From b6e4913834cd032082e5c76dfade61050212dc98 Mon Sep 17 00:00:00 2001 From: Fabian Godehardt Date: Thu, 11 Jun 2009 14:53:18 +0100 Subject: [PATCH] imx: serial: add IrDA support to serial driver Using the iMX serial driver with an IrDA device needs extra peripheral settings and specific timing depending on the transmitter circuitry used. Signed-off-by: Fabian Godehardt Signed-off-by: Oskar Schirmer Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- arch/arm/plat-mxc/include/mach/imx-uart.h | 5 + drivers/serial/imx.c | 195 +++++++++++++++++++--- 2 files changed, 181 insertions(+), 19 deletions(-) diff --git a/arch/arm/plat-mxc/include/mach/imx-uart.h b/arch/arm/plat-mxc/include/mach/imx-uart.h index 599217b2e13f..f9bd17dd8dd7 100644 --- a/arch/arm/plat-mxc/include/mach/imx-uart.h +++ b/arch/arm/plat-mxc/include/mach/imx-uart.h @@ -20,11 +20,16 @@ #define ASMARM_ARCH_UART_H #define IMXUART_HAVE_RTSCTS (1<<0) +#define IMXUART_IRDA (1<<1) struct imxuart_platform_data { int (*init)(struct platform_device *pdev); int (*exit)(struct platform_device *pdev); unsigned int flags; + void (*irda_enable)(int enable); + unsigned int irda_inv_rx:1; + unsigned int irda_inv_tx:1; + unsigned short transceiver_delay; }; #endif diff --git a/drivers/serial/imx.c b/drivers/serial/imx.c index 0de81f71f884..8c79e8c2fd4e 100644 --- a/drivers/serial/imx.c +++ b/drivers/serial/imx.c @@ -8,6 +8,9 @@ * Author: Sascha Hauer * Copyright (C) 2004 Pengutronix * + * Copyright (C) 2009 emlix GmbH + * Author: Fabian Godehardt (added IrDA support for iMX) + * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or @@ -41,6 +44,7 @@ #include #include #include +#include #include #include @@ -149,6 +153,7 @@ #define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */ #define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */ #define UFCR_RFDIV (7<<7) /* Reference freq divider mask */ +#define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7) #define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */ #define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */ #define USR1_RTSS (1<<14) /* RTS pin status */ @@ -213,9 +218,19 @@ struct imx_port { unsigned int old_status; int txirq,rxirq,rtsirq; unsigned int have_rtscts:1; + unsigned int use_irda:1; + unsigned int irda_inv_rx:1; + unsigned int irda_inv_tx:1; + unsigned short trcv_delay; /* transceiver delay */ struct clk *clk; }; +#ifdef CONFIG_IRDA +#define USE_IRDA(sport) ((sport)->use_irda) +#else +#define USE_IRDA(sport) (0) +#endif + /* * Handle any change of modem status signal since we were last called. */ @@ -269,6 +284,48 @@ static void imx_stop_tx(struct uart_port *port) struct imx_port *sport = (struct imx_port *)port; unsigned long temp; + if (USE_IRDA(sport)) { + /* half duplex - wait for end of transmission */ + int n = 256; + while ((--n > 0) && + !(readl(sport->port.membase + USR2) & USR2_TXDC)) { + udelay(5); + barrier(); + } + /* + * irda transceiver - wait a bit more to avoid + * cutoff, hardware dependent + */ + udelay(sport->trcv_delay); + + /* + * half duplex - reactivate receive mode, + * flush receive pipe echo crap + */ + if (readl(sport->port.membase + USR2) & USR2_TXDC) { + temp = readl(sport->port.membase + UCR1); + temp &= ~(UCR1_TXMPTYEN | UCR1_TRDYEN); + writel(temp, sport->port.membase + UCR1); + + temp = readl(sport->port.membase + UCR4); + temp &= ~(UCR4_TCEN); + writel(temp, sport->port.membase + UCR4); + + while (readl(sport->port.membase + URXD0) & + URXD_CHARRDY) + barrier(); + + temp = readl(sport->port.membase + UCR1); + temp |= UCR1_RRDYEN; + writel(temp, sport->port.membase + UCR1); + + temp = readl(sport->port.membase + UCR4); + temp |= UCR4_DREN; + writel(temp, sport->port.membase + UCR4); + } + return; + } + temp = readl(sport->port.membase + UCR1); writel(temp & ~UCR1_TXMPTYEN, sport->port.membase + UCR1); } @@ -324,9 +381,30 @@ static void imx_start_tx(struct uart_port *port) struct imx_port *sport = (struct imx_port *)port; unsigned long temp; + if (USE_IRDA(sport)) { + /* half duplex in IrDA mode; have to disable receive mode */ + temp = readl(sport->port.membase + UCR4); + temp &= ~(UCR4_DREN); + writel(temp, sport->port.membase + UCR4); + + temp = readl(sport->port.membase + UCR1); + temp &= ~(UCR1_RRDYEN); + writel(temp, sport->port.membase + UCR1); + } + temp = readl(sport->port.membase + UCR1); writel(temp | UCR1_TXMPTYEN, sport->port.membase + UCR1); + if (USE_IRDA(sport)) { + temp = readl(sport->port.membase + UCR1); + temp |= UCR1_TRDYEN; + writel(temp, sport->port.membase + UCR1); + + temp = readl(sport->port.membase + UCR4); + temp |= UCR4_TCEN; + writel(temp, sport->port.membase + UCR4); + } + if (readl(sport->port.membase + UTS) & UTS_TXEMPTY) imx_transmit_buffer(sport); } @@ -536,12 +614,7 @@ static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode) if(!ufcr_rfdiv) ufcr_rfdiv = 1; - if(ufcr_rfdiv >= 7) - ufcr_rfdiv = 6; - else - ufcr_rfdiv = 6 - ufcr_rfdiv; - - val |= UFCR_RFDIV & (ufcr_rfdiv << 7); + val |= UFCR_RFDIV_REG(ufcr_rfdiv); writel(val, sport->port.membase + UFCR); @@ -560,8 +633,24 @@ static int imx_startup(struct uart_port *port) * requesting IRQs */ temp = readl(sport->port.membase + UCR4); + + if (USE_IRDA(sport)) + temp |= UCR4_IRSC; + writel(temp & ~UCR4_DREN, sport->port.membase + UCR4); + if (USE_IRDA(sport)) { + /* reset fifo's and state machines */ + int i = 100; + temp = readl(sport->port.membase + UCR2); + temp &= ~UCR2_SRST; + writel(temp, sport->port.membase + UCR2); + while (!(readl(sport->port.membase + UCR2) & UCR2_SRST) && + (--i > 0)) { + udelay(1); + } + } + /* * Allocate the IRQ(s) i.MX1 has three interrupts whereas later * chips only have one interrupt. @@ -577,12 +666,16 @@ static int imx_startup(struct uart_port *port) if (retval) goto error_out2; - retval = request_irq(sport->rtsirq, imx_rtsint, - (sport->rtsirq < MAX_INTERNAL_IRQ) ? 0 : - IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING, - DRIVER_NAME, sport); - if (retval) - goto error_out3; + /* do not use RTS IRQ on IrDA */ + if (!USE_IRDA(sport)) { + retval = request_irq(sport->rtsirq, imx_rtsint, + (sport->rtsirq < MAX_INTERNAL_IRQ) ? 0 : + IRQF_TRIGGER_FALLING | + IRQF_TRIGGER_RISING, + DRIVER_NAME, sport); + if (retval) + goto error_out3; + } } else { retval = request_irq(sport->port.irq, imx_int, 0, DRIVER_NAME, sport); @@ -599,18 +692,49 @@ static int imx_startup(struct uart_port *port) temp = readl(sport->port.membase + UCR1); temp |= UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN; + + if (USE_IRDA(sport)) { + temp |= UCR1_IREN; + temp &= ~(UCR1_RTSDEN); + } + writel(temp, sport->port.membase + UCR1); temp = readl(sport->port.membase + UCR2); temp |= (UCR2_RXEN | UCR2_TXEN); writel(temp, sport->port.membase + UCR2); + if (USE_IRDA(sport)) { + /* clear RX-FIFO */ + int i = 64; + while ((--i > 0) && + (readl(sport->port.membase + URXD0) & URXD_CHARRDY)) { + barrier(); + } + } + #if defined CONFIG_ARCH_MX2 || defined CONFIG_ARCH_MX3 temp = readl(sport->port.membase + UCR3); temp |= UCR3_RXDMUXSEL; writel(temp, sport->port.membase + UCR3); #endif + if (USE_IRDA(sport)) { + temp = readl(sport->port.membase + UCR4); + if (sport->irda_inv_rx) + temp |= UCR4_INVR; + else + temp &= ~(UCR4_INVR); + writel(temp | UCR4_DREN, sport->port.membase + UCR4); + + temp = readl(sport->port.membase + UCR3); + if (sport->irda_inv_tx) + temp |= UCR3_INVT; + else + temp &= ~(UCR3_INVT); + writel(temp, sport->port.membase + UCR3); + } + /* * Enable modem status interrupts */ @@ -618,6 +742,16 @@ static int imx_startup(struct uart_port *port) imx_enable_ms(&sport->port); spin_unlock_irqrestore(&sport->port.lock,flags); + if (USE_IRDA(sport)) { + struct imxuart_platform_data *pdata; + pdata = sport->port.dev->platform_data; + sport->irda_inv_rx = pdata->irda_inv_rx; + sport->irda_inv_tx = pdata->irda_inv_tx; + sport->trcv_delay = pdata->transceiver_delay; + if (pdata->irda_enable) + pdata->irda_enable(1); + } + return 0; error_out3: @@ -639,6 +773,13 @@ static void imx_shutdown(struct uart_port *port) temp &= ~(UCR2_TXEN); writel(temp, sport->port.membase + UCR2); + if (USE_IRDA(sport)) { + struct imxuart_platform_data *pdata; + pdata = sport->port.dev->platform_data; + if (pdata->irda_enable) + pdata->irda_enable(0); + } + /* * Stop our timer. */ @@ -648,7 +789,8 @@ static void imx_shutdown(struct uart_port *port) * Free the interrupts */ if (sport->txirq > 0) { - free_irq(sport->rtsirq, sport); + if (!USE_IRDA(sport)) + free_irq(sport->rtsirq, sport); free_irq(sport->txirq, sport); free_irq(sport->rxirq, sport); } else @@ -660,6 +802,9 @@ static void imx_shutdown(struct uart_port *port) temp = readl(sport->port.membase + UCR1); temp &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN); + if (USE_IRDA(sport)) + temp &= ~(UCR1_IREN); + writel(temp, sport->port.membase + UCR1); } @@ -768,11 +913,19 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios, sport->port.membase + UCR2); old_txrxen &= (UCR2_TXEN | UCR2_RXEN); - div = sport->port.uartclk / (baud * 16); - if (div > 7) - div = 7; - if (!div) + if (USE_IRDA(sport)) { + /* + * use maximum available submodule frequency to + * avoid missing short pulses due to low sampling rate + */ div = 1; + } else { + div = sport->port.uartclk / (baud * 16); + if (div > 7) + div = 7; + if (!div) + div = 1; + } rational_best_approximation(16 * div * baud, sport->port.uartclk, 1 << 16, 1 << 16, &num, &denom); @@ -781,8 +934,7 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios, denom -= 1; ufcr = readl(sport->port.membase + UFCR); - ufcr = (ufcr & (~UFCR_RFDIV)) | - (div << 7); + ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div); writel(ufcr, sport->port.membase + UFCR); writel(num, sport->port.membase + UBIR); @@ -1141,6 +1293,11 @@ static int serial_imx_probe(struct platform_device *pdev) if (pdata && (pdata->flags & IMXUART_HAVE_RTSCTS)) sport->have_rtscts = 1; +#ifdef CONFIG_IRDA + if (pdata && (pdata->flags & IMXUART_IRDA)) + sport->use_irda = 1; +#endif + if (pdata->init) { ret = pdata->init(pdev); if (ret) -- 2.34.1