Commit 377fedd1 authored by Nicolas Ferre's avatar Nicolas Ferre Committed by Greg Kroah-Hartman
Browse files

tty/serial: atmel: add ISO7816 support 



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: default avatarNicolas Ferre <nicolas.ferre@microchip.com>
[ludovic.desroches@microchip.com: rebase, add check on fidi ratio, checkpatch fixes]
Signed-off-by: default avatarLudovic Desroches <ludovic.desroches@microchip.com>
Acked-by: default avatarRichard Genoud <richard.genoud@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ad8c0eaa

drivers/tty/serial/atmel_serial.c

+179 −11
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#include <linux/suspend.h>

#include <linux/mm.h>



#include <asm/div64.h>

#include <asm/io.h>

#include <asm/ioctls.h>
@@ -147,6 +148,8 @@ 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;
@@ -163,6 +166,10 @@ struct atmel_uart_port { 
	unsigned int		pending_status;

	spinlock_t		lock_suspended;



	/* ISO7816 */

	unsigned int		fidi_min;

	unsigned int		fidi_max;



#ifdef CONFIG_PM

	struct {

		u32		cr;
@@ -361,6 +368,127 @@ 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->fidi_min

			   || fidi > atmel_port->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_FIDI, 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_FIDI, 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.

 */
@@ -480,8 +608,9 @@ 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);

}
@@ -499,8 +628,9 @@ 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))
@@ -798,8 +928,9 @@ 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);

	}
@@ -1282,6 +1413,9 @@ 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);

}



/*
@@ -1374,8 +1508,9 @@ 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);

		}
@@ -1727,6 +1862,22 @@ static void atmel_get_ip_name(struct uart_port *port) 
		atmel_port->has_frac_baudrate = true;

		atmel_port->has_hw_timer = true;

		atmel_port->rtor = ATMEL_US_RTOR;

		version = atmel_uart_readl(port, ATMEL_US_VERSION);

		switch (version) {

		case 0x814:	/* sama5d2 */

			/* fall through */

		case 0x701:	/* sama5d4 */

			atmel_port->fidi_min = 3;

			atmel_port->fidi_max = 65535;

			break;

		case 0x502:	/* sam9x5, sama5d3 */

			atmel_port->fidi_min = 3;

			atmel_port->fidi_max = 2047;

			break;

		default:

			atmel_port->fidi_min = 1;

			atmel_port->fidi_max = 2047;

		}

	} else if (name == dbgu_uart) {

		dev_dbg(port->dev, "Dbgu or uart without hw timer\n");

	} else {
@@ -2100,6 +2251,17 @@ 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) &&
@@ -2176,6 +2338,7 @@ static void atmel_set_termios(struct uart_port *port, struct ktermios *termios, 
	}

	quot = cd | fp << ATMEL_US_FP_OFFSET;



	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);
@@ -2357,6 +2520,7 @@ static int atmel_init_port(struct atmel_uart_port *atmel_port, 
	port->mapbase		= mpdev->resource[0].start;

	port->irq		= mpdev->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));
@@ -2380,8 +2544,12 @@ 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;

drivers/tty/serial/atmel_serial.h

+2 −1
Original line number Diff line number Diff line
@@ -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 */

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