LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Bartosz Golaszewski <brgl@bgdev.pl>
To: Jonathan Corbet <corbet@lwn.net>, Sekhar Nori <nsekhar@ti.com>,
	Kevin Hilman <khilman@kernel.org>,
	Russell King <linux@armlinux.org.uk>,
	Arnd Bergmann <arnd@arndb.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	David Woodhouse <dwmw2@infradead.org>,
	Brian Norris <computersforpeace@gmail.com>,
	Boris Brezillon <boris.brezillon@bootlin.com>,
	Marek Vasut <marek.vasut@gmail.com>,
	Richard Weinberger <richard@nod.at>,
	Grygorii Strashko <grygorii.strashko@ti.com>,
	"David S . Miller" <davem@davemloft.net>,
	Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
	Naren <naren.kernel@gmail.com>,
	Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Lukas Wunner <lukas@wunner.de>,
	Dan Carpenter <dan.carpenter@oracle.com>,
	Florian Fainelli <f.fainelli@gmail.com>,
	Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>,
	Sven Van Asbroeck <svendev@arcx.com>,
	Paolo Abeni <pabeni@redhat.com>, Alban Bedel <albeu@free.fr>,
	Rob Herring <robh@kernel.org>,
	David Lechner <david@lechnology.com>,
	Andrew Lunn <andrew@lunn.ch>
Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org,
	linux-mtd@lists.infradead.org, linux-omap@vger.kernel.org,
	netdev@vger.kernel.org,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>
Subject: [PATCH v2 01/29] nvmem: add support for cell lookups
Date: Fri, 10 Aug 2018 10:04:58 +0200
Message-ID: <20180810080526.27207-2-brgl@bgdev.pl> (raw)
In-Reply-To: <20180810080526.27207-1-brgl@bgdev.pl>

From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

We can currently only register nvmem cells from device tree or by
manually calling nvmem_add_cells(). The latter options however forces
users to make sure that the nvmem provider with which the cells are
associated is registered before the call.

This patch proposes a new solution inspired by other frameworks that
offer resource lookups (GPIO, PWM etc.). It adds functions that allow
machine code to register nvmem lookup which are later lazily used to
add corresponding nvmem cells and remove them if no longer needed.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
---
 drivers/nvmem/core.c           | 77 +++++++++++++++++++++++++++++++++-
 include/linux/nvmem-consumer.h |  6 +++
 include/linux/nvmem-provider.h | 10 +++++
 3 files changed, 92 insertions(+), 1 deletion(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 514d1dfc5630..329ea5b8f809 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -62,6 +62,9 @@ static DEFINE_IDA(nvmem_ida);
 static LIST_HEAD(nvmem_cells);
 static DEFINE_MUTEX(nvmem_cells_mutex);
 
+static LIST_HEAD(nvmem_cell_lookups);
+static DEFINE_MUTEX(nvmem_lookup_mutex);
+
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 static struct lock_class_key eeprom_lock_key;
 #endif
@@ -247,6 +250,41 @@ static const struct attribute_group *nvmem_ro_root_dev_groups[] = {
 	NULL,
 };
 
+/**
+ * nvmem_add_lookup_table() - register a number of nvmem cell lookup entries
+ *
+ * @lookup: array of nvmem cell lookup entries
+ * @nentries: number of lookup entries in the array
+ */
+void nvmem_add_lookup_table(struct nvmem_cell_lookup *lookup, size_t nentries)
+{
+	int i;
+
+	mutex_lock(&nvmem_lookup_mutex);
+	for (i = 0; i < nentries; i++)
+		list_add_tail(&lookup[i].list, &nvmem_cell_lookups);
+	mutex_unlock(&nvmem_lookup_mutex);
+}
+EXPORT_SYMBOL_GPL(nvmem_add_lookup_table);
+
+/**
+ * nvmem_del_lookup_table() - unregister a set of previously added nvmem cell
+ *                            lookup entries
+ *
+ * @lookup: array of nvmem cell lookup entries
+ * @nentries: number of lookup entries in the array
+ */
+void nvmem_del_lookup_table(struct nvmem_cell_lookup *lookup, size_t nentries)
+{
+	int i;
+
+	mutex_lock(&nvmem_lookup_mutex);
+	for (i = 0; i < nentries; i++)
+		list_del(&lookup[i].list);
+	mutex_unlock(&nvmem_lookup_mutex);
+}
+EXPORT_SYMBOL_GPL(nvmem_del_lookup_table);
+
 static void nvmem_release(struct device *dev)
 {
 	struct nvmem_device *nvmem = to_nvmem_device(dev);
@@ -916,6 +954,39 @@ struct nvmem_cell *of_nvmem_cell_get(struct device_node *np,
 EXPORT_SYMBOL_GPL(of_nvmem_cell_get);
 #endif
 
