diff mbox series

[v3,2/2] tty/serial: atmel: add ISO7816 support

Message ID 20180807130049.5957-3-ludovic.desroches@microchip.com (mailing list archive)
State New, archived
Headers show
Series add ISO7816 support | expand

Commit Message

Ludovic Desroches Aug. 7, 2018, 1 p.m. UTC 
From: Nicolas Ferre <nicolas.ferre@microchip.com>

When mode is set in atmel_config_iso7816() we backup last RS232 mode
for coming back to this mode if requested.
Also allow setup of T=0 and T=1 parameter and basic support in set_termios
function as well.

Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
[ludovic.desroches@microchip.com: rebase, add check on fidi ratio, checkpatch fixes]
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
---
 drivers/tty/serial/atmel_serial.c | 211 +++++++++++++++++++++++++++++++++++---
 drivers/tty/serial/atmel_serial.h |   6 +-
 2 files changed, 201 insertions(+), 16 deletions(-)

Comments

Richard Genoud Aug. 9, 2018, 8:47 a.m. UTC | #1 
Hi !

On 07/08/2018 15:00, Ludovic Desroches wrote:
> From: Nicolas Ferre <nicolas.ferre@microchip.com>
> 
> When mode is set in atmel_config_iso7816() we backup last RS232 mode
> for coming back to this mode if requested.
> Also allow setup of T=0 and T=1 parameter and basic support in set_termios
> function as well.
> 
> Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
> [ludovic.desroches@microchip.com: rebase, add check on fidi ratio, checkpatch fixes]
> Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
> ---
>  drivers/tty/serial/atmel_serial.c | 211 +++++++++++++++++++++++++++++++++++---
>  drivers/tty/serial/atmel_serial.h |   6 +-
>  2 files changed, 201 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 8e4428725848..4a7ec44b0ace 100644
> --- a/drivers/tty/serial/atmel_serial.c
> +++ b/drivers/tty/serial/atmel_serial.c
> @@ -34,6 +34,7 @@
>  #include <linux/suspend.h>
>  #include <linux/mm.h>
>  
> +#include <asm/div64.h>
>  #include <asm/io.h>
>  #include <asm/ioctls.h>
>  
> @@ -83,6 +84,11 @@ static void atmel_stop_rx(struct uart_port *port);
>  
>  #define ATMEL_ISR_PASS_LIMIT	256
>  
> +struct atmel_uart_pdata {
> +	unsigned int	fidi_min;
> +	unsigned int	fidi_max;
> +};
> +
>  struct atmel_dma_buffer {
>  	unsigned char	*buf;
>  	dma_addr_t	dma_addr;
> @@ -114,6 +120,7 @@ struct atmel_uart_char {
>   */
>  struct atmel_uart_port {
>  	struct uart_port	uart;		/* uart */
> +	const struct atmel_uart_pdata *pdata;	/* SoC specific parameters */
>  	struct clk		*clk;		/* uart clock */
>  	int			may_wakeup;	/* cached value of device_may_wakeup for times we need to disable it */
>  	u32			backup_imr;	/* IMR saved during suspend */
> @@ -147,6 +154,8 @@ struct atmel_uart_port {
>  	struct circ_buf		rx_ring;
>  
>  	struct mctrl_gpios	*gpios;
> +	u32			backup_mode;	/* MR saved during iso7816 operations */
> +	u32			backup_brgr;	/* BRGR saved during iso7816 operations */
>  	unsigned int		tx_done_mask;
>  	u32			fifo_size;
>  	u32			rts_high;
> @@ -192,10 +201,34 @@ static struct console atmel_console;
>  #endif
>  
>  #if defined(CONFIG_OF)
> +static struct atmel_uart_pdata at91rm9200_pdata = {
> +	.fidi_min = 1,
> +	.fidi_max = 2047,
> +};
> +
> +static struct atmel_uart_pdata at91sam9260_pdata = {
> +	.fidi_min = 1,
> +	.fidi_max = 2047,
> +};
> +
> +static struct atmel_uart_pdata sama5d3_pdata = {
> +	.fidi_min = 3,
> +	.fidi_max = 65535,
Are you sure this is for sama5d3 ?
From the datasheets I have, 65535 is for sama5d4/sama5d2
And also, you'll have to s/atmel,at91sam9260-usart/atmel,sama5d2-usart/g
in sama5d{2,4}.dtsi

But I wonder if it could be detected via ATMEL_US_VERSION instead ?


