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766 lines
18 KiB
766 lines
18 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
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* HSI core. |
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* |
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* Copyright (C) 2010 Nokia Corporation. All rights reserved. |
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* |
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* Contact: Carlos Chinea <[email protected]> |
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*/ |
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#include <linux/hsi/hsi.h> |
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#include <linux/compiler.h> |
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#include <linux/list.h> |
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#include <linux/kobject.h> |
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#include <linux/slab.h> |
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#include <linux/string.h> |
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#include <linux/notifier.h> |
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#include <linux/of.h> |
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#include <linux/of_device.h> |
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#include "hsi_core.h" |
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|
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static ssize_t modalias_show(struct device *dev, |
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struct device_attribute *a __maybe_unused, char *buf) |
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{ |
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return sprintf(buf, "hsi:%s\n", dev_name(dev)); |
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} |
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static DEVICE_ATTR_RO(modalias); |
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|
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static struct attribute *hsi_bus_dev_attrs[] = { |
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&dev_attr_modalias.attr, |
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NULL, |
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}; |
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ATTRIBUTE_GROUPS(hsi_bus_dev); |
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|
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static int hsi_bus_uevent(struct device *dev, struct kobj_uevent_env *env) |
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{ |
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add_uevent_var(env, "MODALIAS=hsi:%s", dev_name(dev)); |
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|
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return 0; |
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} |
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|
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static int hsi_bus_match(struct device *dev, struct device_driver *driver) |
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{ |
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if (of_driver_match_device(dev, driver)) |
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return true; |
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|
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if (strcmp(dev_name(dev), driver->name) == 0) |
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return true; |
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|
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return false; |
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} |
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|
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static struct bus_type hsi_bus_type = { |
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.name = "hsi", |
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.dev_groups = hsi_bus_dev_groups, |
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.match = hsi_bus_match, |
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.uevent = hsi_bus_uevent, |
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}; |
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|
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static void hsi_client_release(struct device *dev) |
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{ |
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struct hsi_client *cl = to_hsi_client(dev); |
|
|
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kfree(cl->tx_cfg.channels); |
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kfree(cl->rx_cfg.channels); |
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kfree(cl); |
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} |
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|
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struct hsi_client *hsi_new_client(struct hsi_port *port, |
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struct hsi_board_info *info) |
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{ |
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struct hsi_client *cl; |
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size_t size; |
|
|
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cl = kzalloc(sizeof(*cl), GFP_KERNEL); |
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if (!cl) |
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goto err; |
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|
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cl->tx_cfg = info->tx_cfg; |
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if (cl->tx_cfg.channels) { |
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size = cl->tx_cfg.num_channels * sizeof(*cl->tx_cfg.channels); |
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cl->tx_cfg.channels = kmemdup(info->tx_cfg.channels, size, |
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GFP_KERNEL); |
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if (!cl->tx_cfg.channels) |
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goto err_tx; |
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} |
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|
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cl->rx_cfg = info->rx_cfg; |
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if (cl->rx_cfg.channels) { |
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size = cl->rx_cfg.num_channels * sizeof(*cl->rx_cfg.channels); |
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cl->rx_cfg.channels = kmemdup(info->rx_cfg.channels, size, |
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GFP_KERNEL); |
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if (!cl->rx_cfg.channels) |
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goto err_rx; |
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} |
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|
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cl->device.bus = &hsi_bus_type; |
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cl->device.parent = &port->device; |
