@linuxfoundation.org; jslaby@suse.com; Andy Duan
><fugang.duan@nxp.com>; stefan@agner.ch; Mingkai Hu
><mingkai.hu@nxp.com>; Y.b. Lu <yangbo.lu@nxp.com>;
>nikita.yoush@cogentembedded.com; andy.shevchenko@gmail.com;
>dongas86@gmail.com; A.S. Dong <aisheng.dong@nxp.com>
>Subject: [PATCH V3 3/7] tty: serial: lpuart: add little endian 32 bit register
>support
>
>Use standard port->iotype to distinguish endian difference. Note as we
>read/write register by checking iotype dynamically, we need to initialize the
>iotype correctly for earlycon as well to avoid a break.
>
>Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>Cc: Jiri Slaby <jslaby@suse.com> (supporter:TTY LAYER)
>Cc: Stefan Agner <stefan@agner.ch>
>Cc: Mingkai Hu <Mingkai.Hu@nxp.com>
>Cc: Yangbo Lu <yangbo.lu@nxp.com>
>Cc: Fugang Duan <fugang.duan@nxp.com>
>Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
>
>ChangeLog:
>v2->v3:
> * Instead of using global var, use standard port->iotype to distinguish
>   endian difference.
>v1->v2:
> * No changes
>---
> drivers/tty/serial/fsl_lpuart.c | 43 +++++++++++++++++++++++++++----------
>----
> 1 file changed, 29 insertions(+), 14 deletions(-)
>
>diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index
>ed9db2f..bbf47a0 100644
>--- a/drivers/tty/serial/fsl_lpuart.c
>+++ b/drivers/tty/serial/fsl_lpuart.c
>@@ -280,15 +280,29 @@ MODULE_DEVICE_TABLE(of, lpuart_dt_ids);
> /* Forward declare this for the dma callbacks*/  static void
>lpuart_dma_tx_complete(void *arg);
>
>-static inline u32 lpuart32_read(struct uart_port *port, u32 reg_off) -{
>-	return ioread32be(port->membase + reg_off);
>+static inline u32 lpuart32_read(struct uart_port *port, u32 off) {
>+	switch (port->iotype) {
>+	case UPIO_MEM32:
>+		return readl(port->membase + off);
>+	case UPIO_MEM32BE:
>+		return ioread32be(port->membase + off);
>+	default:
>+		return 0;
>+	};
> }
>
> static inline void lpuart32_write(struct uart_port *port, u32 val,
>-				  u32 reg_off)
>+				  u32 off)
> {
>-	iowrite32be(val, port->membase + reg_off);
>+	switch (port->iotype) {
>+	case UPIO_MEM32:
>+		writel(val, port->membase + off);
>+		break;
>+	case UPIO_MEM32BE:
>+		iowrite32be(val, port->membase + off);
>+		break;
>+	};
> }
>
> static void lpuart_stop_tx(struct uart_port *port) @@ -602,7 +616,7 @@
>static irqreturn_t lpuart_txint(int irq, void *dev_id)
>
> 	spin_lock_irqsave(&sport->port.lock, flags);
> 	if (sport->port.x_char) {
>-		if (sport->port.iotype & UPIO_MEM32BE)
>+		if (sport->port.iotype & (UPIO_MEM32 | UPIO_MEM32BE))
> 			lpuart32_write(&sport->port, sport->port.x_char,
>UARTDATA);
> 		else
> 			writeb(sport->port.x_char, sport->port.membase +
>UARTDR); @@ -610,14 +624,14 @@ static irqreturn_t lpuart_txint(int irq, void
>*dev_id)
> 	}
>
> 	if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
>-		if (sport->port.iotype & UPIO_MEM32BE)
>+		if (sport->port.iotype & (UPIO_MEM32 | UPIO_MEM32BE))

Can use one macro instead of sport->port.iotype & (UPIO_MEM32 | UPIO_MEM32BE ?