> +};
> +
>  static const struct of_device_id atmel_serial_dt_ids[] = {
> -	{ .compatible = "atmel,at91rm9200-usart" },
> -	{ .compatible = "atmel,at91sam9260-usart" },
> -	{ /* sentinel */ }
> +	{
> +		.compatible = "atmel,at91rm9200-usart",
> +		.data = &at91rm9200_pdata,
> +	}, {
> +		.compatible = "atmel,at91sam9260-usart",
> +		.data = &at91sam9260_pdata,
> +	}, {
> +		.compatible = "atmel,sama5d3-usart",
> +		.data = &sama5d3_pdata,
> +	}, {
> +		/* sentinel */
> +	}
>  };
>  #endif
>  
> @@ -362,6 +395,127 @@ static int atmel_config_rs485(struct uart_port *port,
>  	return 0;
>  }
>  
> +static unsigned int atmel_calc_cd(struct uart_port *port,
> +				  struct serial_iso7816 *iso7816conf)
> +{
> +	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> +	unsigned int cd;
> +	u64 mck_rate;
> +
> +	mck_rate = (u64)clk_get_rate(atmel_port->clk);
> +	do_div(mck_rate, iso7816conf->clk);
> +	cd = mck_rate;
> +	return cd;
> +}
> +
> +static unsigned int atmel_calc_fidi(struct uart_port *port,
> +				    struct serial_iso7816 *iso7816conf)
> +{
> +	u64 fidi = 0;
> +
> +	if (iso7816conf->sc_fi && iso7816conf->sc_di) {
> +		fidi = (u64)iso7816conf->sc_fi;
> +		do_div(fidi, iso7816conf->sc_di);
> +	}
> +	return (u32)fidi;
> +}
> +
> +/* Enable or disable the iso7816 support */
> +/* Called with interrupts disabled */
> +static int atmel_config_iso7816(struct uart_port *port,
> +				struct serial_iso7816 *iso7816conf)
> +{
> +	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
> +	unsigned int mode;
> +	unsigned int cd, fidi;
> +	int ret = 0;
> +
> +	/* Disable interrupts */
> +	atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);
> +
> +	mode = atmel_uart_readl(port, ATMEL_US_MR);
> +
> +	if (iso7816conf->flags & SER_ISO7816_ENABLED) {
> +		mode &= ~ATMEL_US_USMODE;
> +
> +		if (iso7816conf->tg > 255) {
> +			dev_err(port->dev, "ISO7816: Timeguard exceeding 255\n");
> +			memset(iso7816conf, 0, sizeof(struct serial_iso7816));
> +			ret = -EINVAL;
> +			goto err_out;
> +		}
> +
> +		if ((iso7816conf->flags & SER_ISO7816_T_PARAM)
> +		    == SER_ISO7816_T(0)) {
> +			mode |= ATMEL_US_USMODE_ISO7816_T0 | ATMEL_US_DSNACK;
> +		} else if ((iso7816conf->flags & SER_ISO7816_T_PARAM)
> +			   == SER_ISO7816_T(1)) {
> +			mode |= ATMEL_US_USMODE_ISO7816_T1 | ATMEL_US_INACK;
> +		} else {
> +			dev_err(port->dev, "ISO7816: Type not supported\n");
> +			memset(iso7816conf, 0, sizeof(struct serial_iso7816));
> +			ret = -EINVAL;
> +			goto err_out;
> +		}
> +
> +		mode &= ~(ATMEL_US_USCLKS | ATMEL_US_NBSTOP | ATMEL_US_PAR);
> +
> +		/* select mck clock, and output  */
> +		mode |= ATMEL_US_USCLKS_MCK | ATMEL_US_CLKO;
> +		/* set parity for normal/inverse mode + max iterations */
> +		mode |= ATMEL_US_PAR_EVEN | ATMEL_US_NBSTOP_1 | ATMEL_US_MAX_ITER(3);
> +
> +		cd = atmel_calc_cd(port, iso7816conf);
> +		fidi = atmel_calc_fidi(port, iso7816conf);
> +		if (fidi == 0) {
> +			dev_warn(port->dev, "ISO7816 fidi = 0, Generator generates no signal\n");
> +		} else if (fidi < atmel_port->pdata->fidi_min
> +			   || fidi > atmel_port->pdata->fidi_max) {
> +			dev_err(port->dev, "ISO7816 fidi = %u, value not supported\n", fidi);
> +			memset(iso7816conf, 0, sizeof(struct serial_iso7816));
> +			ret = -EINVAL;
> +			goto err_out;
> +		}
> +
> +		if (!(port->iso7816.flags & SER_ISO7816_ENABLED)) {
> +			/* port not yet in iso7816 mode: store configuration */
> +			atmel_port->backup_mode = atmel_uart_readl(port, ATMEL_US_MR);
> +			atmel_port->backup_brgr = atmel_uart_readl(port, ATMEL_US_BRGR);
> +		}
> +
> +		atmel_uart_writel(port, ATMEL_US_TTGR, iso7816conf->tg);
> +		atmel_uart_writel(port, ATMEL_US_BRGR, cd);
> +		atmel_uart_writel(port, ATMEL_US_FIDIR, fidi);
> +
> +		atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS | ATMEL_US_RXEN);
> +		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY | ATMEL_US_NACK | ATMEL_US_ITERATION;
> +	} else {
> +		dev_dbg(port->dev, "Setting UART back to RS232\n");
> +		/* back to last RS232 settings */
> +		mode = atmel_port->backup_mode;
> +		memset(iso7816conf, 0, sizeof(struct serial_iso7816));
> +		atmel_uart_writel(port, ATMEL_US_TTGR, 0);
> +		atmel_uart_writel(port, ATMEL_US_BRGR, atmel_port->backup_brgr);
> +		atmel_uart_writel(port, ATMEL_US_FIDIR, 0x174);
> +
> +		if (atmel_use_pdc_tx(port))
> +			atmel_port->tx_done_mask = ATMEL_US_ENDTX |
> +						   ATMEL_US_TXBUFE;
> +		else
> +			atmel_port->tx_done_mask = ATMEL_US_TXRDY;
> +	}
> +
> +	port->iso7816 = *iso7816conf;
> +
> +	atmel_uart_writel(port, ATMEL_US_MR, mode);
> +
> +err_out:
> +	/* Enable interrupts */
> +	atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask);
> +
> +	return ret;
> +}
> +
>  /*
>   * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
>   */
> @@ -481,8 +635,9 @@ static void atmel_stop_tx(struct uart_port *port)
>  	/* Disable interrupts */
>  	atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);
>  
> -	if ((port->rs485.flags & SER_RS485_ENABLED) &&
> -	    !(port->rs485.flags & SER_RS485_RX_DURING_TX))
> +	if (((port->rs485.flags & SER_RS485_ENABLED) &&
> +	     !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
> +	    port->iso7816.flags & SER_ISO7816_ENABLED)
>  		atmel_start_rx(port);
>  }
>  
> @@ -500,8 +655,9 @@ static void atmel_start_tx(struct uart_port *port)
>  		return;
>  
>  	if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port))
> -		if ((port->rs485.flags & SER_RS485_ENABLED) &&