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cl->device.release = hsi_client_release; |
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dev_set_name(&cl->device, "%s", info->name); |
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cl->device.platform_data = info->platform_data; |
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if (info->archdata) |
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cl->device.archdata = *info->archdata; |
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if (device_register(&cl->device) < 0) { |
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pr_err("hsi: failed to register client: %s\n", info->name); |
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put_device(&cl->device); |
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} |
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|
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return cl; |
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err_rx: |
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kfree(cl->tx_cfg.channels); |
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err_tx: |
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kfree(cl); |
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err: |
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return NULL; |
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} |
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EXPORT_SYMBOL_GPL(hsi_new_client); |
|
|
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static void hsi_scan_board_info(struct hsi_controller *hsi) |
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{ |
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struct hsi_cl_info *cl_info; |
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struct hsi_port *p; |
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|
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list_for_each_entry(cl_info, &hsi_board_list, list) |
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if (cl_info->info.hsi_id == hsi->id) { |
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p = hsi_find_port_num(hsi, cl_info->info.port); |
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if (!p) |
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continue; |
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hsi_new_client(p, &cl_info->info); |
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} |
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} |
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|
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#ifdef CONFIG_OF |
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static struct hsi_board_info hsi_char_dev_info = { |
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.name = "hsi_char", |
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}; |
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|
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static int hsi_of_property_parse_mode(struct device_node *client, char *name, |
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unsigned int *result) |
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{ |
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const char *mode; |
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int err; |
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|
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err = of_property_read_string(client, name, &mode); |
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if (err < 0) |
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return err; |
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|
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if (strcmp(mode, "stream") == 0) |
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*result = HSI_MODE_STREAM; |
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else if (strcmp(mode, "frame") == 0) |
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*result = HSI_MODE_FRAME; |
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else |
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return -EINVAL; |
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|
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return 0; |
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} |
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|
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static int hsi_of_property_parse_flow(struct device_node *client, char *name, |
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unsigned int *result) |
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{ |
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const char *flow; |
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int err; |
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|
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err = of_property_read_string(client, name, &flow); |
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if (err < 0) |
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return err; |
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|
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if (strcmp(flow, "synchronized") == 0) |
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*result = HSI_FLOW_SYNC; |
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else if (strcmp(flow, "pipeline") == 0) |
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*result = HSI_FLOW_PIPE; |
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else |
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return -EINVAL; |
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|
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return 0; |
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} |
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|
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static int hsi_of_property_parse_arb_mode(struct device_node *client, |
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char *name, unsigned int *result) |
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{ |
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const char *arb_mode; |
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int err; |
|
|
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err = of_property_read_string(client, name, &arb_mode); |
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if (err < 0) |
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return err; |
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|
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if (strcmp(arb_mode, "round-robin") == 0) |
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*result = HSI_ARB_RR; |
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else if (strcmp(arb_mode, "priority") == 0) |
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*result = HSI_ARB_PRIO; |
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else |
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return -EINVAL; |
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|
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return 0; |
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} |
