diff mbox series

[v2,11/16] nvmem: add support for cell info

Message ID 20180907100750.14564-12-brgl@bgdev.pl (mailing list archive)
State Superseded, archived
Headers show
Series nvmem: rework of the subsystem for non-DT users | expand

Commit Message

Bartosz Golaszewski Sept. 7, 2018, 10:07 a.m. UTC 
From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

Add new structs and routines allowing users to define nvmem cells from
machine code. This global list of entries is parsed when a provider
is registered and cells are associated with the relevant nvmem_device
struct.

A possible improvement for the future is to allow users to register
cell tables after the nvmem provider has been registered by updating
the cell list at each call to nvmem_(add|del)_cell_table().

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 MAINTAINERS                   |  1 +
 drivers/nvmem/core.c          | 97 ++++++++++++++++++++++++++++++++++-
 include/linux/nvmem-machine.h | 41 +++++++++++++++
 3 files changed, 138 insertions(+), 1 deletion(-)
 create mode 100644 include/linux/nvmem-machine.h

Comments

Srinivas Kandagatla Sept. 10, 2018, 7:32 a.m. UTC | #1 
On 07/09/18 11:07, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> 
> Add new structs and routines allowing users to define nvmem cells from
> machine code. This global list of entries is parsed when a provider
> is registered and cells are associated with the relevant nvmem_device
> struct.
> 
> A possible improvement for the future is to allow users to register
> cell tables after the nvmem provider has been registered by updating
> the cell list at each call to nvmem_(add|del)_cell_table().
> 
> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> ---
>   MAINTAINERS                   |  1 +
>   drivers/nvmem/core.c          | 97 ++++++++++++++++++++++++++++++++++-

I see some of this code is removed in first patch and added back here, I 
dont really see a value in doing this in a single series of patchset.

I would recommend "[PATCH v2 01/16] nvmem: remove unused APIs" and this 
patch to be merged.

>   include/linux/nvmem-machine.h | 41 +++++++++++++++
>   3 files changed, 138 insertions(+), 1 deletion(-)
>   create mode 100644 include/linux/nvmem-machine.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 9ad052aeac39..a520924bf0a9 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -10391,6 +10391,7 @@ F:	drivers/nvmem/
>   F:	Documentation/devicetree/bindings/nvmem/
>   F:	Documentation/ABI/stable/sysfs-bus-nvmem
>   F:	include/linux/nvmem-consumer.h
> +F:	include/linux/nvmem-machine.h
>   F:	include/linux/nvmem-provider.h
>   
>   NXP SGTL5000 DRIVER
> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
> index 17307015905a..854baa0559a1 100644
> --- a/drivers/nvmem/core.c
> +++ b/drivers/nvmem/core.c
...
>    *
> diff --git a/include/linux/nvmem-machine.h b/include/linux/nvmem-machine.h
> new file mode 100644
> index 000000000000..1e199dfaacab
> --- /dev/null
> +++ b/include/linux/nvmem-machine.h

This should go in nvmem-consumer.h, I don't think we should add header 
files for each usecase. These are nvmem consumers so lets put them in 
correct header file.


--srini
Boris Brezillon Sept. 10, 2018, 7:36 a.m. UTC | #2 
Hi Srinivas,

On Mon, 10 Sep 2018 08:32:21 +0100
Srinivas Kandagatla <srinivas.kandagatla@linaro.org> wrote:

