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Message-Id: <F7D77D88-214B-48FC-AAA7-05A76483D017@fuzziesquirrel.com>
Date: Tue, 2 May 2017 01:25:22 -0400
From: Brad Bishop <bradleyb@...ziesquirrel.com>
To: Christopher Bostic <cbostic@...ux.vnet.ibm.com>
Cc: robh+dt@...nel.org, mark.rutland@....com, linux@...linux.org.uk,
rostedt@...dmis.org, mingo@...hat.com, gregkh@...uxfoundation.org,
devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
andrew@...id.au, alistair@...ple.id.au,
linux-kernel@...r.kernel.org, Jeremy Kerr <jk@...abs.org>,
"Edward A . James" <eajames@...ibm.com>, benh@...nel.crashing.org,
joel@....id.au
Subject: Re: [v6,10/23] drivers/fsi: Add device read/write/peek API
> On Apr 10, 2017, at 3:46 PM, Christopher Bostic <cbostic@...ux.vnet.ibm.com> wrote:
>
> From: Jeremy Kerr <jk@...abs.org>
>
> This change introduces the fsi device API: simple read, write and peek
> accessors for the devices' address spaces.
>
> Includes contributions from Chris Bostic <cbostic@...ux.vnet.ibm.com>
> and Edward A. James <eajames@...ibm.com>.
>
> Signed-off-by: Edward A. James <eajames@...ibm.com>
> Signed-off-by: Jeremy Kerr <jk@...abs.org>
> Signed-off-by: Chris Bostic <cbostic@...ux.vnet.ibm.com>
> Signed-off-by: Joel Stanley <joel@....id.au>
> ---
> drivers/fsi/fsi-core.c | 33 +++++++++++++++++++++++++++++++++
> include/linux/fsi.h | 7 ++++++-
> 2 files changed, 39 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c
> index a8faa89..4da0b030 100644
> --- a/drivers/fsi/fsi-core.c
> +++ b/drivers/fsi/fsi-core.c
> @@ -32,6 +32,8 @@
> #define FSI_SLAVE_CONF_CRC_MASK 0x0000000f
> #define FSI_SLAVE_CONF_DATA_BITS 28
>
> +#define FSI_PEEK_BASE 0x410
> +
> static const int engine_page_size = 0x400;
>
> #define FSI_SLAVE_BASE 0x800
> @@ -73,9 +75,40 @@ static int fsi_master_read(struct fsi_master *master, int link,
> uint8_t slave_id, uint32_t addr, void *val, size_t size);
> static int fsi_master_write(struct fsi_master *master, int link,
> uint8_t slave_id, uint32_t addr, const void *val, size_t size);
> +static int fsi_slave_read(struct fsi_slave *slave, uint32_t addr,
> + void *val, size_t size);
> +static int fsi_slave_write(struct fsi_slave *slave, uint32_t addr,
> + const void *val, size_t size);
>
> /* FSI endpoint-device support */
>
> +int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val,
> + size_t size)
> +{
> + if (addr > dev->size || size > dev->size || addr > dev->size - size)
> + return -EINVAL;
> +
> + return fsi_slave_read(dev->slave, dev->addr + addr, val, size);
> +}
> +EXPORT_SYMBOL_GPL(fsi_device_read);
> +
> +int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val,
> + size_t size)
> +{
> + if (addr > dev->size || size > dev->size || addr > dev->size - size)
> + return -EINVAL;
> +
> + return fsi_slave_write(dev->slave, dev->addr + addr, val, size);
> +}
> +EXPORT_SYMBOL_GPL(fsi_device_write);
> +
> +int fsi_device_peek(struct fsi_device *dev, void *val)
> +{
> + uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t));
> +
> + return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t));
> +}
> +
> static void fsi_device_release(struct device *_device)
> {
> struct fsi_device *device = to_fsi_dev(_device);
> diff --git a/include/linux/fsi.h b/include/linux/fsi.h
> index efa55ba..66bce48 100644
> --- a/include/linux/fsi.h
> +++ b/include/linux/fsi.h
> @@ -27,6 +27,12 @@ struct fsi_device {
> uint32_t size;
> };
>
> +extern int fsi_device_read(struct fsi_device *dev, uint32_t addr,
> + void *val, size_t size);
> +extern int fsi_device_write(struct fsi_device *dev, uint32_t addr,
> + const void *val, size_t size);
> +extern int fsi_device_peek(struct fsi_device *dev, void *val);
> +
> struct fsi_device_id {
> u8 engine_type;
> u8 version;
> @@ -40,7 +46,6 @@ struct fsi_device_id {
> #define FSI_DEVICE_VERSIONED(t, v) \
> .engine_type = (t), .version = (v),
>
> -
> struct fsi_driver {
> struct device_driver drv;
> const struct fsi_device_id *id_table;
I wrote a driver using this API. It seems to be suitable enough.
Acked-by: Brad Bishop <bradleyb@...ziesquirrel.com>
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