[PATCH 2/3] tty/serial: atmel: add ISO7816 support
From: gregkh@linuxfoundation.org (Greg KH)
Date: 2018-07-12 15:01:59
Also in:
linux-arch, linux-serial, lkml
On Wed, Jul 11, 2018 at 03:16:37PM +0200, Ludovic Desroches wrote:
quoted hunk ↗ jump to hunk
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. Report NACK and ITER errors in irq handler. Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> [ludovic.desroches at 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 | 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...
quoted hunk ↗ jump to hunk
@@ -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