> On 07/09/18 11:07, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > 
> > Add new structs and routines allowing users to define nvmem cells from
> > machine code. This global list of entries is parsed when a provider
> > is registered and cells are associated with the relevant nvmem_device
> > struct.
> > 
> > A possible improvement for the future is to allow users to register
> > cell tables after the nvmem provider has been registered by updating
> > the cell list at each call to nvmem_(add|del)_cell_table().
> > 
> > Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> > ---
> >   MAINTAINERS                   |  1 +
> >   drivers/nvmem/core.c          | 97 ++++++++++++++++++++++++++++++++++-  
> 
> I see some of this code is removed in first patch and added back here, I 
> dont really see a value in doing this in a single series of patchset.
> 
> I would recommend "[PATCH v2 01/16] nvmem: remove unused APIs" and this 
> patch to be merged.
> 
> >   include/linux/nvmem-machine.h | 41 +++++++++++++++
> >   3 files changed, 138 insertions(+), 1 deletion(-)
> >   create mode 100644 include/linux/nvmem-machine.h
> > 
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 9ad052aeac39..a520924bf0a9 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -10391,6 +10391,7 @@ F:	drivers/nvmem/
> >   F:	Documentation/devicetree/bindings/nvmem/
> >   F:	Documentation/ABI/stable/sysfs-bus-nvmem
> >   F:	include/linux/nvmem-consumer.h
> > +F:	include/linux/nvmem-machine.h
> >   F:	include/linux/nvmem-provider.h
> >   
> >   NXP SGTL5000 DRIVER
> > diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
> > index 17307015905a..854baa0559a1 100644
> > --- a/drivers/nvmem/core.c
> > +++ b/drivers/nvmem/core.c  
> ...
> >    *
> > diff --git a/include/linux/nvmem-machine.h b/include/linux/nvmem-machine.h
> > new file mode 100644
> > index 000000000000..1e199dfaacab
> > --- /dev/null
> > +++ b/include/linux/nvmem-machine.h  
> 
> This should go in nvmem-consumer.h, I don't think we should add header 
> files for each usecase. These are nvmem consumers so lets put them in 
> correct header file.

Actually no, it should go in nvmem-provider.h. Consumer should not be
allowed to define cells, only reference existing ones.

Regards,

Boris
Srinivas Kandagatla Sept. 10, 2018, 8:53 a.m. UTC | #3 
On 10/09/18 08:36, Boris Brezillon wrote:
>>> --- /dev/null
>>> +++ b/include/linux/nvmem-machine.h
>> This should go in nvmem-consumer.h, I don't think we should add header
>> files for each usecase. These are nvmem consumers so lets put them in
>> correct header file.
> Actually no, it should go in nvmem-provider.h. Consumer should not be
> allowed to define cells, only reference existing ones.The usecase can be provider and consumer.
In arm machine use case it is a consumer and it other use cases this can 
be a provider.

I agree with you, It makes more sense to be in nvmem-provider.h

thanks,
srini
> 
> Regards,
> 
> Boris
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 9ad052aeac39..a520924bf0a9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10391,6 +10391,7 @@  F:	drivers/nvmem/
 F:	Documentation/devicetree/bindings/nvmem/
 F:	Documentation/ABI/stable/sysfs-bus-nvmem
 F:	include/linux/nvmem-consumer.h
+F:	include/linux/nvmem-machine.h
 F:	include/linux/nvmem-provider.h
 
 NXP SGTL5000 DRIVER
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 17307015905a..854baa0559a1 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -21,6 +21,7 @@ 
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/nvmem-consumer.h>
+#include <linux/nvmem-machine.h>
 #include <linux/nvmem-provider.h>
 #include <linux/of.h>
 #include <linux/slab.h>
@@ -58,6 +59,9 @@  struct nvmem_cell {
 static DEFINE_MUTEX(nvmem_mutex);
 static DEFINE_IDA(nvmem_ida);
 
+static DEFINE_MUTEX(nvmem_cell_mutex);
+static LIST_HEAD(nvmem_cell_tables);
+
 static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
@@ -341,6 +345,66 @@  static int nvmem_setup_compat(struct nvmem_device *nvmem,
 	return 0;
 }
 
+static struct nvmem_cell *
+nvmem_cell_from_cell_info(struct nvmem_device *nvmem,
+			  struct nvmem_cell_info *info)
+{
+	struct nvmem_cell *cell;
+
+	cell = kzalloc(sizeof(*cell), GFP_KERNEL);
+	if (!cell)
+		return ERR_PTR(-ENOMEM);
+
+	cell->nvmem = nvmem;
+	cell->offset = info->offset;
+	cell->bytes = info->bytes;
+	cell->name = info->name;
+	cell->bit_offset = info->bit_offset;
+	cell->nbits = info->nbits;
+
+	if (cell->nbits)
+		cell->bytes = DIV_ROUND_UP(cell->nbits + cell->bit_offset,
+					   BITS_PER_BYTE);
+
+	if (!IS_ALIGNED(cell->offset, nvmem->stride)) {
+		dev_err(&nvmem->dev,
+			"cell %s unaligned to nvmem stride %d\n",
+			cell->name, nvmem->stride);
+		kfree(cell);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return cell;
+}
+
+static int nvmem_add_cells_from_list(struct nvmem_device *nvmem)
+{
+	struct nvmem_cell_table *table;
+	struct nvmem_cell_info *info;
+	struct nvmem_cell *cell;
+	int rval = 0, i;
+
+	mutex_lock(&nvmem_cell_mutex);
+	list_for_each_entry(table, &nvmem_cell_tables, node) {
+		if (strcmp(nvmem_dev_name(nvmem), table->nvmem_name) == 0) {
+			for (i = 0; i < table->ncells; i++) {
+				info = &table->cells[i];
+				cell = nvmem_cell_from_cell_info(nvmem, info);
+				if (IS_ERR(cell)) {
+					rval = PTR_ERR(cell);
+					goto out;
+				}
+
+				nvmem_cell_add(cell);
+			}
+		}
+	}
+
+out:
+	mutex_unlock(&nvmem_cell_mutex);
+	return rval;
+}
+
 /**
  * nvmem_register_notifier() - Register a notifier block for nvmem events.
  *
@@ -447,13 +511,18 @@  struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 	}
 
