From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: [PATCH v4 04/10] eeprom: Add a simple EEPROM framework for eeprom consumers Date: Tue, 7 Apr 2015 11:45:33 -0700 Message-ID: <20150407184533.GA10278@codeaurora.org> References: <1427752492-17039-1-git-send-email-srinivas.kandagatla@linaro.org> <1427752670-17219-1-git-send-email-srinivas.kandagatla@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1427752670-17219-1-git-send-email-srinivas.kandagatla@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: Srinivas Kandagatla Cc: linux-arm-kernel@lists.infradead.org, Maxime Ripard , Rob Herring , Kumar Gala , Mark Brown , s.hauer@pengutronix.de, Greg Kroah-Hartman , linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org, arnd@arndb.de List-Id: linux-arm-msm@vger.kernel.org On 03/30, Srinivas Kandagatla wrote: > @@ -130,6 +138,37 @@ static struct class eeprom_class = { > .dev_release = eeprom_release, > }; > > +static int of_eeprom_match(struct device *dev, const void *eeprom_np) > +{ > + return dev->of_node == eeprom_np; > +} > + > +static struct eeprom_device *of_eeprom_find(struct device_node *eeprom_np) > +{ > + struct device *d; > + > + if (!eeprom_np) > + return NULL; > + > + d = class_find_device(&eeprom_class, NULL, eeprom_np, of_eeprom_match); > + > + return d ? to_eeprom(d) : NULL; > +} > + > +static int eeprom_match(struct device *dev, const void *data) > +{ > + return !strcmp(dev_name(dev), (const char *)data); Is this cast necessary? > +} > + > +static struct eeprom_device *eeprom_find(const char *name) > +{ > + struct device *d; > + > + d = class_find_device(&eeprom_class, NULL, (void *)name, eeprom_match); Is this cast necessary? > + > + return d ? to_eeprom(d) : NULL; > +} > + > /** > * eeprom_register(): Register a eeprom device for given eeprom. > * Also creates an binary entry in /sys/class/eeprom/name-id/eeprom > + > +/** > + * eeprom_cell_get(): Get eeprom cell of device form a given eeprom name s/form/from/ > + * and blocks. > + * > + * @ename: eeprom device name that needs to be looked-up. > + * @blocks: eeprom blocks containing offset and length information. > + * @nblocks: number of eeprom blocks. > + * > + * The return value will be an ERR_PTR() on error or a valid pointer > + * to a struct eeprom_cell. The eeprom_cell will be freed by the > + * eeprom_cell_put(). > + */ > +struct eeprom_cell *eeprom_cell_get(const char *ename, > + struct eeprom_block *blocks, int nblocks) > +{ > + return __eeprom_cell_get(NULL, ename, blocks, nblocks); > +} > +EXPORT_SYMBOL_GPL(eeprom_cell_get); > + > +/** > + * of_eeprom_cell_get(): Get eeprom cell of device form a given index s/form/from/ > + * > + * @dev node: Device tree node that uses the eeprom cell > + * @index: eeprom index in eeproms property. > + * > + * The return value will be an ERR_PTR() on error or a valid pointer > + * to a struct eeprom_cell. The eeprom_cell will be freed by the > + * eeprom_cell_put(). > + */ > +struct eeprom_cell *of_eeprom_cell_get(struct device_node *np, const char *name) > +{ > + struct device_node *cell_np; > + > + cell_np = of_parse_phandle(np, name, 0); > + if (!cell_np) > + return ERR_PTR(-EINVAL); > + > + return __eeprom_cell_get(cell_np, NULL, NULL, 0); > +} > +EXPORT_SYMBOL_GPL(of_eeprom_cell_get); > + > diff --git a/include/linux/eeprom-consumer.h b/include/linux/eeprom-consumer.h > new file mode 100644 > index 0000000..effa417 > --- /dev/null > +++ b/include/linux/eeprom-consumer.h > @@ -0,0 +1,61 @@ > +/* > + * EEPROM framework consumer. > + * > + * Copyright (C) 2015 Srinivas Kandagatla > + * Copyright (C) 2013 Maxime Ripard > + * > + * This file is licensed under the terms of the GNU General Public > + * License version 2. This program is licensed "as is" without any > + * warranty of any kind, whether express or implied. > + */ > + > +#ifndef _LINUX_EEPROM_CONSUMER_H > +#define _LINUX_EEPROM_CONSUMER_H > + > +struct eeprom_cell; > + > +struct eeprom_block { > + loff_t offset; > + size_t count; > +}; > +#if IS_ENABLED(CONFIG_EEPROM) > +struct eeprom_cell *eeprom_cell_get(const char *ename, > + struct eeprom_block *blocks, int nblocks); > +void eeprom_cell_put(struct eeprom_cell *cell); > +char *eeprom_cell_read(struct eeprom_cell *cell, ssize_t *len); > +int eeprom_cell_write(struct eeprom_cell *cell, const char *buf, ssize_t len); [...] > + > +#if IS_ENABLED(CONFIG_EEPROM) && IS_ENABLED(CONFIG_OF) > +struct eeprom_cell *of_eeprom_cell_get(struct device_node *dev, > + const char *property); > +#else > +static inline struct eeprom_cell *of_eeprom_cell_get(struct device_node *np, > + const char *property) > +{ > + return ERR_PTR(-ENOSYS); > +} > +#endif > +#endif /* ifndef _LINUX_EEPROM_CONSUMER_H */ Do you have an overview of how to use these APIs? Maybe some Documentation/ is in order? I'm mostly interested in how the blocks array is supposed to work and how this hooks up to drivers that are using DT. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project