From 0174e5ca82ba6bd62ab870e5781b72bd5397f1c3 Mon Sep 17 00:00:00 2001 From: Teppei Kamijou Date: Fri, 16 Nov 2012 10:51:55 +0900 Subject: [PATCH] serial: sh-sci: console runtime PM support (revisit) The commit 1ba7622094 (serial: sh-sci: console Runtime PM support, from Magnus Damm , 2011-08-03), tried to support console runtime PM, but unfortunately it didn't work for us for some reason. We did not investigated further at that time, instead would like to propose a different approach. In Linux tty/serial world, to get console PM work properly, a serial client driver does not have to maintain .runtime_suspend()/..resume() calls itself, but can leave console power power management handling to the serial core driver. This patch moves the sh-sci driver in that direction. Notes: * There is room to optimize console runtime PM more aggressively by maintaining additional local runtime PM calls, but as a first step having .pm() operation would suffice. * We still have a couple of direct calls to sci_port_enable/..disable left in the driver. We have to live with them, because they're out of serial core's help. Signed-off-by: Teppei Kamijou Signed-off-by: Shinya Kuribayashi Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/sh-sci.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 602d0781c6c8..8aade611d1a8 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1747,8 +1747,6 @@ static int sci_startup(struct uart_port *port) dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); - sci_port_enable(s); - ret = sci_request_irq(s); if (unlikely(ret < 0)) return ret; @@ -1772,8 +1770,6 @@ static void sci_shutdown(struct uart_port *port) sci_free_dma(port); sci_free_irq(s); - - sci_port_disable(s); } static unsigned int sci_scbrr_calc(unsigned int algo_id, unsigned int bps, @@ -1922,6 +1918,21 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, sci_port_disable(s); } +static void sci_pm(struct uart_port *port, unsigned int state, + unsigned int oldstate) +{ + struct sci_port *sci_port = to_sci_port(port); + + switch (state) { + case 3: + sci_port_disable(sci_port); + break; + default: + sci_port_enable(sci_port); + break; + } +} + static const char *sci_type(struct uart_port *port) { switch (port->type) { @@ -2043,6 +2054,7 @@ static struct uart_ops sci_uart_ops = { .startup = sci_startup, .shutdown = sci_shutdown, .set_termios = sci_set_termios, + .pm = sci_pm, .type = sci_type, .release_port = sci_release_port, .request_port = sci_request_port, @@ -2196,16 +2208,12 @@ static void serial_console_write(struct console *co, const char *s, struct uart_port *port = &sci_port->port; unsigned short bits; - sci_port_enable(sci_port); - uart_console_write(port, s, count, serial_console_putchar); /* wait until fifo is empty and last bit has been transmitted */ bits = SCxSR_TDxE(port) | SCxSR_TEND(port); while ((serial_port_in(port, SCxSR) & bits) != bits) cpu_relax(); - - sci_port_disable(sci_port); } static int __devinit serial_console_setup(struct console *co, char *options) @@ -2237,12 +2245,9 @@ static int __devinit serial_console_setup(struct console *co, char *options) if (unlikely(ret != 0)) return ret; - sci_port_enable(sci_port); - if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); - /* TODO: disable clock */ return uart_set_options(port, co, baud, parity, bits, flow); } -- 2.20.1