From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Horman Date: Sat, 16 Feb 2013 06:05:26 +0000 Subject: Re: [PATCH v4 03/13] mmc: provide a standard MMC device-tree binding parser centrally Message-Id: <20130216060526.GA20785@verge.net.au> List-Id: References: <1360941242-18153-1-git-send-email-g.liakhovetski@gmx.de> <1360941242-18153-4-git-send-email-g.liakhovetski@gmx.de> In-Reply-To: <1360941242-18153-4-git-send-email-g.liakhovetski@gmx.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Guennadi Liakhovetski Cc: linux-mmc@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, linux-sh@vger.kernel.org, Magnus Damm , Arnd Bergmann , Markus Pargmann On Fri, Feb 15, 2013 at 04:13:52PM +0100, Guennadi Liakhovetski wrote: > MMC defines a number of standard DT bindings. Having each driver parse > them individually adds code redundancy and is error prone. Provide a > standard function to unify the parsing. After all drivers are converted > to using it instead of their own parsers, this function can be integrated > into mmc_alloc_host(). > > Cc: Markus Pargmann > Signed-off-by: Guennadi Liakhovetski > --- > > v4: make the bus-width property optional to match a recent change to > mmc.txt, use of_property_read_bool() to obtain a boolean value of a DT > property, add comments. > > drivers/mmc/core/host.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/mmc/host.h | 1 + > 2 files changed, 109 insertions(+), 0 deletions(-) > > diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c > index ee2e16b..daa2ed1 100644 > --- a/drivers/mmc/core/host.c > +++ b/drivers/mmc/core/host.c > @@ -15,6 +15,8 @@ > #include > #include > #include > +#include > +#include > #include > #include > #include > @@ -23,6 +25,7 @@ > > #include > #include > +#include > > #include "core.h" > #include "host.h" > @@ -295,6 +298,111 @@ static inline void mmc_host_clk_sysfs_init(struct mmc_host *host) > #endif > > /** > + * mmc_of_parse() - parse host's device-tree node > + * @host: host, whose node should be parsed. > + * > + * To keep the rest of the MMC subsystem unaware of the fact, whether DT has > + * been used to to instantiate and configure this host instance or not, we > + * parse the properties and set respective generic mmc-host flags and > + * parameters. > + */ > +void mmc_of_parse(struct mmc_host *host) > +{ > + struct device_node *np; > + u32 bus_width; > + bool explicit_inv_wp, gpio_inv_wp = false; > + enum of_gpio_flags flags; > + int len, ret, gpio; > + > + if (!host->parent || !host->parent->of_node) > + return; > + > + np = host->parent->of_node; > + > + /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */ > + if (of_property_read_u32_array(np, "bus-width", &bus_width, 1) < 0) > + dev_dbg(host->parent, > + "\"bus-width\" property is missing, assuming 1 bit.\n"); > + > + switch (bus_width) { kbuild tells me that gcc thinks that bus_width is used without being initialised here. Assuming that of_property_read_u32_array always initialises bus_width if it returns zero then perhaps it would be worth considering using uninitialized_var(). > + case 8: > + host->caps |= MMC_CAP_8_BIT_DATA; > + /* Hosts, capable of 8-bit transfers can also do 4 bits */ > + case 4: > + host->caps |= MMC_CAP_4_BIT_DATA; > + break; > + case 1: > + break; > + default: > + dev_err(host->parent, > + "Invalid \"bus-width\" value %ud!\n", bus_width); > + } > + > + /* f_max is obtained from the optional "max-frequency" property */ > + of_property_read_u32_array(np, "max-frequency", &host->f_max, 1); > + > + /* > + * Configure CD and WP pins. They are both by default active low to > + * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the > + * mmc-gpio helpers are used to attach, configure and use them. If > + * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH > + * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the > + * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability > + * is set. If the "non-removable" property is found, the > + * MMC_CAP_NONREMOVABLE capability is set and no card-detection > + * configuration is performed. > + */ > + > + /* Parse Card Detection */ > + if (of_find_property(np, "non-removable", &len)) { > + host->caps |= MMC_CAP_NONREMOVABLE; > + } else { > + bool explicit_inv_cd, gpio_inv_cd = false; > + > + explicit_inv_cd = of_property_read_bool(np, "cd-inverted"); > + > + if (of_find_property(np, "broken-cd", &len)) > + host->caps |= MMC_CAP_NEEDS_POLL; > + > + gpio = of_get_named_gpio_flags(np, "cd-gpios", 0, &flags); > + if (gpio_is_valid(gpio)) { > + if (!