From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Vallee Subject: [PATCH] sc16is7xx: make sure device is in suspend once probed Date: Tue, 19 Jul 2016 16:29:36 +0200 Message-ID: <1468938576-19508-1-git-send-email-fvallee@eukrea.fr> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Jiri Slaby , Greg Kroah-Hartman , linux-serial@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Florian Vallee List-Id: linux-serial@vger.kernel.org Previously sc16is7xx_power was called in order to set the device to a low power mode. However since SC16IS7XX_EFR_ENABLE_BIT was not set beforehand this suspend request had not effect. Also, soft-reset the device prior to port initialization. It may otherwise be in a state (interrupt pending, fifo not empty) which prevents it from sleeping. Signed-off-by: Florian Vallee --- drivers/tty/serial/sc16is7xx.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index f36e6df..a9d94f7 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -1205,6 +1205,10 @@ static int sc16is7xx_probe(struct device *dev, } #endif + /* reset device, purging any pending irq / data */ + regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT, + SC16IS7XX_IOCONTROL_SRESET_BIT); + for (i = 0; i < devtype->nr_uart; ++i) { s->p[i].line = i; /* Initialize port data */ @@ -1234,6 +1238,22 @@ static int sc16is7xx_probe(struct device *dev, init_kthread_work(&s->p[i].reg_work, sc16is7xx_reg_proc); /* Register port */ uart_add_one_port(&sc16is7xx_uart, &s->p[i].port); + + /* Enable EFR */ + sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG, + SC16IS7XX_LCR_CONF_MODE_B); + + regcache_cache_bypass(s->regmap, true); + + /* Enable write access to enhanced features */ + sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFR_REG, + SC16IS7XX_EFR_ENABLE_BIT); + + regcache_cache_bypass(s->regmap, false); + + /* Restore access to general registers */ + sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_LCR_REG, 0x00); + /* Go to suspend mode */ sc16is7xx_power(&s->p[i].port, 0); } -- 2.7.4