> -		    !(port->rs485.flags & SER_RS485_RX_DURING_TX))
> +		if (((port->rs485.flags & SER_RS485_ENABLED) &&
> +		     !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
> +		    port->iso7816.flags & SER_ISO7816_ENABLED)
>  			atmel_stop_rx(port);
>  
>  	if (atmel_use_pdc_tx(port))
> @@ -799,8 +955,9 @@ static void atmel_complete_tx_dma(void *arg)
>  	 */
>  	if (!uart_circ_empty(xmit))
>  		atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx);
> -	else if ((port->rs485.flags & SER_RS485_ENABLED) &&
> -		 !(port->rs485.flags & SER_RS485_RX_DURING_TX)) {
> +	else if (((port->rs485.flags & SER_RS485_ENABLED) &&
> +		  !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
> +		 port->iso7816.flags & SER_ISO7816_ENABLED) {
>  		/* DMA done, stop TX, start RX for RS485 */
>  		atmel_start_rx(port);
>  	}
> @@ -1281,6 +1438,9 @@ atmel_handle_status(struct uart_port *port, unsigned int pending,
>  			wake_up_interruptible(&port->state->port.delta_msr_wait);
>  		}
>  	}
> +
> +	if (pending & (ATMEL_US_NACK | ATMEL_US_ITERATION))
> +		dev_dbg(port->dev, "ISO7816 ERROR (0x%08x)\n", pending);
>  }
>  
>  /*
> @@ -1373,8 +1533,9 @@ static void atmel_tx_pdc(struct uart_port *port)
>  		atmel_uart_writel(port, ATMEL_US_IER,
>  				  atmel_port->tx_done_mask);
>  	} else {
> -		if ((port->rs485.flags & SER_RS485_ENABLED) &&
> -		    !(port->rs485.flags & SER_RS485_RX_DURING_TX)) {
> +		if (((port->rs485.flags & SER_RS485_ENABLED) &&
> +		     !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
> +		    port->iso7816.flags & SER_ISO7816_ENABLED) {
>  			/* DMA done, stop TX, start RX for RS485 */
>  			atmel_start_rx(port);
>  		}
> @@ -2099,6 +2260,17 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
>  		atmel_uart_writel(port, ATMEL_US_TTGR,
>  				  port->rs485.delay_rts_after_send);
>  		mode |= ATMEL_US_USMODE_RS485;
> +	} else if (port->iso7816.flags & SER_ISO7816_ENABLED) {
> +		atmel_uart_writel(port, ATMEL_US_TTGR, port->iso7816.tg);
> +		/* select mck clock, and output  */
> +		mode |= ATMEL_US_USCLKS_MCK | ATMEL_US_CLKO;
> +		/* set max iterations */
> +		mode |= ATMEL_US_MAX_ITER(3);
> +		if ((port->iso7816.flags & SER_ISO7816_T_PARAM)
> +				== SER_ISO7816_T(0))
> +			mode |= ATMEL_US_USMODE_ISO7816_T0;
> +		else
> +			mode |= ATMEL_US_USMODE_ISO7816_T1;
>  	} else if (termios->c_cflag & CRTSCTS) {
>  		/* RS232 with hardware handshake (RTS/CTS) */
>  		if (atmel_use_fifo(port) &&
> @@ -2175,7 +2347,8 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
>  	}
>  	quot = cd | fp << ATMEL_US_FP_OFFSET;
>  
> -	atmel_uart_writel(port, ATMEL_US_BRGR, quot);
> +	if (!(port->iso7816.flags & SER_ISO7816_ENABLED))
> +		atmel_uart_writel(port, ATMEL_US_BRGR, quot);
>  	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
>  	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);
>  	atmel_port->tx_stopped = false;
> @@ -2355,6 +2528,7 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
>  	port->mapbase	= pdev->resource[0].start;
>  	port->irq	= pdev->resource[1].start;
>  	port->rs485_config	= atmel_config_rs485;
> +	port->iso7816_config	= atmel_config_iso7816;
>  	port->membase	= NULL;
>  
>  	memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
> @@ -2378,8 +2552,12 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port,
>  		/* only enable clock when USART is in use */
>  	}
>  
> -	/* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
> -	if (port->rs485.flags & SER_RS485_ENABLED)
> +	/*
> +	 * Use TXEMPTY for interrupt when rs485 or ISO7816 else TXRDY or
> +	 * ENDTX|TXBUFE
> +	 */
> +	if (port->rs485.flags & SER_RS485_ENABLED ||
> +	    port->iso7816.flags & SER_ISO7816_ENABLED)
>  		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
>  	else if (atmel_use_pdc_tx(port)) {
>  		port->fifosize = PDC_BUFFER_SIZE;
> @@ -2719,6 +2897,11 @@ static int atmel_serial_probe(struct platform_device *pdev)
>  	}
>  
>  	atmel_port = &atmel_ports[ret];
> +	atmel_port->pdata = of_device_get_match_data(&pdev->dev);
> +	if (!atmel_port->pdata) {
> +		ret = -EINVAL;
> +		goto err;
> +	}
>  	atmel_port->backup_imr = 0;
>  	atmel_port->uart.line = ret;
>  	atmel_serial_probe_fifos(atmel_port, pdev);
> diff --git a/drivers/tty/serial/atmel_serial.h b/drivers/tty/serial/atmel_serial.h
> index ba3a2437cde4..6911177964ad 100644
> --- a/drivers/tty/serial/atmel_serial.h
> +++ b/drivers/tty/serial/atmel_serial.h
> @@ -78,7 +78,8 @@
>  #define	ATMEL_US_OVER		BIT(19)	/* Oversampling Mode */
>  #define	ATMEL_US_INACK		BIT(20)	/* Inhibit Non Acknowledge */
>  #define	ATMEL_US_DSNACK		BIT(21)	/* Disable Successive NACK */
> -#define	ATMEL_US_MAX_ITER	GENMASK(26, 24)	/* Max Iterations */
> +#define	ATMEL_US_MAX_ITER_MASK	GENMASK(26, 24)	/* Max Iterations */
> +#define	ATMEL_US_MAX_ITER(n)	(((n) << 24) & ATMEL_US_MAX_ITER_MASK)
>  #define	ATMEL_US_FILTER		BIT(28)	/* Infrared Receive Line Filter */
>  
>  #define ATMEL_US_IER		0x08	/* Interrupt Enable Register */
> @@ -124,7 +125,8 @@
>  #define ATMEL_US_TTGR		0x28	/* Transmitter Timeguard Register */
>  #define	ATMEL_US_TG		GENMASK(7, 0)	/* Timeguard Value */
>  
> -#define ATMEL_US_FIDI		0x40	/* FI DI Ratio Register */
> +#define ATMEL_US_FIDIR		0x40	/* FI DI Ratio Register */
> +#define ATMEL_US_FIDI		GENMASK(15, 0)	/* FIDI ratio */
>  #define ATMEL_US_NER		0x44	/* Number of Errors Register */
>  #define ATMEL_US_IF		0x4c	/* IrDA Filter Register */
>  
> 
Thanks !
Ludovic Desroches Aug. 9, 2018, 11:30 a.m. UTC | #2 
Hi Richard,

