| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Romain Gantois | 1813 | 99.89% | 1 | 50.00% |
| Cosmin Tanislav | 2 | 0.11% | 1 | 50.00% |
| Total | 1815 | 2 |
// SPDX-License-Identifier: GPL-2.0-only /* * ti_fpc202.c - FPC202 Dual Port Controller driver * * Copyright (C) 2024 Bootlin * */ #include <linux/cleanup.h> #include <linux/err.h> #include <linux/i2c.h> #include <linux/i2c-atr.h> #include <linux/gpio/consumer.h> #include <linux/gpio/driver.h> #include <linux/module.h> #define FPC202_NUM_PORTS 2 #define FPC202_ALIASES_PER_PORT 2 /* * GPIO: port mapping * * 0: P0_S0_IN_A * 1: P0_S1_IN_A * 2: P1_S0_IN_A * 3: P1_S1_IN_A * 4: P0_S0_IN_B * ... * 8: P0_S0_IN_C * ... * 12: P0_S0_OUT_A * ... * 16: P0_S0_OUT_B * ... * 19: P1_S1_OUT_B * */ #define FPC202_GPIO_COUNT 20 #define FPC202_GPIO_P0_S0_IN_B 4 #define FPC202_GPIO_P0_S0_OUT_A 12 #define FPC202_REG_IN_A_INT 0x6 #define FPC202_REG_IN_C_IN_B 0x7 #define FPC202_REG_OUT_A_OUT_B 0x8 #define FPC202_REG_OUT_A_OUT_B_VAL 0xa #define FPC202_REG_MOD_DEV(port, dev) (0xb4 + ((port) * 4) + (dev)) #define FPC202_REG_AUX_DEV(port, dev) (0xb6 + ((port) * 4) + (dev)) /* * The FPC202 doesn't support turning off address translation on a single port. * So just set an invalid I2C address as the translation target when no client * address is attached. */ #define FPC202_REG_DEV_INVALID 0 /* Even aliases are assigned to device 0 and odd aliases to device 1 */ #define fpc202_dev_num_from_alias(alias) ((alias) % 2) struct fpc202_priv { struct i2c_client *client; struct i2c_atr *atr; struct gpio_desc *en_gpio; struct gpio_chip gpio; /* Lock REG_MOD/AUX_DEV and addr_caches during attach/detach */ struct mutex reg_dev_lock; /* Cached device addresses for both ports and their devices */ u8 addr_caches[2][2]; /* Keep track of which ports were probed */ DECLARE_BITMAP(probed_ports, FPC202_NUM_PORTS); }; static void fpc202_fill_alias_table(struct i2c_client *client, u16 *aliases, int port_id) { u16 first_alias; int i; /* * There is a predefined list of aliases for each FPC202 I2C * self-address. This allows daisy-chained FPC202 units to * automatically take on different sets of aliases. * Each port of an FPC202 unit is assigned two aliases from this list. */ first_alias = 0x10 + 4 * port_id + 8 * ((u16)client->addr - 2); for (i = 0; i < FPC202_ALIASES_PER_PORT; i++) aliases[i] = first_alias + i; } static int fpc202_gpio_get_dir(int offset) { return offset < FPC202_GPIO_P0_S0_OUT_A ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT; } static int fpc202_read(struct fpc202_priv *priv, u8 reg) { int val; val = i2c_smbus_read_byte_data(priv->client, reg); return val; } static int fpc202_write(struct fpc202_priv *priv, u8 reg, u8 value) { return i2c_smbus_write_byte_data(priv->client, reg, value); } static void fpc202_set_enable(struct fpc202_priv *priv, int enable) { if (!priv->en_gpio) return; gpiod_set_value(priv->en_gpio, enable); } static void fpc202_gpio_set(struct gpio_chip *chip, unsigned int offset, int value) { struct fpc202_priv *priv = gpiochip_get_data(chip); int ret; u8 val; if (fpc202_gpio_get_dir(offset) == GPIO_LINE_DIRECTION_IN) return; ret = fpc202_read(priv, FPC202_REG_OUT_A_OUT_B_VAL); if (ret < 0) { dev_err(&priv->client->dev, "Failed to set GPIO %d value! err %d\n", offset, ret); return; } val = (u8)ret; if (value) val |= BIT(offset - FPC202_GPIO_P0_S0_OUT_A); else val &= ~BIT(offset - FPC202_GPIO_P0_S0_OUT_A); fpc202_write(priv, FPC202_REG_OUT_A_OUT_B_VAL, val); } static int fpc202_gpio_get(struct gpio_chip *chip, unsigned int offset) { struct fpc202_priv *priv = gpiochip_get_data(chip); u8 reg, bit; int ret; if (offset < FPC202_GPIO_P0_S0_IN_B) { reg = FPC202_REG_IN_A_INT; bit = BIT(4 + offset); } else if (offset < FPC202_GPIO_P0_S0_OUT_A) { reg = FPC202_REG_IN_C_IN_B; bit = BIT(offset - FPC202_GPIO_P0_S0_IN_B); } else { reg = FPC202_REG_OUT_A_OUT_B_VAL; bit = BIT(offset - FPC202_GPIO_P0_S0_OUT_A); } ret = fpc202_read(priv, reg); if (ret < 0) return ret; return !!