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 From d4759ded3bdf3eb004d583011707fdc21aeda94e Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Thu, 20 Jun 2013 21:09:45 +0900 Subject: serial: sh-sci: Initialise variables before access in sci_set_termios() This change addresses two warnings that are flagged by gcc relating to potential access to the ssr and cks variables while they are uninitialised. I have addressed this by initialising the values to the defaults present in sci_baud_calc_hscif(). It is my analysis that cks is always initialised if used but that without this change ssr may be accessed while uninitialised. The code altered by this patch was introduced by commit f303b364b41d3fc5bf879799128958400b7859aa ("serial: sh-sci: HSCIF support"). Reported-by: Arnd Bergmann Acked-by: Greg Kroah-Hartman Signed-off-by: Simon Horman --- drivers/tty/serial/sh-sci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 931d6c3a792c..7477e0ea5cdb 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1887,9 +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; + unsigned int srr = 15; /* * earlyprintk comes here early on with port->uartclk set to zero. -- cgit v1.2.3