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|
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static void hsi_add_client_from_dt(struct hsi_port *port, |
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struct device_node *client) |
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{ |
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struct hsi_client *cl; |
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struct hsi_channel channel; |
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struct property *prop; |
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char name[32]; |
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int length, cells, err, i, max_chan, mode; |
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|
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cl = kzalloc(sizeof(*cl), GFP_KERNEL); |
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if (!cl) |
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return; |
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|
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err = of_modalias_node(client, name, sizeof(name)); |
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if (err) |
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goto err; |
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|
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err = hsi_of_property_parse_mode(client, "hsi-mode", &mode); |
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if (err) { |
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err = hsi_of_property_parse_mode(client, "hsi-rx-mode", |
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&cl->rx_cfg.mode); |
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if (err) |
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goto err; |
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|
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err = hsi_of_property_parse_mode(client, "hsi-tx-mode", |
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&cl->tx_cfg.mode); |
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if (err) |
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goto err; |
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} else { |
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cl->rx_cfg.mode = mode; |
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cl->tx_cfg.mode = mode; |
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} |
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|
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err = of_property_read_u32(client, "hsi-speed-kbps", |
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&cl->tx_cfg.speed); |
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if (err) |
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goto err; |
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cl->rx_cfg.speed = cl->tx_cfg.speed; |
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|
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err = hsi_of_property_parse_flow(client, "hsi-flow", |
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&cl->rx_cfg.flow); |
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if (err) |
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goto err; |
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|
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err = hsi_of_property_parse_arb_mode(client, "hsi-arb-mode", |
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&cl->rx_cfg.arb_mode); |
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if (err) |
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goto err; |
|
|
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prop = of_find_property(client, "hsi-channel-ids", &length); |
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if (!prop) { |
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err = -EINVAL; |
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goto err; |
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} |
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|
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cells = length / sizeof(u32); |
|
|
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cl->rx_cfg.num_channels = cells; |
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cl->tx_cfg.num_channels = cells; |
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cl->rx_cfg.channels = kcalloc(cells, sizeof(channel), GFP_KERNEL); |
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if (!cl->rx_cfg.channels) { |
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err = -ENOMEM; |
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goto err; |
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} |
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|
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cl->tx_cfg.channels = kcalloc(cells, sizeof(channel), GFP_KERNEL); |
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if (!cl->tx_cfg.channels) { |
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err = -ENOMEM; |
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goto err2; |
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} |
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|
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max_chan = 0; |
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for (i = 0; i < cells; i++) { |
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err = of_property_read_u32_index(client, "hsi-channel-ids", i, |
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&channel.id); |
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if (err) |
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goto err3; |
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|
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err = of_property_read_string_index(client, "hsi-channel-names", |
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i, &channel.name); |
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if (err) |
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channel.name = NULL; |
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|
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if (channel.id > max_chan) |
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max_chan = channel.id; |
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|
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cl->rx_cfg.channels[i] = channel; |
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cl->tx_cfg.channels[i] = channel; |
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} |
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|
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cl->rx_cfg.num_hw_channels = max_chan + 1; |
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cl->tx_cfg.num_hw_channels = max_chan + 1; |
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|
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cl->device.bus = &hsi_bus_type; |
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cl->device.parent = &port->device; |
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cl->device.release = hsi_client_release; |
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cl->device.of_node = client; |