(flags & OF_GPIO_ACTIVE_LOW)) > + gpio_inv_cd = true; > + > + ret = mmc_gpio_request_cd(host, gpio); > + if (ret < 0) > + dev_err(host->parent, > + "Failed to request CD GPIO #%d: %d!\n", > + gpio, ret); > + else > + dev_info(host->parent, "Got CD GPIO #%d.\n", > + gpio); > + } > + > + if (explicit_inv_cd ^ gpio_inv_cd) > + host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH; > + } > + > + /* Parse Write Protection */ > + explicit_inv_wp = of_property_read_bool(np, "wp-inverted"); > + > + gpio = of_get_named_gpio_flags(np, "wp-gpios", 0, &flags); > + if (gpio_is_valid(gpio)) { > + if (!(flags & OF_GPIO_ACTIVE_LOW)) > + gpio_inv_wp = true; > + > + ret = mmc_gpio_request_ro(host, gpio); > + if (ret < 0) > + dev_err(host->parent, > + "Failed to request WP GPIO: %d!\n", ret); > + } > + if (explicit_inv_wp ^ gpio_inv_wp) > + host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH; > +} > + > +EXPORT_SYMBOL(mmc_of_parse); > + > +/** > * mmc_alloc_host - initialise the per-host structure. > * @extra: sizeof private data structure > * @dev: pointer to host device model structure > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h > index 61a10c1..13c0c8d 100644 > --- a/include/linux/mmc/host.h > +++ b/include/linux/mmc/host.h > @@ -345,6 +345,7 @@ extern struct mmc_host *mmc_alloc_host(int extra, struct device *); > extern int mmc_add_host(struct mmc_host *); > extern void mmc_remove_host(struct mmc_host *); > extern void mmc_free_host(struct mmc_host *); > +void mmc_of_parse(struct mmc_host *host); > > static inline void *mmc_priv(struct mmc_host *host) > { > -- > 1.7.2.5 > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Horman Subject: Re: [PATCH v4 03/13] mmc: provide a standard MMC device-tree binding parser centrally Date: Sat, 16 Feb 2013 15:05:26 +0900 Message-ID: <20130216060526.GA20785@verge.net.au> References: <1360941242-18153-1-git-send-email-g.liakhovetski@gmx.de> <1360941242-18153-4-git-send-email-g.liakhovetski@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1360941242-18153-4-git-send-email-g.liakhovetski@gmx.de> Sender: linux-sh-owner@vger.kernel.org To: Guennadi Liakhovetski Cc: linux-mmc@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, linux-sh@vger.kernel.org, Magnus Damm , Arnd Bergmann , Markus Pargmann List-Id: devicetree@vger.kernel.org On Fri, Feb 15, 2013 at 04:13:52PM +0100, Guennadi Liakhovetski wrote: > MMC defines a number of standard DT bindings. Having each driver parse > them individually adds code redundancy and is error prone. Provide a > standard function to unify the parsing. After all drivers are converted > to using it instead of their own parsers, this function can be integrated > into mmc_alloc_host(). > > Cc: Markus Pargmann > Signed-off-by: Guennadi Liakhovetski > --- > > v4: make the bus-width property optional to match a recent change to > mmc.txt, use of_property_read_bool() to obtain a boolean value of a DT > property, add comments. > > drivers/mmc/core/host.c | 108 ++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/mmc/host.h | 1 + > 2 files changed, 109 insertions(+), 0 deletions(-) > > diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c > index ee2e16b..daa2ed1 100644 > --- a/drivers/mmc/core/host.c > +++ b/drivers/mmc/core/host.c > @@ -15,6 +15,8 @@ > #include > #include > #include > +#include > +#include > #include > #include > #include > @@ -23,6 +25,7 @@ > > #include > #include > +#include > > #include "core.h" > #include "host.h" > @@ -295,6 +298,111 @@ static inline void mmc_host_clk_sysfs_init(struct mmc_host *host) > #endif > > /** > + * mmc_of_parse() - parse host's device-tree node > + * @host: host, whose node should be parsed. > + * > + * To