 	INIT_LIST_HEAD(&nvmem->cells);
+	rval = nvmem_add_cells_from_list(nvmem);
+	if (rval)
+		goto err_teardown_compat;
 
 	rval = blocking_notifier_call_chain(&nvmem_notifier, NVMEM_ADD, nvmem);
 	if (rval)
-		goto err_teardown_compat;
+		goto err_remove_cells;
 
 	return nvmem;
 
+err_remove_cells:
+	nvmem_device_remove_all_cells(nvmem);
 err_teardown_compat:
 	if (config->compat)
 		device_remove_bin_file(nvmem->base_dev, &nvmem->eeprom);
@@ -1179,6 +1248,32 @@  int nvmem_device_write(struct nvmem_device *nvmem,
 }
 EXPORT_SYMBOL_GPL(nvmem_device_write);
 
+/**
+ * nvmem_add_cell_table() - register a table of cell info entries
+ *
+ * @table: table of cell info entries
+ */
+void nvmem_add_cell_table(struct nvmem_cell_table *table)
+{
+	mutex_lock(&nvmem_cell_mutex);
+	list_add_tail(&table->node, &nvmem_cell_tables);
+	mutex_unlock(&nvmem_cell_mutex);
+}
+EXPORT_SYMBOL_GPL(nvmem_add_cell_table);
+
+/**
+ * nvmem_del_cell_table() - remove a previously registered cell info table
+ *
+ * @table: table of cell info entries
+ */
+void nvmem_del_cell_table(struct nvmem_cell_table *table)
+{
+	mutex_lock(&nvmem_cell_mutex);
+	list_del(&table->node);
+	mutex_unlock(&nvmem_cell_mutex);
+}
+EXPORT_SYMBOL_GPL(nvmem_del_cell_table);
+
 /**
  * nvmem_dev_name() - Get the name of a given nvmem device.
  *
diff --git a/include/linux/nvmem-machine.h b/include/linux/nvmem-machine.h
new file mode 100644
index 000000000000..1e199dfaacab
--- /dev/null
+++ b/include/linux/nvmem-machine.h
@@ -0,0 +1,41 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * nvmem framework machine code bindings
+ *
+ * Copyright (C) 2018 Bartosz Golaszewski <bgolaszewski@baylibre.com>
+ */
+
+#ifndef _LINUX_NVMEM_MACHINE_H
+#define _LINUX_NVMEM_MACHINE_H
+
+#include <linux/nvmem-provider.h>
+#include <linux/list.h>
+
+struct nvmem_cell_info {
+	const char		*name;
+	unsigned int		offset;
+	unsigned int		bytes;
+	unsigned int		bit_offset;
+	unsigned int		nbits;
+};
+
+struct nvmem_cell_table {
+	const char		*nvmem_name;
+	struct nvmem_cell_info	*cells;
+	size_t			ncells;
+	struct list_head	node;
+};
+
+#if IS_ENABLED(CONFIG_NVMEM)
+
+void nvmem_add_cell_table(struct nvmem_cell_table *table);
+void nvmem_del_cell_table(struct nvmem_cell_table *table);
+
+#else /* CONFIG_NVMEM */
+
+static inline void nvmem_add_cell_table(struct nvmem_cell_table *table) {}
+static inline void nvmem_del_cell_table(struct nvmem_cell_table *table) {}
+
+#endif /* CONFIG_NVMEM */
+
+#endif  /* ifndef _LINUX_NVMEM_MACHINE_H */