/* * drivers/mfd/si476x-i2c.c -- Core device driver for si476x MFD * device * * Copyright (C) 2012 Innovative Converged Devices(ICD) * Copyright (C) 2013 Andrey Smirnov * * Author: Andrey Smirnov <andrew.smirnov@gmail.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * */ #include <linux/module.h> #include <linux/slab.h> #include <linux/interrupt.h> #include <linux/delay.h> #include <linux/gpio.h> #include <linux/regulator/consumer.h> #include <linux/i2c.h> #include <linux/err.h> #include <linux/mfd/si476x-core.h> #define SI476X_MAX_IO_ERRORS 10 #define SI476X_DRIVER_RDS_FIFO_DEPTH 128 /** * si476x_core_config_pinmux() - pin function configuration function * * @core: Core device structure * * Configure the functions of the pins of the radio chip. * * The function returns zero in case of succes or negative error code * otherwise. */ static int si476x_core_config_pinmux(struct si476x_core *core) { int err; dev_dbg(&core->client->dev, "Configuring pinmux\n"); err = si476x_core_cmd_dig_audio_pin_cfg(core, core->pinmux.dclk, core->pinmux.dfs, core->pinmux.dout, core->pinmux.xout); if (err < 0) { dev_err(&core->client->dev, "Failed to configure digital audio pins(err = %d)\n", err); return err; } err = si476x_core_cmd_zif_pin_cfg(core, core->pinmux.iqclk, core->pinmux.iqfs, core->pinmux.iout, core->pinmux.qout); if (err < 0) { dev_err(&core->client->dev, "Failed to configure ZIF pins(err = %d)\n", err); return err; } err = si476x_core_cmd_ic_link_gpo_ctl_pin_cfg(core, core->pinmux.icin, core->pinmux.icip, core->pinmux.icon, core->pinmux.icop); if (err < 0) { dev_err(&core->client->dev, "Failed to configure IC-Link/GPO pins(err = %d)\n", err); return err; } err = si476x_core_cmd_ana_audio_pin_cfg(core, core->pinmux.lrout); if (err < 0) { dev_err(&core->client->dev, "Failed to configure analog audio pins(err = %d)\n", err); return err; } err = si476x_core_cmd_intb_pin_cfg(core, core->pinmux.intb, core->pinmux.a1); if (err < 0) { dev_err(&core->client->dev, "Failed to configure interrupt pins(err = %d)\n", err); return err; } return 0; } static inline void si476x_core_schedule_polling_work(struct si476x_core *core) { schedule_delayed_work(&core->status_monitor, usecs_to_jiffies(SI476X_STATUS_POLL_US)); } /** * si476x_core_start() - early chip startup function * @core: Core device structure * @soft: When set, this flag forces "soft" startup, where "soft" * power down is the one done by sending appropriate command instead * of using reset pin of the tuner * * Perform required startup sequence to correctly power * up the chip and perform initial configuration. It does the * following sequence of actions: * 1. Claims and enables the power supplies VD and VIO1 required * for I2C interface of the chip operation. * 2. Waits for 100us, pulls the reset line up, enables irq, * waits for another 100us as it is specified by the * datasheet. * 3. Sends 'POWER_UP' command to the device with all provided * information about power-up parameters. * 4. Configures, pin multiplexor, disables digital audio and * configures interrupt sources. * * The function returns zero in case of succes or negative error code * otherwise. */ int si476x_core_start(struct si476x_core *core, bool soft) { struct i2c_client *client = core->client; int err; if (!soft) { if (gpio_is_valid(core->gpio_reset)) gpio_set_value_cansleep(core->gpio_reset, 1); if (client->irq) enable_irq(client->irq); udelay(100); if (!client->irq) { atomic_set(&core->is_alive, 1); si476x_core_schedule_polling_work(core); } } else { if (client->irq) enable_irq(client->irq); else { atomic_set(&core->is_alive, 1); si476x_core_schedule_polling_work(core); } } err = si476x_core_cmd_power_up(core, &core->power_up_parameters); if (err < 0) { dev_err(&core->client->dev, "Power up failure(err = %d)\n", err); goto disable_irq; } if (client->irq) atomic_set(&core->is_alive, 1); err = si476x_core_config_pinmux(core); if (err < 0) { dev_err(&core->client->dev, "Failed to configure pinmux(err = %d)\n", err); goto disable_irq; } if (client->irq) { err = regmap_write(core->regmap, SI476X_PROP_INT_CTL_ENABLE, SI476X_RDSIEN | SI476X_STCIEN | SI476X_CTSIEN); if (err < 0) { dev_err(&core->client->dev, "Failed to configure interrupt sources" "(err = %d)\n", err); goto disable_irq; } } return 0; disable_irq: if (err == -ENODEV) atomic_set(&core->is_alive, 0); if (client->irq) disable_irq(client->irq); else cancel_delayed_work_sync(&core->status_monitor); if (gpio_is_valid(core->gpio_reset)) gpio_set_value_cansleep(core->gpio_reset, 0); return err; } EXPORT_SYMBOL_GPL(si476x_core_start); /** * si476x_core_stop() - chip power-down function * @core: Core device structure * @soft: When set, function sends a POWER_DOWN command instead of * bringing reset line low * * Power down the chip by performing following actions: * 1. Disable IRQ or stop the polling worker * 2. Send the POWER_DOWN command if the power down is soft or bring * reset line low if not. * * The function returns zero in case of succes or negative error code * otherwise. */ int si476x_core_stop(struct si476x_core *core, bool soft) { int err = 0; atomic_set(&core->is_alive, 0); if (soft) { /* TODO: This probably shoud be a configurable option, * so it is possible to have the chips keep their * oscillators running */ struct si476x_power_down_args args = { .xosc = false, }; err = si476x_core_cmd_power_down(core, &args); } /* We couldn't disable those before * 'si476x_core_cmd_power_down' since we expect to get CTS * interrupt */ if (core->client->irq) disable_irq(core->client->irq); else cancel_delayed_work_sync(&core->status_monitor); if (!soft) { if (gpio_is_valid(core->gpio_reset)) gpio_set_value_cansleep(core->gpio_reset, 0); } return err; } EXPORT_SYMBOL_GPL(si476x_core_stop); /** * si476x_core_set_power_state() - set the level at which the power is * supplied for the chip. * @core: Core device structure * @next_state: enum si476x_power_state describing power state to * switch to. * * Switch on all the required power supplies * * This function returns 0 in case of suvccess and negative error code * otherwise. */ int si476x_core_set_power_state(struct si476x_core *core, enum si476x_power_state next_state) { /* It is not clear form the datasheet if it is possible to work with device if not all power domains are operational. So for now the power-up policy is "power-up all the things!" */ int err = 0; if (core->power_state == SI476X_POWER_INCONSISTENT) { dev_err(&core->client->dev, "The device in inconsistent power state\n"); return -EINVAL; } if (next_state != core->power_state) { switch (next_state) { case SI476X_POWER_UP_FULL: err = regulator_bulk_enable(ARRAY_SIZE(core->supplies), core->supplies); if (err < 0) { core->power_state = SI476X_POWER_INCONSISTENT; break; } /* * Startup timing diagram recommends to have a * 100 us delay between enabling of the power * supplies and turning the tuner on. */ udelay(100); err = si476x_core_start(core, false); if (err < 0) goto disable_regulators; core->power_state = next_state; break; case SI476X_POWER_DOWN: core->power_state = next_state; err = si476x_core_stop(core, false); if (err < 0) core->power_state = SI476X_POWER_INCONSISTENT; disable_regulators: err = regulator_bulk_disable(ARRAY_SIZE(core->supplies), core->supplies); if (err < 0) core->power_state = SI476X_POWER_INCONSISTENT; break; default: BUG(); } } return err; } EXPORT_SYMBOL_GPL(si476x_core_set_power_state); /** * si476x_core_report_drainer_stop() - mark the completion of the RDS * buffer drain porcess by the worker. * * @core: Core device structure */ static inline void si476x_core_report_drainer_stop(struct si476x_core *core) { mutex_lock(&core->rds_drainer_status_lock); core->rds_drainer_is_working = false; mutex_unlock(&core->rds_drainer_status_lock); } /** * si476x_core_start_rds_drainer_once() - start RDS drainer worker if * ther is none working, do nothing otherwise * * @core: Datastructure corresponding to the chip. */ static inline void si476x_core_start_rds_drainer_once(struct si476x_core *core) { mutex_lock(&core->rds_drainer_status_lock); if (!core->rds_drainer_is_working) { core->rds_drainer_is_working = true; schedule_work(&core->rds_fifo_drainer); } mutex_unlock(&core->rds_drainer_status_lock); } /** * si476x_drain_rds_fifo() - RDS buffer drainer. * @work: struct work_struct being ppassed to the function by the * kernel. * * Drain the contents of the RDS FIFO of */ static void si476x_core_drain_rds_fifo(struct work_struct *work) { int err; struct si476x_core *core = container_of(work, struct si476x_core, rds_fifo_drainer); struct si476x_rds_status_report report; si476x_core_lock(core); err = si476x_core_cmd_fm_rds_status(core, true, false, false, &report); if (!err) { int i = report.rdsfifoused; dev_dbg(&core->client->dev, "%d elements in RDS FIFO. Draining.\n", i); for (; i > 0; --i) { err = si476x_core_cmd_fm_rds_status(core, false, false, (i == 1), &report); if (err < 0) goto unlock; kfifo_in(&core->rds_fifo, report.rds, sizeof(report.rds)); dev_dbg(&core->client->dev, "RDS data:\n %*ph\n", (int)sizeof(report.rds), report.rds); } dev_dbg(&core->client->dev, "Drrrrained!\n"); wake_up_interruptible(&core->rds_read_queue); } unlock: si476x_core_unlock(core); si476x_core_report_drainer_stop(core); } /** * si476x_core_pronounce_dead() * * @core: Core device structure * * Mark the device as being dead and wake up all potentially waiting * threads of execution. * */ static void si476x_core_pronounce_dead(struct si476x_core *core) { dev_info(&core->client->dev, "Core device is dead.\n"); atomic_set(&core->is_alive, 0); /* Wake up al possible waiting processes */ wake_up_interruptible(&core->rds_read_queue); atomic_set(&core->cts, 1); wake_up(&core->command); atomic_set(&core->stc, 1); wake_up(&core->tuning); } /** * si476x_core_i2c_xfer() * * @core: Core device structure * @type: Transfer type * @buf: Transfer buffer for/with data * @count: Transfer buffer size * * Perfrom and I2C transfer(either read or write) and keep a counter * of I/O errors. If the error counter rises above the threshold * pronounce device dead. * * The function returns zero on succes or negative error code on * failure. */ int si476x_core_i2c_xfer(struct si476x_core *core, enum si476x_i2c_type type, char *buf, int count) { static int io_errors_count; int err; if (type == SI476X_I2C_SEND) err = i2c_master_send(core->client, buf, count); else err = i2c_master_recv(core->client, buf, count); if (err < 0) { if (io_errors_count++ > SI476X_MAX_IO_ERRORS) si476x_core_pronounce_dead(core); } else { io_errors_count = 0; } return err; } EXPORT_SYMBOL_GPL(si476x_core_i2c_xfer); /** * si476x_get_status() * @core: Core device structure * * Get the status byte of the core device by berforming one byte I2C * read. * * The function returns a status value or a negative error code on * error. */ static int si476x_core_get_status(struct si476x_core *core) { u8 response; int err = si476x_core_i2c_xfer(core, SI476X_I2C_RECV, &response, sizeof(response)); return (err < 0) ? err : response; } /** * si476x_get_and_signal_status() - IRQ dispatcher * @core: Core device structure * * Dispatch the arrived interrupt request based on the value of the * status byte reported by the tuner. * */ static void si476x_core_get_and_signal_status(struct si476x_core *core) { int status = si476x_core_get_status(core); if (status < 0) { dev_err(&core->client->dev, "Failed to get status\n"); return; } if (status & SI476X_CTS) { /* Unfortunately completions could not be used for * signalling CTS since this flag cannot be cleared * in status byte, and therefore once it becomes true * multiple calls to 'complete' would cause the * commands following the current one to be completed * before they actually are */ dev_dbg(&core->client->dev, "[interrupt] CTSINT\n"); atomic_set(&core->cts, 1); wake_up(&core->command); } if (status & SI476X_FM_RDS_INT) { dev_dbg(&core->client->dev, "[interrupt] RDSINT\n"); si476x_core_start_rds_drainer_once(core); } if (status & SI476X_STC_INT) { dev_dbg(&core->client->dev, "[interrupt] STCINT\n"); atomic_set(&core->stc, 1); wake_up(&core->tuning); } } static void si476x_core_poll_loop(struct work_struct *work) { struct si476x_core *core = SI476X_WORK_TO_CORE(work); si476x_core_get_and_signal_status(core); if (atomic_read(&core->is_alive)) si476x_core_schedule_polling_work(core); } static irqreturn_t si476x_core_interrupt(int irq, void *dev) { struct si476x_core *core = dev; si476x_core_get_and_signal_status(core); return IRQ_HANDLED; } /** * si476x_firmware_version_to_revision() * @core: Core device structure * @major: Firmware major number * @minor1: Firmware first minor number * @minor2: Firmware second minor number * * Convert a chip's firmware version number into an offset that later * will be used to as offset in "vtable" of tuner functions * * This function returns a positive offset in case of success and a -1 * in case of failure. */ static int si476x_core_fwver_to_revision(struct si476x_core *core, int func, int major, int minor1, int minor2) { switch (func) { case SI476X_FUNC_FM_RECEIVER: switch (major) { case 5: return SI476X_REVISION_A10; case 8: return SI476X_REVISION_A20; case 10: return SI476X_REVISION_A30; default: goto unknown_revision; } case SI476X_FUNC_AM_RECEIVER: switch (major) { case 5: return SI476X_REVISION_A10; case 7: return SI476X_REVISION_A20; case 9: return SI476X_REVISION_A30; default: goto unknown_revision; } case SI476X_FUNC_WB_RECEIVER: switch (major) { case 3: return SI476X_REVISION_A10; case 5: return SI476X_REVISION_A20; case 7: return SI476X_REVISION_A30; default: goto unknown_revision; } case SI476X_FUNC_BOOTLOADER: default: /* FALLTHROUG */ BUG(); return -1; } unknown_revision: dev_err(&core->client->dev, "Unsupported version of the firmware: %d.%d.%d, " "reverting to A10 compatible functions\n", major, minor1, minor2); return SI476X_REVISION_A10; } /** * si476x_get_revision_info() * @core: Core device structure * * Get the firmware version number of the device. It is done in * following three steps: * 1. Power-up the device * 2. Send the 'FUNC_INFO' command * 3. Powering the device down. * * The function return zero on success and a negative error code on * failure. */ static int si476x_core_get_revision_info(struct si476x_core *core) { int rval; struct si476x_func_info info; si476x_core_lock(core); rval = si476x_core_set_power_state(core, SI476X_POWER_UP_FULL); if (rval < 0) goto exit; rval = si476x_core_cmd_func_info(core, &info); if (rval < 0) goto power_down; core->revision = si476x_core_fwver_to_revision(core, info.func, info.firmware.major, info.firmware.minor[0], info.firmware.minor[1]); power_down: si476x_core_set_power_state(core, SI476X_POWER_DOWN); exit: si476x_core_unlock(core); return rval; } bool si476x_core_has_am(struct si476x_core *core) { return core->chip_id == SI476X_CHIP_SI4761 || core->chip_id == SI476X_CHIP_SI4764; } EXPORT_SYMBOL_GPL(si476x_core_has_am); bool si476x_core_has_diversity(struct si476x_core *core) { return core->chip_id == SI476X_CHIP_SI4764; } EXPORT_SYMBOL_GPL(si476x_core_has_diversity); bool si476x_core_is_a_secondary_tuner(struct si476x_core *core) { return si476x_core_has_diversity(core) && (core->diversity_mode == SI476X_PHDIV_SECONDARY_ANTENNA || core->diversity_mode == SI476X_PHDIV_SECONDARY_COMBINING); } EXPORT_SYMBOL_GPL(si476x_core_is_a_secondary_tuner); bool si476x_core_is_a_primary_tuner(struct si476x_core *core) { return si476x_core_has_diversity(core) && (core->diversity_mode == SI476X_PHDIV_PRIMARY_ANTENNA || core->diversity_mode == SI476X_PHDIV_PRIMARY_COMBINING); } EXPORT_SYMBOL_GPL(si476x_core_is_a_primary_tuner); bool si476x_core_is_in_am_receiver_mode(struct si476x_core *core) { return si476x_core_has_am(core) && (core->power_up_parameters.func == SI476X_FUNC_AM_RECEIVER); } EXPORT_SYMBOL_GPL(si476x_core_is_in_am_receiver_mode); bool si476x_core_is_powered_up(struct si476x_core *core) { return core->power_state == SI476X_POWER_UP_FULL; } EXPORT_SYMBOL_GPL(si476x_core_is_powered_up); static int si476x_core_probe(struct i2c_client *client, const struct i2c_device_id *id) { int rval; struct si476x_core *core; struct si476x_platform_data *pdata; struct mfd_cell *cell; int cell_num; core = devm_kzalloc(&client->dev, sizeof(*core), GFP_KERNEL); if (!core) { dev_err(&client->dev, "failed to allocate 'struct si476x_core'\n"); return -ENOMEM; } core->client = client; core->regmap = devm_regmap_init_si476x(core); if (IS_ERR(core->regmap)) { rval = PTR_ERR(core->regmap); dev_err(&client->dev, "Failed to allocate register map: %d\n", rval); return rval; } i2c_set_clientdata(client, core); atomic_set(&core->is_alive, 0); core->power_state = SI476X_POWER_DOWN; pdata = dev_get_platdata(&client->dev); if (pdata) { memcpy(&core->power_up_parameters, &pdata->power_up_parameters, sizeof(core->power_up_parameters)); core->gpio_reset = -1; if (gpio_is_valid(pdata->gpio_reset)) { rval = gpio_request(pdata->gpio_reset, "si476x reset"); if (rval) { dev_err(&client->dev, "Failed to request gpio: %d\n", rval); return rval; } core->gpio_reset = pdata->gpio_reset; gpio_direction_output(core->gpio_reset, 0); } core->diversity_mode = pdata->diversity_mode; memcpy(&core->pinmux, &pdata->pinmux, sizeof(struct si476x_pinmux)); } else { dev_err(&client->dev, "No platform data provided\n"); return -EINVAL; } core->supplies[0].supply = "vd"; core->supplies[1].supply = "va"; core->supplies[2].supply = "vio1"; core->supplies[3].supply = "vio2"; rval = devm_regulator_bulk_get(&client->dev, ARRAY_SIZE(core->supplies), core->supplies); if (rval) { dev_err(&client->dev, "Failed to get all of the regulators\n"); goto free_gpio; } mutex_init(&core->cmd_lock); init_waitqueue_head(&core->command); init_waitqueue_head(&core->tuning); rval = kfifo_alloc(&core->rds_fifo, SI476X_DRIVER_RDS_FIFO_DEPTH * sizeof(struct v4l2_rds_data), GFP_KERNEL); if (rval) { dev_err(&client->dev, "Could not allocate the FIFO\n"); goto free_gpio; } mutex_init(&core->rds_drainer_status_lock); init_waitqueue_head(&core->rds_read_queue); INIT_WORK(&core->rds_fifo_drainer, si476x_core_drain_rds_fifo); if (client->irq) { rval = devm_request_threaded_irq(&client->dev, client->irq, NULL, si476x_core_interrupt, IRQF_TRIGGER_FALLING | IRQF_ONESHOT, client->name, core); if (rval < 0) { dev_err(&client->dev, "Could not request IRQ %d\n", client->irq); goto free_kfifo; } disable_irq(client->irq); dev_dbg(&client->dev, "IRQ requested.\n"); core->rds_fifo_depth = 20; } else { INIT_DELAYED_WORK(&core->status_monitor, si476x_core_poll_loop); dev_info(&client->dev, "No IRQ number specified, will use polling\n"); core->rds_fifo_depth = 5; } core->chip_id = id->driver_data; rval = si476x_core_get_revision_info(core); if (rval < 0) { rval = -ENODEV; goto free_kfifo; } cell_num = 0; cell = &core->cells[SI476X_RADIO_CELL]; cell->name = "si476x-radio"; cell_num++; #ifdef CONFIG_SND_SOC_SI476X if ((core->chip_id == SI476X_CHIP_SI4761 || core->chip_id == SI476X_CHIP_SI4764) && core->pinmux.dclk == SI476X_DCLK_DAUDIO && core->pinmux.dfs == SI476X_DFS_DAUDIO && core->pinmux.dout == SI476X_DOUT_I2S_OUTPUT && core->pinmux.xout == SI476X_XOUT_TRISTATE) { cell = &core->cells[SI476X_CODEC_CELL]; cell->name = "si476x-codec"; cell_num++; } #endif rval = mfd_add_devices(&client->dev, (client->adapter->nr << 8) + client->addr, core->cells, cell_num, NULL, 0, NULL); if (!rval) return 0; free_kfifo: kfifo_free(&core->rds_fifo); free_gpio: if (gpio_is_valid(core->gpio_reset)) gpio_free(core->gpio_reset); return rval; } static int si476x_core_remove(struct i2c_client *client) { struct si476x_core *core = i2c_get_clientdata(client); si476x_core_pronounce_dead(core); mfd_remove_devices(&client->dev); if (client->irq) disable_irq(client->irq); else cancel_delayed_work_sync(&core->status_monitor); kfifo_free(&core->rds_fifo); if (gpio_is_valid(core->gpio_reset)) gpio_free(core->gpio_reset); return 0; } static const struct i2c_device_id si476x_id[] = { { "si4761", SI476X_CHIP_SI4761 }, { "si4764", SI476X_CHIP_SI4764 }, { "si4768", SI476X_CHIP_SI4768 }, { }, }; MODULE_DEVICE_TABLE(i2c, si476x_id); static struct i2c_driver si476x_core_driver = { .driver = { .name = "si476x-core", }, .probe = si476x_core_probe, .remove = si476x_core_remove, .id_table = si476x_id, }; module_i2c_driver(si476x_core_driver); MODULE_AUTHOR("Andrey Smirnov <andrew.smirnov@gmail.com>"); MODULE_DESCRIPTION("Si4761/64/68 AM/FM MFD core device driver"); MODULE_LICENSE("GPL");