Merge tag 'renesas-sh-sci-for-v3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into next/late

Renesas sh-sci updates for v3.11

HSCIF support by Ulrich Hecht.

* tag 'renesas-sh-sci-for-v3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  serial: sh-sci: Initialise variables before access in sci_set_termios()
  ARM: shmobile: r8a7790: don't use external clock for SCIFs
  ARM: shmobile: r8a7790: HSCIF support
  serial: sh-sci: HSCIF support

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 95 insertions, 9 deletions

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 156418619949..7477e0ea5cdb 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -146,6 +146,7 @@ static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
                 [SCRFDR]        = sci_reg_invalid,
                 [SCSPTR]        = sci_reg_invalid,
                 [SCLSR]         = sci_reg_invalid,
+                [HSSRR]         = sci_reg_invalid,
         },
 
         /*
@@ -165,6 +166,7 @@ static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
                 [SCRFDR]        = sci_reg_invalid,
                 [SCSPTR]        = sci_reg_invalid,
                 [SCLSR]         = sci_reg_invalid,
+                [HSSRR]         = sci_reg_invalid,
         },
 
         /*
@@ -183,6 +185,7 @@ static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
                 [SCRFDR]        = sci_reg_invalid,
                 [SCSPTR]        = sci_reg_invalid,
                 [SCLSR]         = sci_reg_invalid,
+                [HSSRR]         = sci_reg_invalid,
         },
 
         /*
@@ -201,6 +204,7 @@ static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
                 [SCRFDR]        = { 0x3c, 16 },
                 [SCSPTR]        = sci_reg_invalid,
                 [SCLSR]         = sci_reg_invalid,
+                [HSSRR]         = sci_reg_invalid,
         },
 
         /*
@@ -220,6 +224,7 @@ static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
                 [SCRFDR]        = sci_reg_invalid,
                 [SCSPTR]        = { 0x20, 16 },
                 [SCLSR]         = { 0x24, 16 },
+                [HSSRR]         = sci_reg_invalid,
         },
 
         /*
@@ -238,6 +243,7 @@ static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
                 [SCRFDR]        = sci_reg_invalid,
                 [SCSPTR]        = sci_reg_invalid,
                 [SCLSR]         = sci_reg_invalid,
+                [HSSRR]         = sci_reg_invalid,
         },
 
         /*
@@ -256,6 +262,26 @@ static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
                 [SCRFDR]        = sci_reg_invalid,
                 [SCSPTR]        = { 0x20, 16 },
                 [SCLSR]         = { 0x24, 16 },
+                [HSSRR]         = sci_reg_invalid,
+        },
+
+        /*
+         * Common HSCIF definitions.
+         */
+        [SCIx_HSCIF_REGTYPE] = {
+                [SCSMR]         = { 0x00, 16 },
+                [SCBRR]         = { 0x04,  8 },
+                [SCSCR]         = { 0x08, 16 },
+                [SCxTDR]        = { 0x0c,  8 },
+                [SCxSR]         = { 0x10, 16 },
+                [SCxRDR]        = { 0x14,  8 },
+                [SCFCR]         = { 0x18, 16 },
+                [SCFDR]         = { 0x1c, 16 },
+                [SCTFDR]        = sci_reg_invalid,
+                [SCRFDR]        = sci_reg_invalid,
+                [SCSPTR]        = { 0x20, 16 },
+                [SCLSR]         = { 0x24, 16 },
+                [HSSRR]         = { 0x40, 16 },
         },
 
         /*
@@ -275,6 +301,7 @@ static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
                 [SCRFDR]        = sci_reg_invalid,
                 [SCSPTR]        = sci_reg_invalid,
                 [SCLSR]         = { 0x24, 16 },
+                [HSSRR]         = sci_reg_invalid,
         },
 
         /*
@@ -294,6 +321,7 @@ static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
                 [SCRFDR]        = { 0x20, 16 },
                 [SCSPTR]        = { 0x24, 16 },
                 [SCLSR]         = { 0x28, 16 },
+                [HSSRR]         = sci_reg_invalid,
         },
 
         /*
@@ -313,6 +341,7 @@ static struct plat_sci_reg sci_regmap[SCIx_NR_REGTYPES][SCIx_NR_REGS] = {
                 [SCRFDR]        = sci_reg_invalid,
                 [SCSPTR]        = sci_reg_invalid,
                 [SCLSR]         = sci_reg_invalid,
+                [HSSRR]         = sci_reg_invalid,
         },
 };
 
@@ -374,6 +403,9 @@ static int sci_probe_regmap(struct plat_sci_port *cfg)
                  */
                 cfg->regtype = SCIx_SH4_SCIF_REGTYPE;
                 break;
+        case PORT_HSCIF:
+                cfg->regtype = SCIx_HSCIF_REGTYPE;
+                break;
         default:
                 printk(KERN_ERR "Can't probe register map for given port\n");
                 return -EINVAL;
@@ -1798,6 +1830,42 @@ static unsigned int sci_scbrr_calc(unsigned int algo_id, unsigned int bps,
         return ((freq + 16 * bps) / (32 * bps) - 1);
 }
 
