From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: MIME-Version: 1.0 In-Reply-To: <1524207555-165403-2-git-send-email-shawn.lin@rock-chips.com> References: <1524207555-165403-1-git-send-email-shawn.lin@rock-chips.com> <1524207555-165403-2-git-send-email-shawn.lin@rock-chips.com> From: Ulf Hansson Date: Mon, 23 Apr 2018 11:06:00 +0200 Message-ID: Subject: Re: [PATCH v3 2/2] mmc: core: Add tunable delay before detecting card after card is inserted Content-Type: text/plain; charset="UTF-8" To: Shawn Lin Cc: Rob Herring , Linus Walleij , "linux-mmc@vger.kernel.org" , devicetree@vger.kernel.org List-ID: On 20 April 2018 at 08:59, Shawn Lin wrote: > Allow to use tunable delay before detecting card after card is inserted, > which either comes from firmware node, or comes from debounce value > passed on to mmc_gpiod_request_cd(). If the platform doesn't support > debounce, then we fall back to use the debounce period as the delay, > otherwise, it behaves the same as before that a HW debounce(if set) plus > a 200ms hardcode delay before detecting the card. > > Signed-off-by: Shawn Lin > > --- > > Changes in v3: None > Changes in v2: > - doesn't introduce new agrument for mmc_gpiod_request_cd and drop > the change for host drivers > > drivers/mmc/core/host.c | 7 +++++-- > drivers/mmc/core/slot-gpio.c | 9 +++++++-- > 2 files changed, 12 insertions(+), 4 deletions(-) > > diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c > index 64b03d6..d281cbf 100644 > --- a/drivers/mmc/core/host.c > +++ b/drivers/mmc/core/host.c > @@ -179,7 +179,7 @@ static void mmc_retune_timer(struct timer_list *t) > int mmc_of_parse(struct mmc_host *host) > { > struct device *dev = host->parent; > - u32 bus_width, drv_type; > + u32 bus_width, drv_type, cd_delay_ms; > int ret; > bool cd_cap_invert, cd_gpio_invert = false; > bool ro_cap_invert, ro_gpio_invert = false; > @@ -230,11 +230,14 @@ int mmc_of_parse(struct mmc_host *host) > } else { > cd_cap_invert = device_property_read_bool(dev, "cd-inverted"); > > + if (device_property_read_u32(dev, "cd-delay-ms", &cd_delay_ms)) > + cd_delay_ms = 200; > + > if (device_property_read_bool(dev, "broken-cd")) > host->caps |= MMC_CAP_NEEDS_POLL; > > ret = mmc_gpiod_request_cd(host, "cd", 0, true, > - 0, &cd_gpio_invert); > + cd_delay_ms, &cd_gpio_invert); > if (!ret) > dev_info(host->parent, "Got CD GPIO\n"); > else if (ret != -ENOENT && ret != -ENOSYS) > diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c > index 31f7dbb..2ef41be 100644 > --- a/drivers/mmc/core/slot-gpio.c > +++ b/drivers/mmc/core/slot-gpio.c > @@ -28,15 +28,17 @@ struct mmc_gpio { > irqreturn_t (*cd_gpio_isr)(int irq, void *dev_id); > char *ro_label; > char cd_label[0]; > + u32 cd_delay_ms; > }; > > static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id) > { > /* Schedule a card detection after a debounce timeout */ > struct mmc_host *host = dev_id; > + struct mmc_gpio *ctx = host->slot.handler_priv; > > host->trigger_card_event = true; > - mmc_detect_change(host, msecs_to_jiffies(200)); > + mmc_detect_change(host, msecs_to_jiffies(ctx->cd_delay_ms)); > > return IRQ_HANDLED; > } > @@ -49,6 +51,7 @@ int mmc_gpio_alloc(struct mmc_host *host) > > if (ctx) { > ctx->ro_label = ctx->cd_label + len; > + ctx->cd_delay_ms = 200; > snprintf(ctx->cd_label, len, "%s cd", dev_name(host->parent)); > snprintf(ctx->ro_label, len, "%s ro", dev_name(host->parent)); > host->slot.handler_priv = ctx; > @@ -239,6 +242,8 @@ int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio, > * @debounce: debounce time in microseconds > * @gpio_invert: will return whether the GPIO line is inverted or not, set > * to NULL to ignore > + * @cd_delay_ms: delay time in ms before detecting card after card insert > + * event This looks like a leftover from earlier versions... > * > * Use this function in place of mmc_gpio_request_cd() to use the GPIO > * descriptor API. Note that it must be called prior to mmc_add_host() > @@ -261,7 +266,7 @@ int mmc_gpiod_request_cd(struct mmc_host *host, const char *con_id, > if (debounce) { > ret = gpiod_set_debounce(desc, debounce); > if (ret < 0) > - return ret; > + ctx->cd_delay_ms = debounce; > } > > if (gpio_invert) > -- > 1.9.1 > > Besides the minor thing above, this looks good to me. Kind regards Uffe