On Thu, Aug 09, 2018 at 10:47:17AM +0200, Richard Genoud wrote:
> Hi !
> 
> On 07/08/2018 15:00, Ludovic Desroches wrote:
> > From: Nicolas Ferre <nicolas.ferre@microchip.com>
> > 
> > When mode is set in atmel_config_iso7816() we backup last RS232 mode
> > for coming back to this mode if requested.
> > Also allow setup of T=0 and T=1 parameter and basic support in set_termios
> > function as well.
> > 
> > Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
> > [ludovic.desroches@microchip.com: rebase, add check on fidi ratio, checkpatch fixes]
> > Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
> > ---
> >  drivers/tty/serial/atmel_serial.c | 211 +++++++++++++++++++++++++++++++++++---
> >  drivers/tty/serial/atmel_serial.h |   6 +-
> >  2 files changed, 201 insertions(+), 16 deletions(-)
> > 
> > diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> > index 8e4428725848..4a7ec44b0ace 100644
> > --- a/drivers/tty/serial/atmel_serial.c
> > +++ b/drivers/tty/serial/atmel_serial.c

[...]

> >  #if defined(CONFIG_OF)
> > +static struct atmel_uart_pdata at91rm9200_pdata = {
> > +	.fidi_min = 1,
> > +	.fidi_max = 2047,
> > +};
> > +
> > +static struct atmel_uart_pdata at91sam9260_pdata = {
> > +	.fidi_min = 1,
> > +	.fidi_max = 2047,
> > +};
> > +
> > +static struct atmel_uart_pdata sama5d3_pdata = {
> > +	.fidi_min = 3,
> > +	.fidi_max = 65535,
> Are you sure this is for sama5d3 ?
> From the datasheets I have, 65535 is for sama5d4/sama5d2

I checked it and I missed it. What a pity... In fact, it's a bit more
tricky since the min value for d3 is 3 and no longer 1.

> And also, you'll have to s/atmel,at91sam9260-usart/atmel,sama5d2-usart/g
> in sama5d{2,4}.dtsi
>

Yes, I planed to send it later but I can add those patches within this
set of patches. 

> But I wonder if it could be detected via ATMEL_US_VERSION instead ?
> 

I have not checked, I tend to prefer the compatible string for this kind
of thing. But as we already use the version number, I can investigate
this solution if it's the one you prefer.


Regards

Ludovic
Ludovic Desroches Sept. 5, 2018, 12:43 p.m. UTC | #3 
Hi Richard,

On Thu, Aug 09, 2018 at 01:30:35PM +0200, Ludovic Desroches wrote:
> Hi Richard,
> 
> On Thu, Aug 09, 2018 at 10:47:17AM +0200, Richard Genoud wrote:
> > Hi !
> > 
> > On 07/08/2018 15:00, Ludovic Desroches wrote:
> > > From: Nicolas Ferre <nicolas.ferre@microchip.com>
> > > 
> > > When mode is set in atmel_config_iso7816() we backup last RS232 mode
> > > for coming back to this mode if requested.
> > > Also allow setup of T=0 and T=1 parameter and basic support in set_termios
> > > function as well.
> > > 
> > > Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
> > > [ludovic.desroches@microchip.com: rebase, add check on fidi ratio, checkpatch fixes]
> > > Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
> > > ---
> > >  drivers/tty/serial/atmel_serial.c | 211 +++++++++++++++++++++++++++++++++++---
> > >  drivers/tty/serial/atmel_serial.h |   6 +-
> > >  2 files changed, 201 insertions(+), 16 deletions(-)
> > > 
> > > diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> > > index 8e4428725848..4a7ec44b0ace 100644
> > > --- a/drivers/tty/serial/atmel_serial.c
> > > +++ b/drivers/tty/serial/atmel_serial.c
> 
> [...]
> 
> > >  #if defined(CONFIG_OF)
> > > +static struct atmel_uart_pdata at91rm9200_pdata = {
> > > +	.fidi_min = 1,
> > > +	.fidi_max = 2047,
> > > +};
> > > +
> > > +static struct atmel_uart_pdata at91sam9260_pdata = {
> > > +	.fidi_min = 1,
> > > +	.fidi_max = 2047,
> > > +};
> > > +
> > > +static struct atmel_uart_pdata sama5d3_pdata = {
> > > +	.fidi_min = 3,
> > > +	.fidi_max = 65535,
> > Are you sure this is for sama5d3 ?
> > From the datasheets I have, 65535 is for sama5d4/sama5d2
> 
> I checked it and I missed it. What a pity... In fact, it's a bit more
> tricky since the min value for d3 is 3 and no longer 1.
> 
> > And also, you'll have to s/atmel,at91sam9260-usart/atmel,sama5d2-usart/g
> > in sama5d{2,4}.dtsi
> >
> 
> Yes, I planed to send it later but I can add those patches within this
> set of patches. 
> 
> > But I wonder if it could be detected via ATMEL_US_VERSION instead ?
> > 
> 
> I have not checked, I tend to prefer the compatible string for this kind
> of thing. But as we already use the version number, I can investigate
> this solution if it's the one you prefer.
> 

ping about this question still in suspend in order to prepare a new version.

Regards

Ludovic
Richard Genoud Sept. 5, 2018, 1:53 p.m. UTC | #4 
[added Nicolas back in the thread, he was removed somehow]

Hi Ludovic !