+static struct nvmem_cell *nvmem_cell_from_lookup(const char *cell_id)
+{
+	struct nvmem_cell *cell = ERR_PTR(-ENOENT);
+	struct nvmem_cell_lookup *lookup;
+	struct nvmem_device *nvmem;
+	int rc;
+
+	mutex_lock(&nvmem_lookup_mutex);
+
+	list_for_each_entry(lookup, &nvmem_cell_lookups, list) {
+		if (strcmp(cell_id, lookup->info.name) == 0) {
+			nvmem = nvmem_find(lookup->nvmem_name);
+			if (!nvmem) {
+				cell = ERR_PTR(-EPROBE_DEFER);
+				goto out;
+			}
+
+			rc = nvmem_add_cells(nvmem, &lookup->info, 1);
+			if (rc) {
+				cell = ERR_PTR(rc);
+				goto out;
+			}
+
+			cell = nvmem_cell_get_from_list(cell_id);
+			break;
+		}
+	}
+
+out:
+	mutex_unlock(&nvmem_lookup_mutex);
+	return cell;
+}
+
 /**
  * nvmem_cell_get() - Get nvmem cell of device form a given cell name
  *
@@ -940,7 +1011,11 @@ struct nvmem_cell *nvmem_cell_get(struct device *dev, const char *cell_id)
 	if (!cell_id)
 		return ERR_PTR(-EINVAL);
 
-	return nvmem_cell_get_from_list(cell_id);
+	cell = nvmem_cell_get_from_list(cell_id);
+	if (!IS_ERR(cell) || PTR_ERR(cell) == -EPROBE_DEFER)
+		return cell;
+
+	return nvmem_cell_from_lookup(cell_id);
 }
 EXPORT_SYMBOL_GPL(nvmem_cell_get);
 
diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h
index 4e85447f7860..f4b5d3186e94 100644
--- a/include/linux/nvmem-consumer.h
+++ b/include/linux/nvmem-consumer.h
@@ -29,6 +29,12 @@ struct nvmem_cell_info {
 	unsigned int		nbits;
 };
 
+struct nvmem_cell_lookup {
+	struct nvmem_cell_info	info;
+	struct list_head	list;
+	const char		*nvmem_name;
+};
+
 #if IS_ENABLED(CONFIG_NVMEM)
 
 /* Cell based interface */
diff --git a/include/linux/nvmem-provider.h b/include/linux/nvmem-provider.h
index 24def6ad09bb..6a17d722062b 100644
--- a/include/linux/nvmem-provider.h
+++ b/include/linux/nvmem-provider.h
@@ -17,6 +17,7 @@
 
 struct nvmem_device;
 struct nvmem_cell_info;
+struct nvmem_cell_lookup;
 typedef int (*nvmem_reg_read_t)(void *priv, unsigned int offset,
 				void *val, size_t bytes);
 typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset,
@@ -72,6 +73,9 @@ struct nvmem_config {
 struct nvmem_device *nvmem_register(const struct nvmem_config *cfg);
 int nvmem_unregister(struct nvmem_device *nvmem);
 
+void nvmem_add_lookup_table(struct nvmem_cell_lookup *lookup, size_t nentries);
+void nvmem_del_lookup_table(struct nvmem_cell_lookup *lookup, size_t nentries);
+
 struct nvmem_device *devm_nvmem_register(struct device *dev,
 					 const struct nvmem_config *cfg);
 
@@ -92,6 +96,12 @@ static inline int nvmem_unregister(struct nvmem_device *nvmem)
 	return -ENOSYS;
 }
 
