serial: sh-sci: Generalize overrun handling.

This consolidates all of the broken out overrun handling and ensures that
we have sensible defaults per-port type, in addition to making sure that
overruns are flagged appropriately in the error mask for parts that
haven't explicitly disabled support for it.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

3 files changed, 77 insertions, 56 deletions

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 280c02af0eae..bb27885ea2e5 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -563,13 +563,19 @@ static int sci_handle_errors(struct uart_port *port)
         int copied = 0;
         unsigned short status = sci_in(port, SCxSR);
         struct tty_struct *tty = port->state->port.tty;
+        struct sci_port *s = to_sci_port(port);
 
-        if (status & SCxSR_ORER(port)) {
-                /* overrun error */
-                if (tty_insert_flip_char(tty, 0, TTY_OVERRUN))
-                        copied++;
+        /*
+         * Handle overruns, if supported.
+         */
+        if (s->cfg->overrun_bit != SCIx_NOT_SUPPORTED) {
+                if (status & (1 << s->cfg->overrun_bit)) {
+                        /* overrun error */
+                        if (tty_insert_flip_char(tty, 0, TTY_OVERRUN))
+                                copied++;
 
-                dev_notice(port->dev, "overrun error");
+                        dev_notice(port->dev, "overrun error");
+                }
         }
 
         if (status & SCxSR_FER(port)) {
@@ -617,12 +623,19 @@ static int sci_handle_errors(struct uart_port *port)
 static int sci_handle_fifo_overrun(struct uart_port *port)
 {
         struct tty_struct *tty = port->state->port.tty;
+        struct sci_port *s = to_sci_port(port);
         int copied = 0;
 
+        /*
+         * XXX: Technically not limited to non-SCIFs, it's simply the
+         * SCLSR check that is for the moment SCIF-specific. This
+         * probably wants to be revisited for SCIFA/B as well as for
+         * factoring in SCI overrun detection.
+         */
         if (port->type != PORT_SCIF)
                 return 0;
 
-        if ((sci_in(port, SCLSR) & SCIF_ORER) != 0) {
+        if ((sci_in(port, SCLSR) & (1 << s->cfg->overrun_bit))) {
                 sci_out(port, SCLSR, 0);
 
                 tty_insert_flip_char(tty, 0, TTY_OVERRUN);
@@ -1755,6 +1768,32 @@ static int __devinit sci_init_single(struct platform_device *dev,
         sci_port->break_timer.function = sci_break_timer;
         init_timer(&sci_port->break_timer);
 
+        /*
+         * Establish some sensible defaults for the error detection.
+         */
+        if (!p->error_mask)
+                p->error_mask = (p->type == PORT_SCI) ?
+                        SCI_DEFAULT_ERROR_MASK : SCIF_DEFAULT_ERROR_MASK;
+
+        /*
+         * Establish sensible defaults for the overrun detection, unless
+         * the part has explicitly disabled support for it.
+         */
+        if (p->overrun_bit != SCIx_NOT_SUPPORTED) {
+                if (p->type == PORT_SCI)
+                        p->overrun_bit = 5;
+                else if (p->scbrr_algo_id == SCBRR_ALGO_4)
+                        p->overrun_bit = 9;
+                else
+                        p->overrun_bit = 0;
+
+                /*
+                 * Make the error mask inclusive of overrun detection, if
+                 * supported.
+                 */
+                p->error_mask |= (1 << p->overrun_bit);
+        }
+
         sci_port->cfg           = p;
 