On 05/09/2018 14:43, Ludovic Desroches wrote:
> Hi Richard,
> 
> On Thu, Aug 09, 2018 at 01:30:35PM +0200, Ludovic Desroches wrote:
>> Hi Richard,
>>
>> On Thu, Aug 09, 2018 at 10:47:17AM +0200, Richard Genoud wrote:
>>> Hi !
>>>
>>> On 07/08/2018 15:00, Ludovic Desroches wrote:
>>>> From: Nicolas Ferre <nicolas.ferre@microchip.com>
>>>>
>>>> When mode is set in atmel_config_iso7816() we backup last RS232 mode
>>>> for coming back to this mode if requested.
>>>> Also allow setup of T=0 and T=1 parameter and basic support in set_termios
>>>> function as well.
>>>>
>>>> Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
>>>> [ludovic.desroches@microchip.com: rebase, add check on fidi ratio, checkpatch fixes]
>>>> Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
>>>> ---
>>>>  drivers/tty/serial/atmel_serial.c | 211 +++++++++++++++++++++++++++++++++++---
>>>>  drivers/tty/serial/atmel_serial.h |   6 +-
>>>>  2 files changed, 201 insertions(+), 16 deletions(-)
>>>>
>>>> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
>>>> index 8e4428725848..4a7ec44b0ace 100644
>>>> --- a/drivers/tty/serial/atmel_serial.c
>>>> +++ b/drivers/tty/serial/atmel_serial.c
>>
>> [...]
>>
>>>>  #if defined(CONFIG_OF)
>>>> +static struct atmel_uart_pdata at91rm9200_pdata = {
>>>> +	.fidi_min = 1,
>>>> +	.fidi_max = 2047,
>>>> +};
>>>> +
>>>> +static struct atmel_uart_pdata at91sam9260_pdata = {
>>>> +	.fidi_min = 1,
>>>> +	.fidi_max = 2047,
>>>> +};
>>>> +
>>>> +static struct atmel_uart_pdata sama5d3_pdata = {
>>>> +	.fidi_min = 3,
>>>> +	.fidi_max = 65535,
>>> Are you sure this is for sama5d3 ?
>>> From the datasheets I have, 65535 is for sama5d4/sama5d2
>>
>> I checked it and I missed it. What a pity... In fact, it's a bit more
>> tricky since the min value for d3 is 3 and no longer 1.
>>
>>> And also, you'll have to s/atmel,at91sam9260-usart/atmel,sama5d2-usart/g
>>> in sama5d{2,4}.dtsi
>>>
>>
>> Yes, I planed to send it later but I can add those patches within this
>> set of patches. 
>>
>>> But I wonder if it could be detected via ATMEL_US_VERSION instead ?
>>>
>>
>> I have not checked, I tend to prefer the compatible string for this kind
>> of thing. But as we already use the version number, I can investigate
>> this solution if it's the one you prefer.
>>
> 
> ping about this question still in suspend in order to prepare a new version.
Well, if we use the compatible string for this, we will have to add :
- atmel,sama5d2-usart
- atmel,sama5d3-usart
- (maybe others ?)
to the already existing :
- atmel,at91sam9260-usart
- atmel,at91rm9200-usart
just for setting different limits on the fidi register.
IMHO, it seems a bit overkill. Moreover, the ATMEL_US_VERSION has
already been read, so...
But if you think adding compatible strings is a better/cleaner solution, just convince me ! :)
Ludovic Desroches Sept. 5, 2018, 2:14 p.m. UTC | #5 
On Wed, Sep 05, 2018 at 03:53:02PM +0200, Richard Genoud wrote:
> [added Nicolas back in the thread, he was removed somehow]
> 
> Hi Ludovic !
> 
> On 05/09/2018 14:43, Ludovic Desroches wrote:
> > Hi Richard,
> > 
> > On Thu, Aug 09, 2018 at 01:30:35PM +0200, Ludovic Desroches wrote:
> >> Hi Richard,
> >>
> >> On Thu, Aug 09, 2018 at 10:47:17AM +0200, Richard Genoud wrote:
> >>> Hi !
> >>>
> >>> On 07/08/2018 15:00, Ludovic Desroches wrote:
> >>>> From: Nicolas Ferre <nicolas.ferre@microchip.com>
> >>>>
> >>>> When mode is set in atmel_config_iso7816() we backup last RS232 mode
> >>>> for coming back to this mode if requested.
> >>>> Also allow setup of T=0 and T=1 parameter and basic support in set_termios
> >>>> function as well.
> >>>>
> >>>> Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
> >>>> [ludovic.desroches@microchip.com: rebase, add check on fidi ratio, checkpatch fixes]
> >>>> Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
> >>>> ---
> >>>>  drivers/tty/serial/atmel_serial.c | 211 +++++++++++++++++++++++++++++++++++---
> >>>>  drivers/tty/serial/atmel_serial.h |   6 +-
> >>>>  2 files changed, 201 insertions(+), 16 deletions(-)
> >>>>
> >>>> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> >>>> index 8e4428725848..4a7ec44b0ace 100644
> >>>> --- a/drivers/tty/serial/atmel_serial.c
> >>>> +++ b/drivers/tty/serial/atmel_serial.c
> >>
> >> [...]
> >>
> >>>>  #if defined(CONFIG_OF)
> >>>> +static struct atmel_uart_pdata at91rm9200_pdata = {
> >>>> +	.fidi_min = 1,
> >>>> +	.fidi_max = 2047,
> >>>> +};
> >>>> +
> >>>> +static struct atmel_uart_pdata at91sam9260_pdata = {
> >>>> +	.fidi_min = 1,
> >>>> +	.fidi_max = 2047,
> >>>> +};
> >>>> +
> >>>> +static struct atmel_uart_pdata sama5d3_pdata = {
> >>>> +	.fidi_min = 3,
> >>>> +	.fidi_max = 65535,
> >>> Are you sure this is for sama5d3 ?
> >>> From the datasheets I have, 65535 is for sama5d4/sama5d2
> >>
> >> I checked it and I missed it. What a pity... In fact, it's a bit more
> >> tricky since the min value for d3 is 3 and no longer 1.
> >>
> >>> And also, you'll have to s/atmel,at91sam9260-usart/atmel,sama5d2-usart/g
> >>> in sama5d{2,4}.dtsi
> >>>
> >>
> >> Yes, I planed to send it later but I can add those patches within this
> >> set of patches. 
> >>
> >>> But I wonder if it could be detected via ATMEL_US_VERSION instead ?
> >>>
> >>
> >> I have not checked, I tend to prefer the compatible string for this kind
> >> of thing. But as we already use the version number, I can investigate
> >> this solution if it's the one you prefer.
> >>
> > 
> > ping about this question still in suspend in order to prepare a new version.
> Well, if we use the compatible string for this, we will have to add :
> - atmel,sama5d2-usart
> - atmel,sama5d3-usart
> - (maybe others ?)
> to the already existing :
> - atmel,at91sam9260-usart
> - atmel,at91rm9200-usart
> just for setting different limits on the fidi register.
> IMHO, it seems a bit overkill. Moreover, the ATMEL_US_VERSION has
> already been read, so...
> But if you think adding compatible strings is a better/cleaner solution, just convince me ! :)