+static inline void
+nvmem_add_lookup_table(struct nvmem_cell_lookup *lookup, size_t nentries) {}
+
+static inline void
+nvmem_del_lookup_table(struct nvmem_cell_lookup *lookup, size_t nentries) {}
+
 static inline struct nvmem_device *
 devm_nvmem_register(struct device *dev, const struct nvmem_config *c)
 {
-- 
2.18.0


  reply index

Thread overview: 92+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-10  8:04 [PATCH v2 00/29] at24: remove at24_platform_data Bartosz Golaszewski
2018-08-10  8:04 ` Bartosz Golaszewski [this message]
2018-08-24 15:08   ` [PATCH v2 01/29] nvmem: add support for cell lookups Boris Brezillon
2018-08-24 15:27     ` Andrew Lunn
2018-08-25  6:27       ` Boris Brezillon
2018-08-27  8:56         ` Bartosz Golaszewski
2018-08-27  9:00           ` Boris Brezillon
2018-08-27 13:37             ` Bartosz Golaszewski
2018-08-27 14:01               ` Boris Brezillon
2018-08-28 10:15               ` Srinivas Kandagatla
2018-08-28 11:56                 ` Bartosz Golaszewski
2018-08-28 13:45                   ` Srinivas Kandagatla
2018-08-28 14:41                     ` Bartosz Golaszewski
2018-08-28 14:48                       ` Srinivas Kandagatla
2018-08-28 14:53                       ` Boris Brezillon
2018-08-28 15:09                         ` Srinivas Kandagatla
2018-08-10  8:04 ` [PATCH v2 02/29] Documentation: nvmem: document lookup entries Bartosz Golaszewski
2018-08-31 20:30   ` Brian Norris
2018-09-01 13:11     ` Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 03/29] nvmem: add a notifier chain Bartosz Golaszewski
2018-08-10  8:33   ` Srinivas Kandagatla
2018-08-10  8:05 ` [PATCH v2 04/29] nvmem: provide nvmem_dev_name() Bartosz Golaszewski
2018-08-10  8:10   ` Srinivas Kandagatla
2018-08-10  8:05 ` [PATCH v2 05/29] nvmem: remove the name field from struct nvmem_device Bartosz Golaszewski
2018-08-10  8:33   ` Srinivas Kandagatla
2018-08-10  8:05 ` [PATCH v2 06/29] mtd: Add support for reading MTD devices via the nvmem API Bartosz Golaszewski
2018-08-17 16:27   ` Boris Brezillon
2018-08-19 11:31     ` Alban
2018-08-19 16:46       ` Boris Brezillon
2018-08-20 10:43         ` Srinivas Kandagatla
2018-08-20 18:20           ` Boris Brezillon
2018-08-20 18:50             ` Bartosz Golaszewski
2018-08-20 19:06               ` Boris Brezillon
2018-08-20 21:27             ` Alban
2018-08-21  5:07               ` Boris Brezillon
2018-08-21  9:50             ` Srinivas Kandagatla
2018-08-21  9:56               ` Boris Brezillon
2018-08-21 10:11                 ` Srinivas Kandagatla
2018-08-21 10:43                   ` Boris Brezillon
2018-08-21 11:39               ` Alban
2018-08-21 12:00                 ` Srinivas Kandagatla
2018-08-21 13:01                   ` Boris Brezillon
2018-08-23 10:29                     ` Alban
2018-08-24 14:39                       ` Boris Brezillon
2018-08-28 10:20                       ` Srinivas Kandagatla
2018-08-20 22:53         ` Alban
2018-08-21  5:44           ` Boris Brezillon
2018-08-21  9:38             ` Srinivas Kandagatla
2018-08-21 11:31               ` Boris Brezillon
2018-08-21 13:34                 ` Srinivas Kandagatla
2018-08-21 13:37                   ` Srinivas Kandagatla
2018-08-21 13:57                     ` Boris Brezillon
2018-08-21 12:27             ` Alban
2018-08-21 12:57               ` Boris Brezillon
2018-08-21 13:57                 ` Alban
2018-08-21 14:26                   ` Boris Brezillon
2018-08-21 14:33                     ` Srinivas Kandagatla
2018-08-10  8:05 ` [PATCH v2 07/29] ARM: davinci: dm365-evm: use nvmem lookup for mac address Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 08/29] ARM: davinci: dm644-evm: " Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 09/29] ARM: davinci: dm646x-evm: " Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 10/29] ARM: davinci: da830-evm: " Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 11/29] ARM: davinci: mityomapl138: add nvmem cells lookup entries Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 12/29] ARM: davinci: da850-evm: use nvmem lookup for mac address Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 13/29] ARM: davinci: da850-evm: remove unnecessary include Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 14/29] net: simplify eth_platform_get_mac_address() Bartosz Golaszewski
2018-08-10 14:39   ` Andy Shevchenko
2018-08-10 16:17     ` Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 15/29] net: split eth_platform_get_mac_address() into subroutines Bartosz Golaszewski
2018-08-31 19:54   ` Brian Norris
2018-08-10  8:05 ` [PATCH v2 16/29] net: add support for nvmem to eth_platform_get_mac_address() Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 17/29] net: davinci_emac: use eth_platform_get_mac_address() Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 18/29] ARM: davinci: da850-evm: remove dead MTD code Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 19/29] ARM: davinci: mityomapl138: don't read the MAC address from machine code Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 20/29] ARM: davinci: dm365-evm: use device properties for at24 eeprom Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 21/29] ARM: davinci: da830-evm: " Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 22/29] ARM: davinci: dm644x-evm: " Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 23/29] ARM: davinci: dm646x-evm: " Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 24/29] ARM: davinci: sffsdr: fix the at24 eeprom device name Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 25/29] ARM: davinci: sffsdr: use device properties for at24 eeprom Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 26/29] ARM: davinci: remove dead code related to MAC address reading Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 27/29] ARM: davinci: mityomapl138: use nvmem notifiers Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 28/29] ARM: davinci: mityomapl138: use device properties for at24 eeprom Bartosz Golaszewski
2018-08-10  8:05 ` [PATCH v2 29/29] eeprom: at24: kill at24_platform_data Bartosz Golaszewski
2018-08-10  8:41 ` [PATCH v2 00/29] at24: remove at24_platform_data Srinivas Kandagatla
2018-08-31 19:46 ` Brian Norris
2018-10-03 20:15   ` Bartosz Golaszewski
2018-10-03 20:30     ` Lukas Wunner
2018-10-03 21:04     ` Florian Fainelli
2018-10-04 11:06       ` Bartosz Golaszewski
2018-10-04 13:58         ` Arnd Bergmann
2018-10-04 14:35           ` Sowmini Varadhan
2018-10-04 14:38             ` Arnd Bergmann