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|
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dev_set_name(&cl->device, "%s", name); |
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if (device_register(&cl->device) < 0) { |
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pr_err("hsi: failed to register client: %s\n", name); |
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put_device(&cl->device); |
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} |
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|
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return; |
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|
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err3: |
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kfree(cl->tx_cfg.channels); |
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err2: |
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kfree(cl->rx_cfg.channels); |
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err: |
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kfree(cl); |
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pr_err("hsi client: missing or incorrect of property: err=%d\n", err); |
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} |
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|
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void hsi_add_clients_from_dt(struct hsi_port *port, struct device_node *clients) |
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{ |
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struct device_node *child; |
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|
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/* register hsi-char device */ |
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hsi_new_client(port, &hsi_char_dev_info); |
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|
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for_each_available_child_of_node(clients, child) |
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hsi_add_client_from_dt(port, child); |
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} |
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EXPORT_SYMBOL_GPL(hsi_add_clients_from_dt); |
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#endif |
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|
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int hsi_remove_client(struct device *dev, void *data __maybe_unused) |
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{ |
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device_unregister(dev); |
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|
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(hsi_remove_client); |
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|
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static int hsi_remove_port(struct device *dev, void *data __maybe_unused) |
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{ |
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device_for_each_child(dev, NULL, hsi_remove_client); |
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device_unregister(dev); |
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|
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return 0; |
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} |
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|
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static void hsi_controller_release(struct device *dev) |
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{ |
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struct hsi_controller *hsi = to_hsi_controller(dev); |
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|
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kfree(hsi->port); |
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kfree(hsi); |
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} |
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|
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static void hsi_port_release(struct device *dev) |
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{ |
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kfree(to_hsi_port(dev)); |
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} |
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|
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/** |
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* hsi_port_unregister_clients - Unregister an HSI port |
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* @port: The HSI port to unregister |
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*/ |
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void hsi_port_unregister_clients(struct hsi_port *port) |
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{ |
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device_for_each_child(&port->device, NULL, hsi_remove_client); |
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} |
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EXPORT_SYMBOL_GPL(hsi_port_unregister_clients); |
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|
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/** |
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* hsi_unregister_controller - Unregister an HSI controller |
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* @hsi: The HSI controller to register |
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*/ |
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void hsi_unregister_controller(struct hsi_controller *hsi) |
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{ |
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device_for_each_child(&hsi->device, NULL, hsi_remove_port); |
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device_unregister(&hsi->device); |
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} |
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EXPORT_SYMBOL_GPL(hsi_unregister_controller); |
|
|
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/** |
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* hsi_register_controller - Register an HSI controller and its ports |
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* @hsi: The HSI controller to register |
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* |
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* Returns -errno on failure, 0 on success. |
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*/ |
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int hsi_register_controller(struct hsi_controller *hsi) |
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{ |
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unsigned int i; |
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int err; |
|
|
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err = device_add(&hsi->device); |
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if (err < 0) |
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return err; |
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for (i = 0; i < hsi->num_ports; i++) { |
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hsi->port[i]->device.parent = &hsi->device; |