I won't try to convince you since we already use the ATMEL_US_VERSION.
IMHO we should use the compatible string from the beginning but we
didn't have the necessary DT experience at this time to figure out it
was probably better than relying on the version number which can be not
incrimented by error.

I'll check the values of the ATMEL_US_VERSION and use it if everything
is okay.

Regards

Ludovic
diff mbox series

Patch

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 8e4428725848..4a7ec44b0ace 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -34,6 +34,7 @@ 
 #include <linux/suspend.h>
 #include <linux/mm.h>
 
+#include <asm/div64.h>
 #include <asm/io.h>
 #include <asm/ioctls.h>
 
@@ -83,6 +84,11 @@  static void atmel_stop_rx(struct uart_port *port);
 
 #define ATMEL_ISR_PASS_LIMIT	256
 
+struct atmel_uart_pdata {
+	unsigned int	fidi_min;
+	unsigned int	fidi_max;
+};
+
 struct atmel_dma_buffer {
 	unsigned char	*buf;
 	dma_addr_t	dma_addr;
@@ -114,6 +120,7 @@  struct atmel_uart_char {
  */
 struct atmel_uart_port {
 	struct uart_port	uart;		/* uart */
+	const struct atmel_uart_pdata *pdata;	/* SoC specific parameters */
 	struct clk		*clk;		/* uart clock */
 	int			may_wakeup;	/* cached value of device_may_wakeup for times we need to disable it */
 	u32			backup_imr;	/* IMR saved during suspend */
@@ -147,6 +154,8 @@  struct atmel_uart_port {
 	struct circ_buf		rx_ring;
 
 	struct mctrl_gpios	*gpios;
+	u32			backup_mode;	/* MR saved during iso7816 operations */
+	u32			backup_brgr;	/* BRGR saved during iso7816 operations */
 	unsigned int		tx_done_mask;
 	u32			fifo_size;
 	u32			rts_high;
@@ -192,10 +201,34 @@  static struct console atmel_console;
 #endif
 
 #if defined(CONFIG_OF)
+static struct atmel_uart_pdata at91rm9200_pdata = {
+	.fidi_min = 1,
+	.fidi_max = 2047,
+};
+
+static struct atmel_uart_pdata at91sam9260_pdata = {
+	.fidi_min = 1,
+	.fidi_max = 2047,
+};
+
+static struct atmel_uart_pdata sama5d3_pdata = {
+	.fidi_min = 3,
+	.fidi_max = 65535,
+};
+
 static const struct of_device_id atmel_serial_dt_ids[] = {
-	{ .compatible = "atmel,at91rm9200-usart" },
-	{ .compatible = "atmel,at91sam9260-usart" },
-	{ /* sentinel */ }
+	{
+		.compatible = "atmel,at91rm9200-usart",
+		.data = &at91rm9200_pdata,
+	}, {
+		.compatible = "atmel,at91sam9260-usart",
+		.data = &at91sam9260_pdata,
+	}, {
+		.compatible = "atmel,sama5d3-usart",
+		.data = &sama5d3_pdata,
+	}, {
+		/* sentinel */
+	}
 };
 #endif
 
@@ -362,6 +395,127 @@  static int atmel_config_rs485(struct uart_port *port,
 	return 0;
 }
 