> 			lpuart32_stop_tx(&sport->port);
> 		else
> 			lpuart_stop_tx(&sport->port);
> 		goto out;
> 	}
>
>-	if (sport->port.iotype & UPIO_MEM32BE)
>+	if (sport->port.iotype & (UPIO_MEM32 | UPIO_MEM32BE))
> 		lpuart32_transmit_buffer(sport);
> 	else
> 		lpuart_transmit_buffer(sport);
>@@ -1890,12 +1904,12 @@ static int __init lpuart_console_setup(struct
>console *co, char *options)
> 	if (options)
> 		uart_parse_options(options, &baud, &parity, &bits, &flow);
> 	else
>-		if (sport->port.iotype & UPIO_MEM32BE)
>+		if (sport->port.iotype & (UPIO_MEM32 | UPIO_MEM32BE))
> 			lpuart32_console_get_options(sport, &baud, &parity,
>&bits);
> 		else
> 			lpuart_console_get_options(sport, &baud, &parity,
>&bits);
>
>-	if (sport->port.iotype & UPIO_MEM32BE)
>+	if (sport->port.iotype & (UPIO_MEM32 | UPIO_MEM32BE))
> 		lpuart32_setup_watermark(sport);
> 	else
> 		lpuart_setup_watermark(sport);
>@@ -1954,6 +1968,7 @@ static int __init lpuart32_early_console_setup(struct
>earlycon_device *device,
> 	if (!device->port.membase)
> 		return -ENODEV;
>
>+	device->port.iotype = UPIO_MEM32BE;
> 	device->con->write = lpuart32_early_write;
> 	return 0;
> }
>@@ -2015,7 +2030,7 @@ static int lpuart_probe(struct platform_device *pdev)
> 	}
> 	sport->port.irq = ret;
> 	sport->port.iotype = sdata->iotype;
>-	if (sport->port.iotype & UPIO_MEM32BE)
>+	if (sport->port.iotype & (UPIO_MEM32 | UPIO_MEM32BE))
> 		sport->port.ops = &lpuart32_pops;
> 	else
> 		sport->port.ops = &lpuart_pops;
>@@ -2042,7 +2057,7 @@ static int lpuart_probe(struct platform_device *pdev)
>
> 	platform_set_drvdata(pdev, &sport->port);
>
>-	if (sport->port.iotype & UPIO_MEM32BE)
>+	if (sport->port.iotype & (UPIO_MEM32 | UPIO_MEM32BE))
> 		lpuart_reg.cons = LPUART32_CONSOLE;
> 	else
> 		lpuart_reg.cons = LPUART_CONSOLE;
>@@ -2095,7 +2110,7 @@ static int lpuart_suspend(struct device *dev)
> 	struct lpuart_port *sport = dev_get_drvdata(dev);
> 	unsigned long temp;
>
>-	if (sport->port.iotype & UPIO_MEM32BE) {
>+	if (sport->port.iotype & (UPIO_MEM32 | UPIO_MEM32BE)) {
> 		/* disable Rx/Tx and interrupts */
> 		temp = lpuart32_read(&sport->port, UARTCTRL);
> 		temp &= ~(UARTCTRL_TE | UARTCTRL_TIE | UARTCTRL_TCIE);
>@@ -2146,7 +2161,7 @@ static int lpuart_resume(struct device *dev)
> 	if (sport->port.suspended && !sport->port.irq_wake)
> 		clk_prepare_enable(sport->clk);
>
>-	if (sport->port.iotype & UPIO_MEM32BE) {
>+	if (sport->port.iotype & (UPIO_MEM32 | UPIO_MEM32BE)) {
> 		lpuart32_setup_watermark(sport);
> 		temp = lpuart32_read(&sport->port, UARTCTRL);
> 		temp |= (UARTCTRL_RIE | UARTCTRL_TIE | UARTCTRL_RE |
>--
>2.7.4