Author | Tokens | Token Proportion | Commits | Commit Proportion |
---|---|---|---|---|
Christian Gromm | 1428 | 98.01% | 15 | 71.43% |
Menna Mahmoud | 21 | 1.44% | 1 | 4.76% |
Lee Jones | 3 | 0.21% | 1 | 4.76% |
Shraddha Barke | 2 | 0.14% | 1 | 4.76% |
Uwe Kleine-König | 2 | 0.14% | 2 | 9.52% |
Greg Kroah-Hartman | 1 | 0.07% | 1 | 4.76% |
Total | 1457 | 21 |
// SPDX-License-Identifier: GPL-2.0 /* * i2c.c - Hardware Dependent Module for I2C Interface * * Copyright (C) 2013-2015, Microchip Technology Germany II GmbH & Co. KG */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/init.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/i2c.h> #include <linux/interrupt.h> #include <linux/err.h> #include <linux/most.h> enum { CH_RX, CH_TX, NUM_CHANNELS }; #define MAX_BUFFERS_CONTROL 32 #define MAX_BUF_SIZE_CONTROL 256 /** * list_first_mbo - get the first mbo from a list * @ptr: the list head to take the mbo from. */ #define list_first_mbo(ptr) \ list_first_entry(ptr, struct mbo, list) static unsigned int polling_rate; module_param(polling_rate, uint, 0644); MODULE_PARM_DESC(polling_rate, "Polling rate [Hz]. Default = 0 (use IRQ)"); struct hdm_i2c { struct most_interface most_iface; struct most_channel_capability capabilities[NUM_CHANNELS]; struct i2c_client *client; struct rx { struct delayed_work dwork; struct list_head list; bool int_disabled; unsigned int delay; } rx; char name[64]; }; static inline struct hdm_i2c *to_hdm(struct most_interface *iface) { return container_of(iface, struct hdm_i2c, most_iface); } static irqreturn_t most_irq_handler(int, void *); static void pending_rx_work(struct work_struct *); /** * configure_channel - called from MOST core to configure a channel * @most_iface: interface the channel belongs to * @ch_idx: channel to be configured * @channel_config: structure that holds the configuration information * * Return 0 on success, negative on failure. * * Receives configuration information from MOST core and initialize the * corresponding channel. */ static int configure_channel(struct most_interface *most_iface, int ch_idx, struct most_channel_config *channel_config) { int ret; struct hdm_i2c *dev = to_hdm(most_iface); unsigned int delay, pr; BUG_ON(ch_idx < 0 || ch_idx >= NUM_CHANNELS); if (channel_config->data_type != MOST_CH_CONTROL) { pr_err("bad data type for channel %d\n", ch_idx); return -EPERM; } if (channel_config->direction != dev->capabilities[ch_idx].direction) { pr_err("bad direction for channel %d\n", ch_idx); return -EPERM; } if (channel_config->direction == MOST_CH_RX) { if (!polling_rate) { if (dev->client->irq <= 0) { pr_err("bad irq: %d\n", dev->client->irq); return -ENOENT; } dev->rx.int_disabled = false; ret = request_irq(dev->client->irq, most_irq_handler, 0, dev->client->name, dev); if (ret) { pr_err("request_irq(%d) failed: %d\n", dev->client->irq, ret); return ret; } } else { delay = msecs_to_jiffies(MSEC_PER_SEC / polling_rate); dev->rx.delay = delay ? delay : 1; pr = MSEC_PER_SEC / jiffies_to_msecs(dev->rx.delay); pr_info("polling rate is %u Hz\n", pr); } } return 0; } /** * enqueue - called from MOST core to enqueue a buffer for data transfer * @most_iface: intended interface * @ch_idx: ID of the channel the buffer is intended for * @mbo: pointer to the buffer object * * Return 0 on success, negative on failure. * * Transmit the data over I2C if it is a "write" request or push the buffer into * list if it is an "read" request */ static int enqueue(struct most_interface *most_iface, int ch_idx, struct mbo *mbo) { struct hdm_i2c *dev = to_hdm(most_iface); int ret; BUG_ON(ch_idx < 0 || ch_idx >= NUM_CHANNELS); if (ch_idx == CH_RX) { /* RX */ if (!polling_rate) disable_irq(dev->client->irq); cancel_delayed_work_sync(&dev->rx.dwork); list_add_tail(&mbo->list, &dev->rx.list); if (dev->rx.int_disabled || polling_rate) pending_rx_work(&dev->rx.dwork.work); if (!polling_rate) enable_irq(dev->client->irq); } else { /* TX */ ret = i2c_master_send(dev->client, mbo->virt_address, mbo->buffer_length); if (ret <= 0) { mbo->processed_length = 0; mbo->status = MBO_E_INVAL; } else { mbo->processed_length = mbo->buffer_length; mbo->status = MBO_SUCCESS; } mbo->complete(mbo); } return 0; } /** * poison_channel - called from MOST core to poison buffers of a channel * @most_iface: pointer to the interface the channel to be poisoned belongs to * @ch_idx: corresponding channel ID * * Return 0 on success, negative on failure. * * If channel direction is RX, complete the buffers in list with * status MBO_E_CLOSE */ static int poison_channel(struct most_interface *most_iface, int ch_idx) { struct hdm_i2c *dev = to_hdm(most_iface); struct mbo *mbo; BUG_ON(ch_idx < 0 || ch_idx >= NUM_CHANNELS); if (ch_idx == CH_RX) { if (!polling_rate) free_irq(dev->client->irq, dev); cancel_delayed_work_sync(&dev->rx.dwork); while (!list_empty(&dev->rx.list)) { mbo = list_first_mbo(&dev->rx.list); list_del(&mbo->list); mbo->processed_length = 0; mbo->status = MBO_E_CLOSE; mbo->complete(mbo); } } return 0; } static void do_rx_work(struct hdm_i2c *dev) { struct mbo *mbo; unsigned char msg[MAX_BUF_SIZE_CONTROL]; int ret; u16 pml, data_size; /* Read PML (2 bytes) */ ret = i2c_master_recv(dev->client, msg, 2); if (ret <= 0) { pr_err("Failed to receive PML\n"); return; } pml = (msg[0] << 8) | msg[1]; if (!pml) return; data_size = pml + 2; /* Read the whole message, including PML */ ret = i2c_master_recv(dev->client, msg, data_size); if (ret <= 0) { pr_err("Failed to receive a Port Message\n"); return; } mbo = list_first_mbo(&dev->rx.list); list_del(&mbo->list); mbo->processed_length = min(data_size, mbo->buffer_length); memcpy(mbo->virt_address, msg, mbo->processed_length); mbo->status = MBO_SUCCESS; mbo->complete(mbo); } /** * pending_rx_work - Read pending messages through I2C * @work: definition of this work item * * Invoked by the Interrupt Service Routine, most_irq_handler() */ static void pending_rx_work(struct work_struct *work) { struct hdm_i2c *dev = container_of(work, struct hdm_i2c, rx.dwork.work); if (list_empty(&dev->rx.list)) return; do_rx_work(dev); if (polling_rate) { schedule_delayed_work(&dev->rx.dwork, dev->rx.delay); } else { dev->rx.int_disabled = false; enable_irq(dev->client->irq); } } /* * most_irq_handler - Interrupt Service Routine * @irq: irq number * @_dev: private data * * Schedules a delayed work * * By default the interrupt line behavior is Active Low. Once an interrupt is * generated by the device, until driver clears the interrupt (by reading * the PMP message), device keeps the interrupt line in low state. Since i2c * read is done in work queue, the interrupt line must be disabled temporarily * to avoid ISR being called repeatedly. Re-enable the interrupt in workqueue, * after reading the message. * * Note: If we use the interrupt line in Falling edge mode, there is a * possibility to miss interrupts when ISR is getting executed. * */ static irqreturn_t most_irq_handler(int irq, void *_dev) { struct hdm_i2c *dev = _dev; disable_irq_nosync(irq); dev->rx.int_disabled = true; schedule_delayed_work(&dev->rx.dwork, 0); return IRQ_HANDLED; } /* * i2c_probe - i2c probe handler * @client: i2c client device structure * @id: i2c client device id * * Return 0 on success, negative on failure. * * Register the i2c client device as a MOST interface */ static int i2c_probe(struct i2c_client *client) { struct hdm_i2c *dev; int ret, i; dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (!dev) return -ENOMEM; /* ID format: i2c-<bus>-<address> */ snprintf(dev->name, sizeof(dev->name), "i2c-%d-%04x", client->adapter->nr, client->addr); for (i = 0; i < NUM_CHANNELS; i++) { dev->capabilities[i].data_type = MOST_CH_CONTROL; dev->capabilities[i].num_buffers_packet = MAX_BUFFERS_CONTROL; dev->capabilities[i].buffer_size_packet = MAX_BUF_SIZE_CONTROL; } dev->capabilities[CH_RX].direction = MOST_CH_RX; dev->capabilities[CH_RX].name_suffix = "rx"; dev->capabilities[CH_TX].direction = MOST_CH_TX; dev->capabilities[CH_TX].name_suffix = "tx"; dev->most_iface.interface = ITYPE_I2C; dev->most_iface.description = dev->name; dev->most_iface.num_channels = NUM_CHANNELS; dev->most_iface.channel_vector = dev->capabilities; dev->most_iface.configure = configure_channel; dev->most_iface.enqueue = enqueue; dev->most_iface.poison_channel = poison_channel; INIT_LIST_HEAD(&dev->rx.list); INIT_DELAYED_WORK(&dev->rx.dwork, pending_rx_work); dev->client = client; i2c_set_clientdata(client, dev); ret = most_register_interface(&dev->most_iface); if (ret) { pr_err("Failed to register i2c as a MOST interface\n"); kfree(dev); return ret; } return 0; } /* * i2c_remove - i2c remove handler * @client: i2c client device structure * * Return 0 on success. * * Unregister the i2c client device as a MOST interface */ static void i2c_remove(struct i2c_client *client) { struct hdm_i2c *dev = i2c_get_clientdata(client); most_deregister_interface(&dev->most_iface); kfree(dev); } static const struct i2c_device_id i2c_id[] = { { "most_i2c", 0 }, { }, /* Terminating entry */ }; MODULE_DEVICE_TABLE(i2c, i2c_id); static struct i2c_driver i2c_driver = { .driver = { .name = "hdm_i2c", }, .probe = i2c_probe, .remove = i2c_remove, .id_table = i2c_id, }; module_i2c_driver(i2c_driver); MODULE_AUTHOR("Andrey Shvetsov <andrey.shvetsov@k2l.de>"); MODULE_DESCRIPTION("I2C Hardware Dependent Module"); MODULE_LICENSE("GPL");
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with Cregit http://github.com/cregit/cregit
Version 2.0-RC1