// SPDX-License-Identifier: GPL-2.0
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/*
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* A dummy STM device for stm/stm_source class testing.
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* Copyright (c) 2014, Intel Corporation.
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*
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* STM class implements generic infrastructure for System Trace Module devices
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* as defined in MIPI STPv2 specification.
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*/
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#undef DEBUG
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/stm.h>
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#include <uapi/linux/stm.h>
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static ssize_t notrace
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dummy_stm_packet(struct stm_data *stm_data, unsigned int master,
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unsigned int channel, unsigned int packet, unsigned int flags,
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unsigned int size, const unsigned char *payload)
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{
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#ifdef DEBUG
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u64 pl = 0;
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if (payload)
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pl = *(u64 *)payload;
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if (size < 8)
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pl &= (1ull << (size * 8)) - 1;
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trace_printk("[%u:%u] [pkt: %x/%x] (%llx)\n", master, channel,
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packet, size, pl);
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#endif
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return size;
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}
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#define DUMMY_STM_MAX 32
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static struct stm_data dummy_stm[DUMMY_STM_MAX];
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static int nr_dummies = 4;
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module_param(nr_dummies, int, 0400);
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static unsigned int fail_mode;
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module_param(fail_mode, int, 0600);
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static unsigned int master_min;
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module_param(master_min, int, 0400);
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static unsigned int master_max = STP_MASTER_MAX;
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module_param(master_max, int, 0400);
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static unsigned int nr_channels = STP_CHANNEL_MAX;
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module_param(nr_channels, int, 0400);
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static int dummy_stm_link(struct stm_data *data, unsigned int master,
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unsigned int channel)
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{
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if (fail_mode && (channel & fail_mode))
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return -EINVAL;
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return 0;
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}
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static int dummy_stm_init(void)
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{
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int i, ret = -ENOMEM;
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if (nr_dummies < 0 || nr_dummies > DUMMY_STM_MAX)
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return -EINVAL;
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if (master_min > master_max ||
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master_max > STP_MASTER_MAX ||
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nr_channels > STP_CHANNEL_MAX)
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return -EINVAL;
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for (i = 0; i < nr_dummies; i++) {
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dummy_stm[i].name = kasprintf(GFP_KERNEL, "dummy_stm.%d", i);
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if (!dummy_stm[i].name)
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goto fail_unregister;
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dummy_stm[i].sw_start = master_min;
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dummy_stm[i].sw_end = master_max;
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dummy_stm[i].sw_nchannels = nr_channels;
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dummy_stm[i].packet = dummy_stm_packet;
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dummy_stm[i].link = dummy_stm_link;
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ret = stm_register_device(NULL, &dummy_stm[i], THIS_MODULE);
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if (ret)
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goto fail_free;
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}
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return 0;
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fail_unregister:
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for (i--; i >= 0; i--) {
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stm_unregister_device(&dummy_stm[i]);
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fail_free:
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kfree(dummy_stm[i].name);
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}
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return ret;
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}
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static void dummy_stm_exit(void)
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{
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int i;
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for (i = 0; i < nr_dummies; i++) {
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stm_unregister_device(&dummy_stm[i]);
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kfree(dummy_stm[i].name);
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}
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}
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module_init(dummy_stm_init);
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module_exit(dummy_stm_exit);
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MODULE_LICENSE("GPL v2");
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MODULE_DESCRIPTION("dummy_stm device");
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MODULE_AUTHOR("Alexander Shishkin <alexander.shishkin@linux.intel.com>");
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