+static unsigned int atmel_calc_cd(struct uart_port *port,
+				  struct serial_iso7816 *iso7816conf)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned int cd;
+	u64 mck_rate;
+
+	mck_rate = (u64)clk_get_rate(atmel_port->clk);
+	do_div(mck_rate, iso7816conf->clk);
+	cd = mck_rate;
+	return cd;
+}
+
+static unsigned int atmel_calc_fidi(struct uart_port *port,
+				    struct serial_iso7816 *iso7816conf)
+{
+	u64 fidi = 0;
+
+	if (iso7816conf->sc_fi && iso7816conf->sc_di) {
+		fidi = (u64)iso7816conf->sc_fi;
+		do_div(fidi, iso7816conf->sc_di);
+	}
+	return (u32)fidi;
+}
+
+/* Enable or disable the iso7816 support */
+/* Called with interrupts disabled */
+static int atmel_config_iso7816(struct uart_port *port,
+				struct serial_iso7816 *iso7816conf)
+{
+	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+	unsigned int mode;
+	unsigned int cd, fidi;
+	int ret = 0;
+
+	/* Disable interrupts */
+	atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);
+
+	mode = atmel_uart_readl(port, ATMEL_US_MR);
+
+	if (iso7816conf->flags & SER_ISO7816_ENABLED) {
+		mode &= ~ATMEL_US_USMODE;
+
+		if (iso7816conf->tg > 255) {
+			dev_err(port->dev, "ISO7816: Timeguard exceeding 255\n");
+			memset(iso7816conf, 0, sizeof(struct serial_iso7816));
+			ret = -EINVAL;
+			goto err_out;
+		}
+
+		if ((iso7816conf->flags & SER_ISO7816_T_PARAM)
+		    == SER_ISO7816_T(0)) {
+			mode |= ATMEL_US_USMODE_ISO7816_T0 | ATMEL_US_DSNACK;
+		} else if ((iso7816conf->flags & SER_ISO7816_T_PARAM)
+			   == SER_ISO7816_T(1)) {
+			mode |= ATMEL_US_USMODE_ISO7816_T1 | ATMEL_US_INACK;
+		} else {
+			dev_err(port->dev, "ISO7816: Type not supported\n");
+			memset(iso7816conf, 0, sizeof(struct serial_iso7816));
+			ret = -EINVAL;
+			goto err_out;
+		}
+
+		mode &= ~(ATMEL_US_USCLKS | ATMEL_US_NBSTOP | ATMEL_US_PAR);
+
+		/* select mck clock, and output  */
+		mode |= ATMEL_US_USCLKS_MCK | ATMEL_US_CLKO;
+		/* set parity for normal/inverse mode + max iterations */
+		mode |= ATMEL_US_PAR_EVEN | ATMEL_US_NBSTOP_1 | ATMEL_US_MAX_ITER(3);
+
+		cd = atmel_calc_cd(port, iso7816conf);
+		fidi = atmel_calc_fidi(port, iso7816conf);
+		if (fidi == 0) {
+			dev_warn(port->dev, "ISO7816 fidi = 0, Generator generates no signal\n");
+		} else if (fidi < atmel_port->pdata->fidi_min
+			   || fidi > atmel_port->pdata->fidi_max) {
+			dev_err(port->dev, "ISO7816 fidi = %u, value not supported\n", fidi);
+			memset(iso7816conf, 0, sizeof(struct serial_iso7816));
+			ret = -EINVAL;
+			goto err_out;
+		}
+
+		if (!(port->iso7816.flags & SER_ISO7816_ENABLED)) {
+			/* port not yet in iso7816 mode: store configuration */
+			atmel_port->backup_mode = atmel_uart_readl(port, ATMEL_US_MR);
+			atmel_port->backup_brgr = atmel_uart_readl(port, ATMEL_US_BRGR);
+		}
+
+		atmel_uart_writel(port, ATMEL_US_TTGR, iso7816conf->tg);
+		atmel_uart_writel(port, ATMEL_US_BRGR, cd);
+		atmel_uart_writel(port, ATMEL_US_FIDIR, fidi);
+
+		atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXDIS | ATMEL_US_RXEN);
+		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY | ATMEL_US_NACK | ATMEL_US_ITERATION;
+	} else {
+		dev_dbg(port->dev, "Setting UART back to RS232\n");
+		/* back to last RS232 settings */
+		mode = atmel_port->backup_mode;
+		memset(iso7816conf, 0, sizeof(struct serial_iso7816));
+		atmel_uart_writel(port, ATMEL_US_TTGR, 0);
+		atmel_uart_writel(port, ATMEL_US_BRGR, atmel_port->backup_brgr);
+		atmel_uart_writel(port, ATMEL_US_FIDIR, 0x174);
+
+		if (atmel_use_pdc_tx(port))
+			atmel_port->tx_done_mask = ATMEL_US_ENDTX |
+						   ATMEL_US_TXBUFE;
+		else
+			atmel_port->tx_done_mask = ATMEL_US_TXRDY;
+	}
+
+	port->iso7816 = *iso7816conf;
+
+	atmel_uart_writel(port, ATMEL_US_MR, mode);
+
+err_out:
+	/* Enable interrupts */
+	atmel_uart_writel(port, ATMEL_US_IER, atmel_port->tx_done_mask);
+
+	return ret;
+}
+
 /*
  * Return TIOCSER_TEMT when transmitter FIFO and Shift register is empty.
  */
@@ -481,8 +635,9 @@  static void atmel_stop_tx(struct uart_port *port)
 	/* Disable interrupts */
 	atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);
 
-	if ((port->rs485.flags & SER_RS485_ENABLED) &&
-	    !(port->rs485.flags & SER_RS485_RX_DURING_TX))
+	if (((port->rs485.flags & SER_RS485_ENABLED) &&
+	     !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
+	    port->iso7816.flags & SER_ISO7816_ENABLED)
 		atmel_start_rx(port);
 }
 
@@ -500,8 +655,9 @@  static void atmel_start_tx(struct uart_port *port)
 		return;
 
 	if (atmel_use_pdc_tx(port) || atmel_use_dma_tx(port))
-		if ((port->rs485.flags & SER_RS485_ENABLED) &&
-		    !(port->rs485.flags & SER_RS485_RX_DURING_TX))
+		if (((port->rs485.flags & SER_RS485_ENABLED) &&
+		     !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
+		    port->iso7816.flags & SER_ISO7816_ENABLED)
 			atmel_stop_rx(port);
 
 	if (atmel_use_pdc_tx(port))
@@ -799,8 +955,9 @@  static void atmel_complete_tx_dma(void *arg)
 	 */
 	if (!uart_circ_empty(xmit))
 		atmel_tasklet_schedule(atmel_port, &atmel_port->tasklet_tx);
-	else if ((port->rs485.flags & SER_RS485_ENABLED) &&
-		 !(port->rs485.flags & SER_RS485_RX_DURING_TX)) {
+	else if (((port->rs485.flags & SER_RS485_ENABLED) &&
+		  !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
+		 port->iso7816.flags & SER_ISO7816_ENABLED) {
 		/* DMA done, stop TX, start RX for RS485 */
 		atmel_start_rx(port);
 	}
@@ -1281,6 +1438,9 @@  atmel_handle_status(struct uart_port *port, unsigned int pending,
 			wake_up_interruptible(&port->state->port.delta_msr_wait);
 		}
 	}
+
+	if (pending & (ATMEL_US_NACK | ATMEL_US_ITERATION))
+		dev_dbg(port->dev, "ISO7816 ERROR (0x%08x)\n", pending);
 }
 