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err = device_add(&hsi->port[i]->device); |
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if (err < 0) |
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goto out; |
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} |
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/* Populate HSI bus with HSI clients */ |
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hsi_scan_board_info(hsi); |
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|
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return 0; |
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out: |
|
while (i-- > 0) |
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device_del(&hsi->port[i]->device); |
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device_del(&hsi->device); |
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|
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return err; |
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} |
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EXPORT_SYMBOL_GPL(hsi_register_controller); |
|
|
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/** |
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* hsi_register_client_driver - Register an HSI client to the HSI bus |
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* @drv: HSI client driver to register |
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* |
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* Returns -errno on failure, 0 on success. |
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*/ |
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int hsi_register_client_driver(struct hsi_client_driver *drv) |
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{ |
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drv->driver.bus = &hsi_bus_type; |
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|
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return driver_register(&drv->driver); |
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} |
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EXPORT_SYMBOL_GPL(hsi_register_client_driver); |
|
|
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static inline int hsi_dummy_msg(struct hsi_msg *msg __maybe_unused) |
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{ |
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return 0; |
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} |
|
|
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static inline int hsi_dummy_cl(struct hsi_client *cl __maybe_unused) |
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{ |
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return 0; |
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} |
|
|
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/** |
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* hsi_put_controller - Free an HSI controller |
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* |
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* @hsi: Pointer to the HSI controller to freed |
|
* |
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* HSI controller drivers should only use this function if they need |
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* to free their allocated hsi_controller structures before a successful |
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* call to hsi_register_controller. Other use is not allowed. |
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*/ |
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void hsi_put_controller(struct hsi_controller *hsi) |
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{ |
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unsigned int i; |
|
|
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if (!hsi) |
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return; |
|
|
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for (i = 0; i < hsi->num_ports; i++) |
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if (hsi->port && hsi->port[i]) |
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put_device(&hsi->port[i]->device); |
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put_device(&hsi->device); |
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} |
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EXPORT_SYMBOL_GPL(hsi_put_controller); |
|
|
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/** |
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* hsi_alloc_controller - Allocate an HSI controller and its ports |
|
* @n_ports: Number of ports on the HSI controller |
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* @flags: Kernel allocation flags |
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* |
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* Return NULL on failure or a pointer to an hsi_controller on success. |
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*/ |
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struct hsi_controller *hsi_alloc_controller(unsigned int n_ports, gfp_t flags) |
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{ |
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struct hsi_controller *hsi; |
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struct hsi_port **port; |
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unsigned int i; |
|
|
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if (!n_ports) |
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return NULL; |
|
|
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hsi = kzalloc(sizeof(*hsi), flags); |
|
if (!hsi) |
|
return NULL; |
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port = kcalloc(n_ports, sizeof(*port), flags); |
|
if (!port) { |
|
kfree(hsi); |
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return NULL; |
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} |
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hsi->num_ports = n_ports; |
|
hsi->port = port; |
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hsi->device.release = hsi_controller_release; |
|
device_initialize(&hsi->device); |
|
|
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for (i = 0; i < n_ports; i++) { |
|
port[i] = kzalloc(sizeof(**port), flags); |
|
if (port[i] == NULL) |
|
goto out; |
|
port[i]->num = i; |
|
port[i]->async = hsi_dummy_msg; |
|
port[i]->setup = hsi_dummy_cl; |
|
port[i]->flush = hsi_dummy_cl; |
|
port[i]->start_tx = hsi_dummy_cl; |
|
port[i]->stop_tx = hsi_dummy_cl; |
|
port[i]->release = hsi_dummy_cl; |
|
mutex_init(&port[i]->lock); |
|
BLOCKING_INIT_NOTIFIER_HEAD(&port[i]->n_head); |
|
dev_set_name(&port[i]->device, "port%d", i); |
|
hsi->port[i]->device.release = hsi_port_release; |
|
device_initialize(&hsi->port[i]->device); |
|
} |
|
|
|
return hsi; |
|
out: |
|
hsi_put_controller(hsi); |
|
|
|
return NULL; |
|
} |
|
EXPORT_SYMBOL_GPL(hsi_alloc_controller); |
|
|
|
/** |
|
* hsi_free_msg - Free an HSI message |
|
* @msg: Pointer to the HSI message |
|
* |
|
* Client is responsible to free the buffers pointed by the scatterlists. |
|
*/ |
|
void hsi_free_msg(struct hsi_msg *msg) |
|
{ |
|
if (!msg) |
|
return; |
|
sg_free_table(&msg->sgt); |
|
kfree(msg); |
|
} |
|
EXPORT_SYMBOL_GPL(hsi_free_msg); |
|
|
|
/** |
|
* hsi_alloc_msg - Allocate an HSI message |
|
* @nents: Number of memory entries |
|
* @flags: Kernel allocation flags |
|
* |
|
* nents can be 0. This mainly makes sense for read transfer. |
|
* In that case, HSI drivers will call the complete callback when |
|
* there is data to be read without consuming it. |
|
* |
|
* Return NULL on failure or a pointer to an hsi_msg on success. |
|
*/ |
|
struct hsi_msg *hsi_alloc_msg(unsigned int nents, gfp_t flags) |
|
{ |
|
struct hsi_msg *msg; |
|
int err; |
|
|
|
msg = kzalloc(sizeof(*msg), flags); |
|
if (!msg) |
|
return NULL; |
|
|
|
if (!nents) |
|
return msg; |
|
|
|
err = sg_alloc_table(&msg->sgt, nents, flags); |
|
if (unlikely(err)) { |
|
kfree(msg); |
|
msg = NULL; |
|
} |
|
|
|
return msg; |
|
} |
|
EXPORT_SYMBOL_GPL(hsi_alloc_msg); |
|
|
|
/** |
|
* hsi_async - Submit an HSI transfer to the controller |
|
* @cl: HSI client sending the transfer |
|
* @msg: The HSI transfer passed to controller |
|
* |
|
* The HSI message must have the channel, ttype, complete and destructor |
|
* fields set beforehand. If nents > 0 then the client has to initialize |
|
* also the scatterlists to point to the buffers to write to or read from. |
|
* |
|
* HSI controllers relay on pre-allocated buffers from their clients and they |
|
* do not allocate buffers on their own. |
|
* |
|
* Once the HSI message transfer finishes, the HSI controller calls the |
|
* complete callback with the status and actual_len fields of the HSI message |
|
* updated. The complete callback can be called before returning from |
|
* hsi_async. |
|
* |
|
* Returns -errno on failure or 0 on success |
|
*/ |
|
int hsi_async(struct hsi_client *cl, struct hsi_msg *msg) |
|
{ |
|
struct hsi_port *port = hsi_get_port(cl); |
|
|
|
if (!hsi_port_claimed(cl)) |
|
return -EACCES; |
|
|
|
WARN_ON_ONCE(!msg->destructor || !msg->complete); |
|
msg->cl = cl; |
|
|
|
return port->async(msg); |
|
} |
|
EXPORT_SYMBOL_GPL(hsi_async); |
|
|
|
/** |
|
* hsi_claim_port - Claim the HSI client's port |
|
* @cl: HSI client that wants to claim its port |
|
* @share: Flag to indicate if the client wants to share the port or not. |
|
* |
|
* Returns -errno on failure, 0 on success. |
|
*/ |
|
int hsi_claim_port(struct hsi_client *cl, unsigned int share) |
|
{ |
|
struct hsi_port *port = hsi_get_port(cl); |
|
int err = 0; |
|
|
|
mutex_lock(&port->lock); |
|
if ((port->claimed) && (!port->shared || !share)) { |
|
err = -EBUSY; |
|
goto out; |
|
} |
|
if (!try_module_get(to_hsi_controller(port->device.parent)->owner)) { |
|
err = -ENODEV; |
|
goto out; |
|
} |
|
port->claimed++; |
|
port->shared = !!share; |
|
cl->pclaimed = 1; |
|
out: |
|
mutex_unlock(&port->lock); |
|
|
|
return err; |
|
} |
|
EXPORT_SYMBOL_GPL(hsi_claim_port); |
|
|
|
/** |
|
* hsi_release_port - Release the HSI client's port |
|
* @cl: HSI client which previously claimed its port |
|
*/ |
|
void hsi_release_port(struct hsi_client *cl) |
|
{ |
|
struct hsi_port *port = hsi_get_port(cl); |
|
|
|
mutex_lock(&port->lock); |
|
/* Allow HW driver to do some cleanup */ |
|
port->release(cl); |
|
if (cl->pclaimed) |
|
port->claimed--; |
|
BUG_ON(port->claimed < 0); |
|
cl->pclaimed = 0; |
|
if (!port->claimed) |
|
port->shared = 0; |
|
module_put(to_hsi_controller(port->device.parent)->owner); |
|
mutex_unlock(&port->lock); |
|
} |
|
EXPORT_SYMBOL_GPL(hsi_release_port); |
|
|
|
static int hsi_event_notifier_call(struct notifier_block *nb, |
|
unsigned long event, void *data __maybe_unused) |
|
{ |
|
struct hsi_client *cl = container_of(nb, struct hsi_client, nb); |
|
|
|
(*cl->ehandler)(cl, event); |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* hsi_register_port_event - Register a client to receive port events |
|
* @cl: HSI client that wants to receive port events |
|
* @handler: Event handler callback |
|
* |
|
* Clients should register a callback to be able to receive |
|
* events from the ports. Registration should happen after |
|
* claiming the port. |
|
* The handler can be called in interrupt context. |
|
* |
|
* Returns -errno on error, or 0 on success. |
|
*/ |
|
int hsi_register_port_event(struct hsi_client *cl, |
|
void (*handler)(struct hsi_client *, unsigned long)) |
|
{ |
|
struct hsi_port *port = hsi_get_port(cl); |
|
|
|
if (!handler || cl->ehandler) |
|
return -EINVAL; |
|
if (!hsi_port_claimed(cl)) |
|
return -EACCES; |
|
cl->ehandler = handler; |
|
cl->nb.notifier_call = hsi_event_notifier_call; |
|
|
|
return blocking_notifier_chain_register(&port->n_head, &cl->nb); |
|
} |
|
EXPORT_SYMBOL_GPL(hsi_register_port_event); |
|
|
|
/** |
|
* hsi_unregister_port_event - Stop receiving port events for a client |
|
* @cl: HSI client that wants to stop receiving port events |
|
* |
|
* Clients should call this function before releasing their associated |
|
* port. |
|
* |
|
* Returns -errno on error, or 0 on success. |
|
*/ |
|
int hsi_unregister_port_event(struct hsi_client *cl) |
|
{ |
|
struct hsi_port *port = hsi_get_port(cl); |
|
int err; |
|
|
|
WARN_ON(!hsi_port_claimed(cl)); |
|
|
|
err = blocking_notifier_chain_unregister(&port->n_head, &cl->nb); |
|
if (!err) |
|
cl->ehandler = NULL; |
|
|
|
return err; |
|
} |
|
EXPORT_SYMBOL_GPL(hsi_unregister_port_event); |
|
|
|
/** |
|
* hsi_event - Notifies clients about port events |
|
* @port: Port where the event occurred |
|
* @event: The event type |
|
* |
|
* Clients should not be concerned about wake line behavior. However, due |
|
* to a race condition in HSI HW protocol, clients need to be notified |
|
* about wake line changes, so they can implement a workaround for it. |
|
* |
|
* Events: |
|
* HSI_EVENT_START_RX - Incoming wake line high |
|
* HSI_EVENT_STOP_RX - Incoming wake line down |
|
* |
|
* Returns -errno on error, or 0 on success. |
|
*/ |
|
int hsi_event(struct hsi_port *port, unsigned long event) |
|
{ |
|
return blocking_notifier_call_chain(&port->n_head, event, NULL); |
|
} |
|
EXPORT_SYMBOL_GPL(hsi_event); |
|
|
|
/** |
|
* hsi_get_channel_id_by_name - acquire channel id by channel name |
|
* @cl: HSI client, which uses the channel |
|
* @name: name the channel is known under |
|
* |
|
* Clients can call this function to get the hsi channel ids similar to |
|
* requesting IRQs or GPIOs by name. This function assumes the same |
|
* channel configuration is used for RX and TX. |
|
* |
|
* Returns -errno on error or channel id on success. |
|
*/ |
|
int hsi_get_channel_id_by_name(struct hsi_client *cl, char *name) |
|
{ |
|
int i; |
|
|
|
if (!cl->rx_cfg.channels) |
|
return -ENOENT; |
|
|
|
for (i = 0; i < cl->rx_cfg.num_channels; i++) |
|
if (!strcmp(cl->rx_cfg.channels[i].name, name)) |
|
return cl->rx_cfg.channels[i].id; |
|
|
|
return -ENXIO; |
|
} |
|
EXPORT_SYMBOL_GPL(hsi_get_channel_id_by_name); |
|
|
|
static int __init hsi_init(void) |
|
{ |
|
return bus_register(&hsi_bus_type); |
|
} |
|
postcore_initcall(hsi_init); |
|
|
|
static void __exit hsi_exit(void) |
|
{ |
|
bus_unregister(&hsi_bus_type); |
|
} |
|
module_exit(hsi_exit); |
|
|
|
MODULE_AUTHOR("Carlos Chinea <[email protected]>"); |
|
MODULE_DESCRIPTION("High-speed Synchronous Serial Interface (HSI) framework"); |
|
MODULE_LICENSE("GPL v2");
|
|
|