On Wed, Jul 11, 2018 at 03:16:37PM +0200, Ludovic Desroches wrote:
> From: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
>
> 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.
> Report NACK and ITER errors in irq handler.
>
> Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
> [ludovic.desroches@xxxxxxxxxxxxx: rebase, add check on fidi ratio, checkpatch fixes]
> Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx>
> ---
> drivers/tty/serial/atmel_serial.c | 175 +++++++++++++++++++++++++++++++++++---
> drivers/tty/serial/atmel_serial.h | 3 +-
> 2 files changed, 167 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
> index 8e4428725848..0118b219f3a8 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>
>
> @@ -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;
> @@ -362,6 +365,136 @@ 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);
> + dev_dbg(port->dev, "ISO7816 mck_rate = %lld\n", mck_rate);
> + do_div(mck_rate, iso7816conf->clk);
> + cd = mck_rate;
> + dev_dbg(port->dev, "ISO7816 clk = %d. CD = %d\n", iso7816conf->clk, cd);
> + return cd;
> +}
> +
> +static unsigned int atmel_calc_fidi(struct uart_port *port,
> + struct serial_iso7816 *iso7816conf)
> +{
> + u64 fidi = 0;
> +
> + dev_dbg(port->dev, "ISO7816 fi(%d) / di(%d)\n",
> + iso7816conf->sc_fi, iso7816conf->sc_di);
Do you still need all of the debugging code? Shouldn't ftrace give you
all of this?
> + if (iso7816conf->sc_fi && iso7816conf->sc_di) {
> + fidi = (u64)iso7816conf->sc_fi;
> + do_div(fidi, iso7816conf->sc_di);
> + }
> + dev_dbg(port->dev, "ISO7816 fidi = 0x%x\n", (u32)fidi);
> + 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, t;
> + unsigned int cd, fidi;
> + int ret = 0;
> +
> + /* Disable RX and TX */
> + atmel_uart_writel(port, ATMEL_US_CR, ATMEL_US_RXDIS | ATMEL_US_TXDIS);
> + /* Disable interrupts */
> + atmel_uart_writel(port, ATMEL_US_IDR, atmel_port->tx_done_mask);
> +
> + mode = atmel_uart_readl(port, ATMEL_US_MR);
> +
> + if (!(port->iso7816.flags & SER_ISO7816_ENABLED)) {
> + /* port not yet in iso7816 mode: store configuration */
> + atmel_port->backup_mode = mode;
> + atmel_port->backup_brgr = atmel_uart_readl(port, ATMEL_US_BRGR);
> + }
Are you really validating all of the fields in this structure for valid
values correctly? It feels like you are missing some here...
> @@ -1281,6 +1417,9 @@ 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_err(port->dev, "ISO7816 ERROR (0x%08x)\n", pending);
What can someone do with this?
If nothing, then why check or tell the user about it? They will ignore
it :(
thanks,
greg k-h
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