diff options
| author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2018-10-05 15:42:56 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-10-11 12:12:54 +0200 |
| commit | a02509f301c68c9a7f01d75d7d326f7a9b81a630 (patch) | |
| tree | 4e2783a20585a89abf094b38c593cb38a8472bb3 | |
| parent | d279a38020d2483cb75f5f82f5e4ab5f73bc94f2 (diff) | |
stm class: Factor out default framing protocol
The STP framing pattern that the stm class implicitly applies to the
data payload is, in fact, a protocol. This patch moves the relevant code
out of the stm core into its own driver module.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/hwtracing/stm/Kconfig | 15 | ||||
| -rw-r--r-- | drivers/hwtracing/stm/Makefile | 4 | ||||
| -rw-r--r-- | drivers/hwtracing/stm/p_basic.c | 48 |
3 files changed, 67 insertions, 0 deletions
diff --git a/drivers/hwtracing/stm/Kconfig b/drivers/hwtracing/stm/Kconfig index 723e2d90083d..262e7891fb97 100644 --- a/drivers/hwtracing/stm/Kconfig +++ b/drivers/hwtracing/stm/Kconfig @@ -11,6 +11,21 @@ config STM if STM +config STM_PROTO_BASIC + tristate "Basic STM framing protocol driver" + default CONFIG_STM + help + This is a simple framing protocol for sending data over STM + devices. This was the protocol that the STM framework used + exclusively until the MIPI SyS-T support was added. Use this + driver for compatibility with your existing STM setup. + + The receiving side only needs to be able to decode the MIPI + STP protocol in order to extract the data. + + If you want to be able to use the basic protocol or want the + backwards compatibility for your existing setup, say Y. + config STM_DUMMY tristate "Dummy STM driver" help diff --git a/drivers/hwtracing/stm/Makefile b/drivers/hwtracing/stm/Makefile index effc19e5190f..1571de66eca4 100644 --- a/drivers/hwtracing/stm/Makefile +++ b/drivers/hwtracing/stm/Makefile @@ -3,6 +3,10 @@ obj-$(CONFIG_STM) += stm_core.o stm_core-y := core.o policy.o +obj-$(CONFIG_STM_PROTO_BASIC) += stm_p_basic.o + +stm_p_basic-y := p_basic.o + obj-$(CONFIG_STM_DUMMY) += dummy_stm.o obj-$(CONFIG_STM_SOURCE_CONSOLE) += stm_console.o diff --git a/drivers/hwtracing/stm/p_basic.c b/drivers/hwtracing/stm/p_basic.c new file mode 100644 index 000000000000..8980a6a5fd6c --- /dev/null +++ b/drivers/hwtracing/stm/p_basic.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Basic framing protocol for STM devices. + * Copyright (c) 2018, Intel Corporation. + */ + +#include <linux/module.h> +#include <linux/device.h> +#include <linux/stm.h> +#include "stm.h" + +static ssize_t basic_write(struct stm_data *data, struct stm_output *output, + unsigned int chan, const char *buf, size_t count) +{ + unsigned int c = output->channel + chan; + unsigned int m = output->master; + const unsigned char nil = 0; + ssize_t sz; + + sz = stm_data_write(data, m, c, true, buf, count); + if (sz > 0) + data->packet(data, m, c, STP_PACKET_FLAG, 0, 0, &nil); + + return sz; +} + +static const struct stm_protocol_driver basic_pdrv = { + .owner = THIS_MODULE, + .name = "p_basic", + .write = basic_write, +}; + +static int basic_stm_init(void) +{ + return stm_register_protocol(&basic_pdrv); +} + +static void basic_stm_exit(void) +{ + stm_unregister_protocol(&basic_pdrv); +} + +module_init(basic_stm_init); +module_exit(basic_stm_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Basic STM framing protocol driver"); +MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>"); |