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20180810080526.27207-2-brgl@bgdev.pl \
    --to=brgl@bgdev.pl \
    --cc=akpm@linux-foundation.org \
    --cc=albeu@free.fr \
    --cc=andrew@lunn.ch \
    --cc=arnd@arndb.de \
    --cc=bgolaszewski@baylibre.com \
    --cc=boris.brezillon@bootlin.com \
    --cc=computersforpeace@gmail.com \
    --cc=corbet@lwn.net \
    --cc=dan.carpenter@oracle.com \
    --cc=davem@davemloft.net \
    --cc=david@lechnology.com \
    --cc=dwmw2@infradead.org \
    --cc=f.fainelli@gmail.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=grygorii.strashko@ti.com \
    --cc=ivan.khoronzhuk@linaro.org \
    --cc=khilman@kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-i2c@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mtd@lists.infradead.org \
    --cc=linux-omap@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=lukas@wunner.de \
    --cc=marek.vasut@gmail.com \
    --cc=mchehab+samsung@kernel.org \
    --cc=naren.kernel@gmail.com \
    --cc=netdev@vger.kernel.org \
    --cc=nsekhar@ti.com \
    --cc=pabeni@redhat.com \
    --cc=richard@nod.at \
    --cc=robh@kernel.org \
    --cc=srinivas.kandagatla@linaro.org \
    --cc=svendev@arcx.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org linux-kernel@archiver.kernel.org
	public-inbox-index lkml


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox