From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shinya Kuribayashi Date: Wed, 07 Nov 2012 06:59:45 +0000 Subject: [PATCH 06/10] serial: sh-sci: support lower baud rate Message-Id: <509A06E1.6090908@renesas.com> List-Id: References: <509A0658.1010503@renesas.com> In-Reply-To: <509A0658.1010503@renesas.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org Support prescaler 1/16 and 1/64, in addition to current 1 and 1/4. Supporting below 2400bps was dropped long time ago in mainline. Since then, setting lower rate has been resulting in erroneous register value, without indicating any errors through API. This patch adds more prescaler to support lower rates again. This still doesn't check range, but we won't hit the case because even 50bps at 48MHz clock is now supported. Signed-off-by: Takashi Yoshii Signed-off-by: Shinya Kuribayashi --- drivers/tty/serial/sh-sci.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index ffeca65..3021912 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1814,7 +1814,7 @@ 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; + unsigned int baud, smr_val, max_baud, cks; int t = -1; /* @@ -1848,21 +1848,18 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, uart_update_timeout(port, termios->c_cflag, baud); - serial_port_out(port, SCSMR, smr_val); + for (cks = 0; t >= 256 && cks <= 3; cks++) + t >>= 2; - dev_dbg(port->dev, "%s: SMR %x, t %x, SCSCR %x\n", __func__, smr_val, t, - s->cfg->scscr); + 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) { - if (t >= 256) { - serial_port_out(port, SCSMR, (serial_port_in(port, SCSMR) & ~3) | 1); - t >>= 2; - } else - serial_port_out(port, SCSMR, serial_port_in(port, SCSMR) & ~3); - + serial_port_out(port, SCSMR, (smr_val & ~3) | cks); serial_port_out(port, SCBRR, t); udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */ - } + } else + serial_port_out(port, SCSMR, smr_val); sci_init_pins(port, termios->c_cflag); -- 1.7.12.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shinya Kuribayashi Subject: [PATCH 06/10] serial: sh-sci: support lower baud rate Date: Wed, 07 Nov 2012 15:59:45 +0900 Message-ID: <509A06E1.6090908@renesas.com> References: <509A0658.1010503@renesas.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <509A0658.1010503@renesas.com> Sender: linux-sh-owner@vger.kernel.org To: lethal@linux-sh.org, magnus.damm@gmail.com, takashi.yoshii.zj@renesas.com, alan@linux.intel.com, gregkh@linuxfoundation.org Cc: rjw@sisk.pl, linux-serial@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sh@vger.kernel.org List-Id: linux-serial@vger.kernel.org Support prescaler 1/16 and 1/64, in addition to current 1 and 1/4. Supporting below 2400bps was dropped long time ago in mainline. Since then, setting lower rate has been resulting in erroneous register value, without indicating any errors through API. This patch adds more prescaler to support lower rates again. This still doesn't check range, but we won't hit the case because even 50bps at 48MHz clock is now supported. Signed-off-by: Takashi Yoshii Signed-off-by: Shinya Kuribayashi --- drivers/tty/serial/sh-sci.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index ffeca65..3021912 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1814,7 +1814,7 @@ 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; + unsigned int baud, smr_val, max_baud, cks; int t = -1; /* @@ -1848,21 +1848,18 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, uart_update_timeout(port, termios->c_cflag, baud); - serial_port_out(port, SCSMR, smr_val); + for (cks = 0; t >= 256 && cks <= 3; cks++) + t >>= 2; - dev_dbg(port->dev, "%s: SMR %x, t %x, SCSCR %x\n", __func__, smr_val, t, - s->cfg->scscr); + 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) { - if (t >= 256) { - serial_port_out(port, SCSMR, (serial_port_in(port, SCSMR) & ~3) | 1); - t >>= 2; - } else - serial_port_out(port, SCSMR, serial_port_in(port, SCSMR) & ~3); - + serial_port_out(port, SCSMR, (smr_val & ~3) | cks); serial_port_out(port, SCBRR, t); udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */ - } + } else + serial_port_out(port, SCSMR, smr_val); sci_init_pins(port, termios->c_cflag); -- 1.7.12.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: shinya.kuribayashi.px@renesas.com (Shinya Kuribayashi) Date: Wed, 07 Nov 2012 15:59:45 +0900 Subject: [PATCH 06/10] serial: sh-sci: support lower baud rate In-Reply-To: <509A0658.1010503@renesas.com> References: <509A0658.1010503@renesas.com> Message-ID: <509A06E1.6090908@renesas.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Support prescaler 1/16 and 1/64, in addition to current 1 and 1/4. Supporting below 2400bps was dropped long time ago in mainline. Since then, setting lower rate has been resulting in erroneous register value, without indicating any errors through API. This patch adds more prescaler to support lower rates again. This still doesn't check range, but we won't hit the case because even 50bps at 48MHz clock is now supported. Signed-off-by: Takashi Yoshii Signed-off-by: Shinya Kuribayashi --- drivers/tty/serial/sh-sci.c | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index ffeca65..3021912 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1814,7 +1814,7 @@ 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; + unsigned int baud, smr_val, max_baud, cks; int t = -1; /* @@ -1848,21 +1848,18 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, uart_update_timeout(port, termios->c_cflag, baud); - serial_port_out(port, SCSMR, smr_val); + for (cks = 0; t >= 256 && cks <= 3; cks++) + t >>= 2; - dev_dbg(port->dev, "%s: SMR %x, t %x, SCSCR %x\n", __func__, smr_val, t, - s->cfg->scscr); + 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) { - if (t >= 256) { - serial_port_out(port, SCSMR, (serial_port_in(port, SCSMR) & ~3) | 1); - t >>= 2; - } else - serial_port_out(port, SCSMR, serial_port_in(port, SCSMR) & ~3); - + serial_port_out(port, SCSMR, (smr_val & ~3) | cks); serial_port_out(port, SCBRR, t); udelay((1000000+(baud-1)) / baud); /* Wait one bit interval */ - } + } else + serial_port_out(port, SCSMR, smr_val); sci_init_pins(port, termios->c_cflag); -- 1.7.12.4