diff options
author | Guennadi Liakhovetski <g.liakhovetski@gmx.de> | 2012-05-01 14:27:25 (GMT) |
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committer | Chris Ball <cjb@laptop.org> | 2012-07-21 04:02:17 (GMT) |
commit | befe4048d8d20483a62636e20f3dbffebf85a1c1 (patch) | |
tree | 31bec106a3a2f4956cc1fd4a1fa4b465d31bddb9 /drivers/mmc/core | |
parent | 5c08d7fae0815cd163a98e05c8d94fc0de77ff67 (diff) | |
download | linux-befe4048d8d20483a62636e20f3dbffebf85a1c1.tar.xz |
mmc: add CD GPIO polling support to slot functions
A simple extension of mmc slot functions add support for CD GPIO polling
for cases where the GPIO cannot produce interrupts, or where this is not
desired for some reason.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc/core')
-rw-r--r-- | drivers/mmc/core/slot-gpio.c | 56 |
1 files changed, 43 insertions, 13 deletions
diff --git a/drivers/mmc/core/slot-gpio.c b/drivers/mmc/core/slot-gpio.c index 468e5a0..92cba02 100644 --- a/drivers/mmc/core/slot-gpio.c +++ b/drivers/mmc/core/slot-gpio.c @@ -18,7 +18,7 @@ #include <linux/slab.h> struct mmc_gpio { - unsigned int cd_gpio; + int cd_gpio; char cd_label[0]; }; @@ -29,6 +29,18 @@ static irqreturn_t mmc_gpio_cd_irqt(int irq, void *dev_id) return IRQ_HANDLED; } +int mmc_gpio_get_cd(struct mmc_host *host) +{ + struct mmc_gpio *ctx = host->slot.handler_priv; + + if (!ctx || !gpio_is_valid(ctx->cd_gpio)) + return -ENOSYS; + + return !gpio_get_value_cansleep(ctx->cd_gpio) ^ + !!(host->caps2 & MMC_CAP2_CD_ACTIVE_HIGH); +} +EXPORT_SYMBOL(mmc_gpio_get_cd); + int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio) { size_t len = strlen(dev_name(host->parent)) + 4; @@ -36,9 +48,6 @@ int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio) int irq = gpio_to_irq(gpio); int ret; - if (irq < 0) - return irq; - ctx = kmalloc(sizeof(*ctx) + len, GFP_KERNEL); if (!ctx) return -ENOMEM; @@ -49,20 +58,32 @@ int mmc_gpio_request_cd(struct mmc_host *host, unsigned int gpio) if (ret < 0) goto egpioreq; - ret = request_threaded_irq(irq, NULL, mmc_gpio_cd_irqt, + /* + * Even if gpio_to_irq() returns a valid IRQ number, the platform might + * still prefer to poll, e.g., because that IRQ number is already used + * by another unit and cannot be shared. + */ + if (irq >= 0 && host->caps & MMC_CAP_NEEDS_POLL) + irq = -EINVAL; + + if (irq >= 0) { + ret = request_threaded_irq(irq, NULL, mmc_gpio_cd_irqt, IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_ONESHOT, ctx->cd_label, host); - if (ret < 0) - goto eirqreq; + if (ret < 0) + irq = ret; + } - ctx->cd_gpio = gpio; host->slot.cd_irq = irq; + + if (irq < 0) + host->caps |= MMC_CAP_NEEDS_POLL; + + ctx->cd_gpio = gpio; host->slot.handler_priv = ctx; return 0; -eirqreq: - gpio_free(gpio); egpioreq: kfree(ctx); return ret; @@ -72,12 +93,21 @@ EXPORT_SYMBOL(mmc_gpio_request_cd); void mmc_gpio_free_cd(struct mmc_host *host) { struct mmc_gpio *ctx = host->slot.handler_priv; + int gpio; - if (!ctx) + if (!ctx || !gpio_is_valid(ctx->cd_gpio)) return; - free_irq(host->slot.cd_irq, host); - gpio_free(ctx->cd_gpio); + if (host->slot.cd_irq >= 0) { + free_irq(host->slot.cd_irq, host); + host->slot.cd_irq = -EINVAL; + } + + gpio = ctx->cd_gpio; + ctx->cd_gpio = -EINVAL; + + gpio_free(gpio); + host->slot.handler_priv = NULL; kfree(ctx); } EXPORT_SYMBOL(mmc_gpio_free_cd); |