         port->mapbase           = p->mapbase;
diff --git a/drivers/tty/serial/sh-sci.h b/drivers/tty/serial/sh-sci.h
index ed1c09c0454a..caab353a98b5 100644
--- a/drivers/tty/serial/sh-sci.h
+++ b/drivers/tty/serial/sh-sci.h
@@ -19,11 +19,9 @@
       defined(CONFIG_ARCH_SH7372)
 # define PORT_PTCR         0xA405011EUL
 # define PORT_PVCR         0xA4050122UL
-# define SCIF_ORER         0x0200   /* overrun error bit */
 #elif defined(CONFIG_SH_RTS7751R2D)
 # define SCSPTR1 0xFFE0001C /* 8 bit SCIF */
 # define SCSPTR2 0xFFE80020 /* 16 bit SCIF */
-# define SCIF_ORER 0x0001   /* overrun error bit */
 #elif defined(CONFIG_CPU_SUBTYPE_SH7750)  || \
       defined(CONFIG_CPU_SUBTYPE_SH7750R) || \
       defined(CONFIG_CPU_SUBTYPE_SH7750S) || \
@@ -32,15 +30,12 @@
       defined(CONFIG_CPU_SUBTYPE_SH7751R)
 # define SCSPTR1 0xffe0001c /* 8  bit SCI */
 # define SCSPTR2 0xFFE80020 /* 16 bit SCIF */
-# define SCIF_ORER 0x0001   /* overrun error bit */
 #elif defined(CONFIG_CPU_SUBTYPE_SH7760)
 # define SCSPTR0 0xfe600024 /* 16 bit SCIF */
 # define SCSPTR1 0xfe610024 /* 16 bit SCIF */
 # define SCSPTR2 0xfe620024 /* 16 bit SCIF */
-# define SCIF_ORER 0x0001  /* overrun error bit */
 #elif defined(CONFIG_CPU_SUBTYPE_SH7710) || defined(CONFIG_CPU_SUBTYPE_SH7712)
 # define SCSPTR0 0xA4400000       /* 16 bit SCIF */
-# define SCIF_ORER 0x0001   /* overrun error bit */
 # define PACR 0xa4050100
 # define PBCR 0xa4050102
 #elif defined(CONFIG_CPU_SUBTYPE_SH7343)
@@ -48,35 +43,24 @@
 #elif defined(CONFIG_CPU_SUBTYPE_SH7722)
 # define PWDR                   0xA4050166
 # define PSCR                   0xA405011E
-# define SCIF_ORER              0x0001  /* overrun error bit */
 #elif defined(CONFIG_CPU_SUBTYPE_SH7366)
 # define SCPDR0                 0xA405013E      /* 16 bit SCIF0 PSDR */
 # define SCSPTR0                SCPDR0
-# define SCIF_ORER              0x0001  /* overrun error bit */
 #elif defined(CONFIG_CPU_SUBTYPE_SH7723)
 # define SCSPTR0                0xa4050160
-# define SCIF_ORER              0x0001  /* overrun error bit */
-#elif defined(CONFIG_CPU_SUBTYPE_SH7724)
-# define SCIF_ORER              0x0001  /* overrun error bit */
 #elif defined(CONFIG_CPU_SUBTYPE_SH4_202)
 # define SCSPTR2 0xffe80020 /* 16 bit SCIF */
-# define SCIF_ORER 0x0001   /* overrun error bit */
 #elif defined(CONFIG_CPU_SUBTYPE_SH7757)
 # define SCSPTR0 0xfe4b0020
-# define SCIF_ORER 0x0001
 #elif defined(CONFIG_CPU_SUBTYPE_SH7763)
 # define SCSPTR0 0xffe00024 /* 16 bit SCIF */
-# define SCIF_ORER 0x0001  /* overrun error bit */
 #elif defined(CONFIG_CPU_SUBTYPE_SH7770)
 # define SCSPTR0 0xff923020 /* 16 bit SCIF */
-# define SCIF_ORER 0x0001  /* overrun error bit */
 #elif defined(CONFIG_CPU_SUBTYPE_SH7780)
 # define SCSPTR0        0xffe00024      /* 16 bit SCIF */
-# define SCIF_ORER      0x0001          /* Overrun error bit */
 #elif defined(CONFIG_CPU_SUBTYPE_SH7785) || \
       defined(CONFIG_CPU_SUBTYPE_SH7786)
 # define SCSPTR0        0xffea0024      /* 16 bit SCIF */
-# define SCIF_ORER      0x0001          /* Overrun error bit */
 #elif defined(CONFIG_CPU_SUBTYPE_SH7201) || \
       defined(CONFIG_CPU_SUBTYPE_SH7203) || \
       defined(CONFIG_CPU_SUBTYPE_SH7206) || \
@@ -84,36 +68,12 @@
 # define SCSPTR0 0xfffe8020 /* 16 bit SCIF */
 #elif defined(CONFIG_CPU_SUBTYPE_SH7619)
 # define SCSPTR0 0xf8400020 /* 16 bit SCIF */
-# define SCIF_ORER 0x0001  /* overrun error bit */
 #elif defined(CONFIG_CPU_SUBTYPE_SHX3)
 # define SCSPTR0 0xffc30020             /* 16 bit SCIF */
-# define SCIF_ORER 0x0001               /* Overrun error bit */
 #else
 # error CPU subtype not defined
 #endif
 