 /*
@@ -1373,8 +1533,9 @@  static void atmel_tx_pdc(struct uart_port *port)
 		atmel_uart_writel(port, ATMEL_US_IER,
 				  atmel_port->tx_done_mask);
 	} else {
-		if ((port->rs485.flags & SER_RS485_ENABLED) &&
-		    !(port->rs485.flags & SER_RS485_RX_DURING_TX)) {
+		if (((port->rs485.flags & SER_RS485_ENABLED) &&
+		     !(port->rs485.flags & SER_RS485_RX_DURING_TX)) ||
+		    port->iso7816.flags & SER_ISO7816_ENABLED) {
 			/* DMA done, stop TX, start RX for RS485 */
 			atmel_start_rx(port);
 		}
@@ -2099,6 +2260,17 @@  static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
 		atmel_uart_writel(port, ATMEL_US_TTGR,
 				  port->rs485.delay_rts_after_send);
 		mode |= ATMEL_US_USMODE_RS485;
+	} else if (port->iso7816.flags & SER_ISO7816_ENABLED) {
+		atmel_uart_writel(port, ATMEL_US_TTGR, port->iso7816.tg);
+		/* select mck clock, and output  */
+		mode |= ATMEL_US_USCLKS_MCK | ATMEL_US_CLKO;
+		/* set max iterations */
+		mode |= ATMEL_US_MAX_ITER(3);
+		if ((port->iso7816.flags & SER_ISO7816_T_PARAM)
+				== SER_ISO7816_T(0))
+			mode |= ATMEL_US_USMODE_ISO7816_T0;
+		else
+			mode |= ATMEL_US_USMODE_ISO7816_T1;
 	} else if (termios->c_cflag & CRTSCTS) {
 		/* RS232 with hardware handshake (RTS/CTS) */
 		if (atmel_use_fifo(port) &&
@@ -2175,7 +2347,8 @@  static void atmel_set_termios(struct uart_port *port, struct ktermios *termios,
 	}
 	quot = cd | fp << ATMEL_US_FP_OFFSET;
 
-	atmel_uart_writel(port, ATMEL_US_BRGR, quot);
+	if (!(port->iso7816.flags & SER_ISO7816_ENABLED))
+		atmel_uart_writel(port, ATMEL_US_BRGR, quot);
 	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RSTSTA | ATMEL_US_RSTRX);
 	atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_TXEN | ATMEL_US_RXEN);
 	atmel_port->tx_stopped = false;
@@ -2355,6 +2528,7 @@  static int atmel_init_port(struct atmel_uart_port *atmel_port,
 	port->mapbase	= pdev->resource[0].start;
 	port->irq	= pdev->resource[1].start;
 	port->rs485_config	= atmel_config_rs485;
+	port->iso7816_config	= atmel_config_iso7816;
 	port->membase	= NULL;
 
 	memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
@@ -2378,8 +2552,12 @@  static int atmel_init_port(struct atmel_uart_port *atmel_port,
 		/* only enable clock when USART is in use */
 	}
 
-	/* Use TXEMPTY for interrupt when rs485 else TXRDY or ENDTX|TXBUFE */
-	if (port->rs485.flags & SER_RS485_ENABLED)
+	/*
+	 * Use TXEMPTY for interrupt when rs485 or ISO7816 else TXRDY or
+	 * ENDTX|TXBUFE
+	 */
+	if (port->rs485.flags & SER_RS485_ENABLED ||
+	    port->iso7816.flags & SER_ISO7816_ENABLED)
 		atmel_port->tx_done_mask = ATMEL_US_TXEMPTY;
 	else if (atmel_use_pdc_tx(port)) {
 		port->fifosize = PDC_BUFFER_SIZE;
@@ -2719,6 +2897,11 @@  static int atmel_serial_probe(struct platform_device *pdev)
 	}
 
 	atmel_port = &atmel_ports[ret];
+	atmel_port->pdata = of_device_get_match_data(&pdev->dev);
+	if (!atmel_port->pdata) {
+		ret = -EINVAL;
+		goto err;
+	}
 	atmel_port->backup_imr = 0;
 	atmel_port->uart.line = ret;
 	atmel_serial_probe_fifos(atmel_port, pdev);
diff --git a/drivers/tty/serial/atmel_serial.h b/drivers/tty/serial/atmel_serial.h
index ba3a2437cde4..6911177964ad 100644
--- a/drivers/tty/serial/atmel_serial.h
+++ b/drivers/tty/serial/atmel_serial.h
@@ -78,7 +78,8 @@ 
 #define	ATMEL_US_OVER		BIT(19)	/* Oversampling Mode */
 #define	ATMEL_US_INACK		BIT(20)	/* Inhibit Non Acknowledge */
 #define	ATMEL_US_DSNACK		BIT(21)	/* Disable Successive NACK */
-#define	ATMEL_US_MAX_ITER	GENMASK(26, 24)	/* Max Iterations */
+#define	ATMEL_US_MAX_ITER_MASK	GENMASK(26, 24)	/* Max Iterations */
+#define	ATMEL_US_MAX_ITER(n)	(((n) << 24) & ATMEL_US_MAX_ITER_MASK)
 #define	ATMEL_US_FILTER		BIT(28)	/* Infrared Receive Line Filter */
 
 #define ATMEL_US_IER		0x08	/* Interrupt Enable Register */
@@ -124,7 +125,8 @@ 
 #define ATMEL_US_TTGR		0x28	/* Transmitter Timeguard Register */
 #define	ATMEL_US_TG		GENMASK(7, 0)	/* Timeguard Value */
 
-#define ATMEL_US_FIDI		0x40	/* FI DI Ratio Register */
+#define ATMEL_US_FIDIR		0x40	/* FI DI Ratio Register */
+#define ATMEL_US_FIDI		GENMASK(15, 0)	/* FIDI ratio */
 #define ATMEL_US_NER		0x44	/* Number of Errors Register */
 #define ATMEL_US_IF		0x4c	/* IrDA Filter Register */