(((u8)ret) & bit); } static int fpc202_gpio_direction_input(struct gpio_chip *chip, unsigned int offset) { if (fpc202_gpio_get_dir(offset) == GPIO_LINE_DIRECTION_OUT) return -EINVAL; return 0; } static int fpc202_gpio_direction_output(struct gpio_chip *chip, unsigned int offset, int value) { struct fpc202_priv *priv = gpiochip_get_data(chip); int ret; u8 val; if (fpc202_gpio_get_dir(offset) == GPIO_LINE_DIRECTION_IN) return -EINVAL; fpc202_gpio_set(chip, offset, value); ret = fpc202_read(priv, FPC202_REG_OUT_A_OUT_B); if (ret < 0) return ret; val = (u8)ret | BIT(offset - FPC202_GPIO_P0_S0_OUT_A); return fpc202_write(priv, FPC202_REG_OUT_A_OUT_B, val); } /* * Set the translation table entry associated with a port and device number. * * Each downstream port of the FPC202 has two fixed aliases corresponding to * device numbers 0 and 1. If one of these aliases is found in an incoming I2C * transfer, it will be translated to the address given by the corresponding * translation table entry. */ static int fpc202_write_dev_addr(struct fpc202_priv *priv, u32 port_id, int dev_num, u16 addr) { int ret, reg_mod, reg_aux; u8 val; guard(mutex)(&priv->reg_dev_lock); reg_mod = FPC202_REG_MOD_DEV(port_id, dev_num); reg_aux = FPC202_REG_AUX_DEV(port_id, dev_num); val = addr & 0x7f; ret = fpc202_write(priv, reg_mod, val); if (ret) return ret; /* * The FPC202 datasheet is unclear about the role of the AUX registers. * Empirically, writing to them as well seems to be necessary for * address translation to function properly. */ ret = fpc202_write(priv, reg_aux, val); priv->addr_caches[port_id][dev_num] = val; return ret; } static int fpc202_attach_addr(struct i2c_atr *atr, u32 chan_id, u16 addr, u16 alias) { struct fpc202_priv *priv = i2c_atr_get_driver_data(atr); dev_dbg(&priv->client->dev, "attaching address 0x%02x to alias 0x%02x\n", addr, alias); return fpc202_write_dev_addr(priv, chan_id, fpc202_dev_num_from_alias(alias), addr); } static void fpc202_detach_addr(struct i2c_atr *atr, u32 chan_id, u16 addr) { struct fpc202_priv *priv = i2c_atr_get_driver_data(atr); int dev_num, reg_mod, val; for (dev_num = 0; dev_num < 2; dev_num++) { reg_mod = FPC202_REG_MOD_DEV(chan_id, dev_num); mutex_lock(&priv->reg_dev_lock); val = priv->addr_caches[chan_id][dev_num]; mutex_unlock(&priv->reg_dev_lock); if (val < 0) { dev_err(&priv->client->dev, "failed to read register 0x%x while detaching address 0x%02x\n", reg_mod, addr); return; } if (val == (addr & 0x7f)) { fpc202_write_dev_addr(priv, chan_id, dev_num, FPC202_REG_DEV_INVALID); return; } } } static const struct i2c_atr_ops fpc202_atr_ops = { .attach_addr = fpc202_attach_addr, .detach_addr = fpc202_detach_addr, }; static int fpc202_probe_port(struct fpc202_priv *priv, struct device_node *i2c_handle, int port_id) { u16 aliases[FPC202_ALIASES_PER_PORT] = { }; struct device *dev = &priv->client->dev; struct i2c_atr_adap_desc desc = { }; int ret = 0; desc.chan_id = port_id; desc.parent = dev; desc.bus_handle = of_node_to_fwnode(i2c_handle); desc.num_aliases = FPC202_ALIASES_PER_PORT; fpc202_fill_alias_table(priv->client, aliases, port_id); desc.aliases = aliases; ret = i2c_atr_add_adapter(priv->atr, &desc); if (ret) return ret; set_bit(port_id, priv->probed_ports); ret = fpc202_write_dev_addr(priv, port_id, 0, FPC202_REG_DEV_INVALID); if (ret) return ret; return fpc202_write_dev_addr(priv, port_id, 1, FPC202_REG_DEV_INVALID); } static void fpc202_remove_port(struct fpc202_priv *priv, int port_id) { i2c_atr_del_adapter(priv->atr, port_id); clear_bit(port_id, priv->probed_ports); } static int fpc202_probe(struct i2c_client *client) { struct device *dev = &client->dev; struct device_node *i2c_handle; struct fpc202_priv *priv; int ret, port_id; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; mutex_init(&priv->reg_dev_lock); priv->client = client; i2c_set_clientdata(client, priv); priv->en_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_HIGH); if (IS_ERR(priv->en_gpio)) { ret = PTR_ERR(priv->en_gpio); dev_err(dev, "failed to fetch enable GPIO! err %d\n", ret); goto destroy_mutex; } priv->gpio.label = "gpio-fpc202"; priv->gpio.base = -1; priv->gpio.direction_input = fpc202_gpio_direction_input; priv->gpio.direction_output = fpc202_gpio_direction_output; priv->gpio.set = fpc202_gpio_set; priv->gpio.get = fpc202_gpio_get; priv->gpio.ngpio = FPC202_GPIO_COUNT; priv->gpio.parent = dev; priv->gpio.owner = THIS_MODULE; ret = gpiochip_add_data(&priv->gpio, priv); if (ret) { priv->gpio.parent = NULL; dev_err(dev, "failed to add gpiochip err %d\n", ret); goto disable_gpio; } priv->atr = i2c_atr_new(client->adapter, dev, &fpc202_atr_ops, 2, 0); if (IS_ERR(priv->atr)) { ret = PTR_ERR(priv->atr); dev_err(dev, "failed to create i2c atr err %d\n", ret); goto disable_gpio; } i2c_atr_set_driver_data(priv->atr, priv); bitmap_zero(priv->probed_ports, FPC202_NUM_PORTS); for_each_child_of_node(dev->of_node, i2c_handle) { ret = of_property_read_u32(i2c_handle, "reg", &port_id); if (ret) { if (ret == -EINVAL) continue; dev_err(dev, "failed to read 'reg' property of child node, err %d\n", ret); goto unregister_chans; } if (port_id > FPC202_NUM_PORTS) { dev_err(dev, "port ID %d is out of range!\n", port_id); ret = -EINVAL; goto unregister_chans; } ret = fpc202_probe_port(priv, i2c_handle, port_id); if (ret) { dev_err(dev, "Failed to probe port %d, err %d\n", port_id, ret); goto unregister_chans; } } goto out; unregister_chans: for_each_set_bit(port_id, priv->probed_ports, FPC202_NUM_PORTS) fpc202_remove_port(priv, port_id); i2c_atr_delete(priv->atr); disable_gpio: fpc202_set_enable(priv, 0); gpiochip_remove(&priv->gpio); destroy_mutex: mutex_destroy(&priv->reg_dev_lock); out: return ret; } static void fpc202_remove(struct i2c_client *client) { struct fpc202_priv *priv = i2c_get_clientdata(client); int port_id; for_each_set_bit(port_id, priv->probed_ports, FPC202_NUM_PORTS) fpc202_remove_port(priv, port_id); mutex_destroy(&priv->reg_dev_lock); i2c_atr_delete(priv->atr); fpc202_set_enable(priv, 0); gpiochip_remove(&priv->gpio); } static const struct of_device_id fpc202_of_match[] = { { .compatible = "ti,fpc202" }, {} }; MODULE_DEVICE_TABLE(of, fpc202_of_match); static struct i2c_driver fpc202_driver = { .driver = { .name = "fpc202", .of_match_table = fpc202_of_match, }, .probe = fpc202_probe, .remove = fpc202_remove, }; module_i2c_driver(fpc202_driver); MODULE_AUTHOR("Romain Gantois <romain.gantois@bootlin.com>"); MODULE_DESCRIPTION("TI FPC202 Dual Port Controller driver"); MODULE_LICENSE("GPL"); MODULE_IMPORT_NS("I2C_ATR");
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