keep the rest of the MMC subsystem unaware of the fact, whether DT has > + * been used to to instantiate and configure this host instance or not, we > + * parse the properties and set respective generic mmc-host flags and > + * parameters. > + */ > +void mmc_of_parse(struct mmc_host *host) > +{ > + struct device_node *np; > + u32 bus_width; > + bool explicit_inv_wp, gpio_inv_wp = false; > + enum of_gpio_flags flags; > + int len, ret, gpio; > + > + if (!host->parent || !host->parent->of_node) > + return; > + > + np = host->parent->of_node; > + > + /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */ > + if (of_property_read_u32_array(np, "bus-width", &bus_width, 1) < 0) > + dev_dbg(host->parent, > + "\"bus-width\" property is missing, assuming 1 bit.\n"); > + > + switch (bus_width) { kbuild tells me that gcc thinks that bus_width is used without being initialised here. Assuming that of_property_read_u32_array always initialises bus_width if it returns zero then perhaps it would be worth considering using uninitialized_var(). > + case 8: > + host->caps |= MMC_CAP_8_BIT_DATA; > + /* Hosts, capable of 8-bit transfers can also do 4 bits */ > + case 4: > + host->caps |= MMC_CAP_4_BIT_DATA; > + break; > + case 1: > + break; > + default: > + dev_err(host->parent, > + "Invalid \"bus-width\" value %ud!\n", bus_width); > + } > + > + /* f_max is obtained from the optional "max-frequency" property */ > + of_property_read_u32_array(np, "max-frequency", &host->f_max, 1); > + > + /* > + * Configure CD and WP pins. They are both by default active low to > + * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the > + * mmc-gpio helpers are used to attach, configure and use them. If > + * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH > + * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the > + * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability > + * is set. If the "non-removable" property is found, the > + * MMC_CAP_NONREMOVABLE capability is set and no card-detection > + * configuration is performed. > + */ > + > + /* Parse Card Detection */ > + if (of_find_property(np, "non-removable", &len)) { > + host->caps |= MMC_CAP_NONREMOVABLE; > + } else { > + bool explicit_inv_cd, gpio_inv_cd = false; > + > + explicit_inv_cd = of_property_read_bool(np, "cd-inverted"); > + > + if (of_find_property(np, "broken-cd", &len)) > + host->caps |= MMC_CAP_NEEDS_POLL; > + > + gpio = of_get_named_gpio_flags(np, "cd-gpios", 0, &flags); > + if (gpio_is_valid(gpio)) { > + if (!(flags & OF_GPIO_ACTIVE_LOW)) > + gpio_inv_cd = true; > + > + ret = mmc_gpio_request_cd(host, gpio); > + if (ret < 0) > + dev_err(host->parent, > + "Failed to request CD GPIO #%d: %d!\n", > + gpio, ret); > + else > + dev_info(host->parent, "Got CD GPIO #%d.\n", > + gpio); > + } > + > + if (explicit_inv_cd ^ gpio_inv_cd) > + host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH; > + } > + > + /* Parse Write Protection */ > + explicit_inv_wp = of_property_read_bool(np, "wp-inverted"); > + > + gpio = of_get_named_gpio_flags(np, "wp-gpios", 0, &flags); > + if (gpio_is_valid(gpio)) { > + if (!(flags & OF_GPIO_ACTIVE_LOW)) > + gpio_inv_wp = true; > + > + ret = mmc_gpio_request_ro(host, gpio); > + if (ret < 0) > + dev_err(host->parent, > + "Failed to request WP GPIO: %d!\n", ret); > + } > + if (explicit_inv_wp ^ gpio_inv_wp) > + host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH; > +} > + > +EXPORT_SYMBOL(mmc_of_parse); > + > +/** > * mmc_alloc_host - initialise the per-host structure. > * @extra: sizeof private data structure > * @dev: pointer to host device model structure > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h > index 61a10c1..13c0c8d 100644 > --- a/include/linux/mmc/host.h > +++ b/include/linux/mmc/host.h > @@ -345,6 +345,7 @@ extern struct mmc_host *mmc_alloc_host(int extra, struct device *); > extern int mmc_add_host(struct mmc_host *); > extern void mmc_remove_host(struct mmc_host *); > extern void mmc_free_host(struct mmc_host *); > +void mmc_of_parse(struct mmc_host *host); > > static inline void *mmc_priv(struct mmc_host *host) > { > -- > 1.7.2.5 >