-/* SCxSR SCI */
-#define SCI_TDRE  0x80 /* 7707 SCI, 7708 SCI, 7709 SCI, 7750 SCI */
-#define SCI_RDRF  0x40 /* 7707 SCI, 7708 SCI, 7709 SCI, 7750 SCI */
-#define SCI_ORER  0x20 /* 7707 SCI, 7708 SCI, 7709 SCI, 7750 SCI */
-#define SCI_FER   0x10 /* 7707 SCI, 7708 SCI, 7709 SCI, 7750 SCI */
-#define SCI_PER   0x08 /* 7707 SCI, 7708 SCI, 7709 SCI, 7750 SCI */
-#define SCI_TEND  0x04 /* 7707 SCI, 7708 SCI, 7709 SCI, 7750 SCI */
-/*      SCI_MPB   0x02  * 7707 SCI, 7708 SCI, 7709 SCI, 7750 SCI */
-/*      SCI_MPBT  0x01  * 7707 SCI, 7708 SCI, 7709 SCI, 7750 SCI */
-
-#define SCI_ERRORS ( SCI_PER | SCI_FER | SCI_ORER)
-
-/* SCxSR SCIF */
-#define SCIF_ER    0x0080 /* 7705 SCIF, 7707 SCIF, 7709 SCIF, 7750 SCIF */
-#define SCIF_TEND  0x0040 /* 7705 SCIF, 7707 SCIF, 7709 SCIF, 7750 SCIF */
-#define SCIF_TDFE  0x0020 /* 7705 SCIF, 7707 SCIF, 7709 SCIF, 7750 SCIF */
-#define SCIF_BRK   0x0010 /* 7705 SCIF, 7707 SCIF, 7709 SCIF, 7750 SCIF */
-#define SCIF_FER   0x0008 /* 7705 SCIF, 7707 SCIF, 7709 SCIF, 7750 SCIF */
-#define SCIF_PER   0x0004 /* 7705 SCIF, 7707 SCIF, 7709 SCIF, 7750 SCIF */
-#define SCIF_RDF   0x0002 /* 7705 SCIF, 7707 SCIF, 7709 SCIF, 7750 SCIF */
-#define SCIF_DR    0x0001 /* 7705 SCIF, 7707 SCIF, 7709 SCIF, 7750 SCIF */
-
 #if defined(CONFIG_CPU_SUBTYPE_SH7705) || \
     defined(CONFIG_CPU_SUBTYPE_SH7720) || \
     defined(CONFIG_CPU_SUBTYPE_SH7721) || \
@@ -121,35 +81,27 @@
     defined(CONFIG_ARCH_SH7367) || \
     defined(CONFIG_ARCH_SH7377) || \
     defined(CONFIG_ARCH_SH7372)
-# define SCIF_ORER    0x0200
-# define SCIF_ERRORS ( SCIF_PER | SCIF_FER | SCIF_ER | SCIF_BRK | SCIF_ORER)
 # define SCIF_RFDC_MASK 0x007f
 # define SCIF_TXROOM_MAX 64
 #elif defined(CONFIG_CPU_SUBTYPE_SH7763)
-# define SCIF_ERRORS ( SCIF_PER | SCIF_FER | SCIF_ER | SCIF_BRK )
 # define SCIF_RFDC_MASK 0x007f
 # define SCIF_TXROOM_MAX 64
 /* SH7763 SCIF2 support */
 # define SCIF2_RFDC_MASK 0x001f
 # define SCIF2_TXROOM_MAX 16
 #else
-# define SCIF_ERRORS ( SCIF_PER | SCIF_FER | SCIF_ER | SCIF_BRK)
 # define SCIF_RFDC_MASK 0x001f
 # define SCIF_TXROOM_MAX 16
 #endif
 
