From f303b364b41d3fc5bf879799128958400b7859aa Mon Sep 17 00:00:00 2001 From: Ulrich Hecht Date: Fri, 31 May 2013 17:57:01 +0200 Subject: serial: sh-sci: HSCIF support Adds support for "High Speed Serial Communications Interface with FIFO", essentially a SCIF with 128-byte FIFOs and more accurate baud rate generator. Signed-off-by: Ulrich Hecht Acked-by: Paul Mundt Acked-by: Greg Kroah-Hartman Signed-off-by: Simon Horman --- drivers/tty/serial/sh-sci.c | 102 ++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 94 insertions(+), 8 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 156418619949..931d6c3a792c 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; @@ -1821,6 +1889,7 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, struct plat_sci_reg *reg; unsigned int baud, smr_val, max_baud, cks; int t = -1; + unsigned int srr; /* * 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"); -- cgit v1.2.3-59-g8ed1b