+/* calculate sample rate, BRR, and clock select for HSCIF */
+static void sci_baud_calc_hscif(unsigned int bps, unsigned long freq,
+                                int *brr, unsigned int *srr,
+                                unsigned int *cks)
+{
+        int sr, c, br, err;
+        int min_err = 1000; /* 100% */
+
+        /* Find the combination of sample rate and clock select with the
+           smallest deviation from the desired baud rate. */
+        for (sr = 8; sr <= 32; sr++) {
+                for (c = 0; c <= 3; c++) {
+                        /* integerized formulas from HSCIF documentation */
+                        br = freq / (sr * (1 << (2 * c + 1)) * bps) - 1;
+                        if (br < 0 || br > 255)
+                                continue;
+                        err = freq / ((br + 1) * bps * sr *
+                              (1 << (2 * c + 1)) / 1000) - 1000;
+                        if (min_err > err) {
+                                min_err = err;
+                                *brr = br;
+                                *srr = sr - 1;
+                                *cks = c;
+                        }
+                }
+        }
+
+        if (min_err == 1000) {
+                WARN_ON(1);
+                /* use defaults */
+                *brr = 255;
+                *srr = 15;
+                *cks = 0;
+        }
+}
+
 static void sci_reset(struct uart_port *port)
 {
         struct plat_sci_reg *reg;
@@ -1819,8 +1887,9 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
 {
         struct sci_port *s = to_sci_port(port);
         struct plat_sci_reg *reg;
-        unsigned int baud, smr_val, max_baud, cks;
+        unsigned int baud, smr_val, max_baud, cks = 0;
         int t = -1;
+        unsigned int srr = 15;
 
         /*
          * earlyprintk comes here early on with port->uartclk set to zero.
@@ -1833,8 +1902,17 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
         max_baud = port->uartclk ? port->uartclk / 16 : 115200;
 
         baud = uart_get_baud_rate(port, termios, old, 0, max_baud);
-        if (likely(baud && port->uartclk))
-                t = sci_scbrr_calc(s->cfg->scbrr_algo_id, baud, port->uartclk);
+        if (likely(baud && port->uartclk)) {
+                if (s->cfg->scbrr_algo_id == SCBRR_ALGO_6) {
+                        sci_baud_calc_hscif(baud, port->uartclk, &t, &srr,
+                                            &cks);
+                } else {
+                        t = sci_scbrr_calc(s->cfg->scbrr_algo_id, baud,
+                                           port->uartclk);
+                        for (cks = 0; t >= 256 && cks <= 3; cks++)
+                                t >>= 2;
+                }
+        }
 
         sci_port_enable(s);
 
@@ -1853,15 +1931,15 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
 
         uart_update_timeout(port, termios->c_cflag, baud);
 
-        for (cks = 0; t >= 256 && cks <= 3; cks++)
-                t >>= 2;
-
         dev_dbg(port->dev, "%s: SMR %x, cks %x, t %x, SCSCR %x\n",
                 __func__, smr_val, cks, t, s->cfg->scscr);
 
         if (t >= 0) {
                 serial_port_out(port, SCSMR, (smr_val & ~3) | cks);
                 serial_port_out(port, SCBRR, t);
+                reg = sci_getreg(port, HSSRR);
+                if (reg->size)
+                        serial_port_out(port, HSSRR, srr | HSCIF_SRE);
                 udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */
         } else
                 serial_port_out(port, SCSMR, smr_val);
@@ -1947,6 +2025,8 @@ static const char *sci_type(struct uart_port *port)
                 return "scifa";
         case PORT_SCIFB:
                 return "scifb";
+        case PORT_HSCIF:
+                return "hscif";
         }
 
         return NULL;
@@ -1960,7 +2040,10 @@ static inline unsigned long sci_port_size(struct uart_port *port)
          * from platform resource data at such a time that ports begin to
          * behave more erratically.
          */
-        return 64;
+        if (port->type == PORT_HSCIF)
+                return 96;
+        else
+                return 64;
 }
 
 static int sci_remap_port(struct uart_port *port)
@@ -2085,6 +2168,9 @@ static int sci_init_single(struct platform_device *dev,
         case PORT_SCIFB:
                 port->fifosize = 256;
                 break;
+        case PORT_HSCIF:
+                port->fifosize = 128;
+                break;
         case PORT_SCIFA:
                 port->fifosize = 64;
                 break;
@@ -2325,7 +2411,7 @@ static inline int sci_probe_earlyprintk(struct platform_device *pdev)
 #endif /* CONFIG_SERIAL_SH_SCI_CONSOLE */
 
 static char banner[] __initdata =
-        KERN_INFO "SuperH SCI(F) driver initialized\n";
+        KERN_INFO "SuperH (H)SCI(F) driver initialized\n";
 
 static struct uart_driver sci_uart_driver = {
         .owner          = THIS_MODULE,
@@ -2484,4 +2570,4 @@ module_exit(sci_exit);
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:sh-sci");
 MODULE_AUTHOR("Paul Mundt");
-MODULE_DESCRIPTION("SuperH SCI(F) serial driver");
+MODULE_DESCRIPTION("SuperH (H)SCI(F) serial driver");