-#ifndef SCIF_ORER
-#define SCIF_ORER       0x0000
-#endif
-
 #define SCxSR_TEND(port)        (((port)->type == PORT_SCI) ? SCI_TEND   : SCIF_TEND)
-#define SCxSR_ERRORS(port)      (((port)->type == PORT_SCI) ? SCI_ERRORS : SCIF_ERRORS)
 #define SCxSR_RDxF(port)        (((port)->type == PORT_SCI) ? SCI_RDRF   : SCIF_RDF)
 #define SCxSR_TDxE(port)        (((port)->type == PORT_SCI) ? SCI_TDRE   : SCIF_TDFE)
 #define SCxSR_FER(port)         (((port)->type == PORT_SCI) ? SCI_FER    : SCIF_FER)
 #define SCxSR_PER(port)         (((port)->type == PORT_SCI) ? SCI_PER    : SCIF_PER)
 #define SCxSR_BRK(port)         (((port)->type == PORT_SCI) ? 0x00       : SCIF_BRK)
-#define SCxSR_ORER(port)        (((port)->type == PORT_SCI) ? SCI_ORER   : SCIF_ORER)
+
+#define SCxSR_ERRORS(port)      (to_sci_port(port)->cfg->error_mask)
 
 #if defined(CONFIG_CPU_SUBTYPE_SH7705) || \
     defined(CONFIG_CPU_SUBTYPE_SH7720) || \
diff --git a/include/linux/serial_sci.h b/include/linux/serial_sci.h
index a2afc9fbe186..5fac3bccfd87 100644
--- a/include/linux/serial_sci.h
+++ b/include/linux/serial_sci.h
@@ -8,6 +8,8 @@
  * Generic header for SuperH SCI(F) (used by sh/sh64/h8300 and related parts)
  */
 
+#define SCIx_NOT_SUPPORTED      (-1)
+
 enum {
         SCBRR_ALGO_1,           /* ((clk + 16 * bps) / (16 * bps) - 1) */
         SCBRR_ALGO_2,           /* ((clk + 16 * bps) / (32 * bps) - 1) */
@@ -25,6 +27,28 @@ enum {
 #define SCSCR_CKE1      (1 << 1)
 #define SCSCR_CKE0      (1 << 0)
 
+/* SCxSR SCI */
+#define SCI_TDRE  0x80
+#define SCI_RDRF  0x40
+#define SCI_ORER  0x20
+#define SCI_FER   0x10
+#define SCI_PER   0x08
+#define SCI_TEND  0x04
+
+#define SCI_DEFAULT_ERROR_MASK (SCI_PER | SCI_FER)
+
+/* SCxSR SCIF */
+#define SCIF_ER    0x0080
+#define SCIF_TEND  0x0040
+#define SCIF_TDFE  0x0020
+#define SCIF_BRK   0x0010
+#define SCIF_FER   0x0008
+#define SCIF_PER   0x0004
+#define SCIF_RDF   0x0002
+#define SCIF_DR    0x0001
+
+#define SCIF_DEFAULT_ERROR_MASK (SCIF_PER | SCIF_FER | SCIF_ER | SCIF_BRK)
+
 /* Offsets into the sci_port->irqs array */
 enum {
         SCIx_ERI_IRQ,
@@ -56,6 +80,12 @@ struct plat_sci_port {
         unsigned int    scbrr_algo_id;          /* SCBRR calculation algo */
         unsigned int    scscr;                  /* SCSCR initialization */
 
+        /*
+         * Platform overrides if necessary, defaults otherwise.
+         */
+        int             overrun_bit;
+        unsigned int    error_mask;
+
         struct device   *dma_dev;
 
         unsigned int    dma_slave_tx;