^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0+
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) //
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) // Gateworks I2C PLD GPIO expander
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) //
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) // Copyright (C) 2019 Linus Walleij <linus.walleij@linaro.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) //
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) // Based on code and know-how from the OpenWrt driver:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) // Copyright (C) 2009 Gateworks Corporation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) // Authors: Chris Lang, Imre Kaloz
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/bits.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/gpio/driver.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/i2c.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) * struct gw_pld - State container for Gateworks PLD
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) * @chip: GPIO chip instance
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) * @client: I2C client
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) * @out: shadow register for the output bute
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) struct gw_pld {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) struct gpio_chip chip;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) struct i2c_client *client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) u8 out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * The Gateworks I2C PLD chip only expose one read and one write register.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) * Writing a "one" bit (to match the reset state) lets that pin be used as an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * input. It is an open-drain model.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) static int gw_pld_input8(struct gpio_chip *gc, unsigned offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) struct gw_pld *gw = gpiochip_get_data(gc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) gw->out |= BIT(offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) return i2c_smbus_write_byte(gw->client, gw->out);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) static int gw_pld_get8(struct gpio_chip *gc, unsigned offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) struct gw_pld *gw = gpiochip_get_data(gc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) s32 val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) val = i2c_smbus_read_byte(gw->client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) return (val < 0) ? 0 : !!(val & BIT(offset));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) static int gw_pld_output8(struct gpio_chip *gc, unsigned offset, int value)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) struct gw_pld *gw = gpiochip_get_data(gc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) if (value)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) gw->out |= BIT(offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) gw->out &= ~BIT(offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) return i2c_smbus_write_byte(gw->client, gw->out);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) static void gw_pld_set8(struct gpio_chip *gc, unsigned offset, int value)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) gw_pld_output8(gc, offset, value);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) static int gw_pld_probe(struct i2c_client *client,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) const struct i2c_device_id *id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) struct device *dev = &client->dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) struct device_node *np = dev->of_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) struct gw_pld *gw;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) gw = devm_kzalloc(dev, sizeof(*gw), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) if (!gw)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) gw->chip.base = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) gw->chip.can_sleep = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) gw->chip.parent = dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) gw->chip.of_node = np;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) gw->chip.owner = THIS_MODULE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) gw->chip.label = dev_name(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) gw->chip.ngpio = 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) gw->chip.direction_input = gw_pld_input8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) gw->chip.get = gw_pld_get8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) gw->chip.direction_output = gw_pld_output8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) gw->chip.set = gw_pld_set8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) gw->client = client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) * The Gateworks I2C PLD chip does not properly send the acknowledge
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * bit at all times, but we can still use the standard i2c_smbus
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) * functions by simply ignoring this bit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) client->flags |= I2C_M_IGNORE_NAK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) gw->out = 0xFF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) i2c_set_clientdata(client, gw);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) ret = devm_gpiochip_add_data(dev, &gw->chip, gw);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) dev_info(dev, "registered Gateworks PLD GPIO device\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) static const struct i2c_device_id gw_pld_id[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) { "gw-pld", },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) MODULE_DEVICE_TABLE(i2c, gw_pld_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) static const struct of_device_id gw_pld_dt_ids[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) { .compatible = "gateworks,pld-gpio", },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) { },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) MODULE_DEVICE_TABLE(of, gw_pld_dt_ids);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) static struct i2c_driver gw_pld_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) .driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) .name = "gw_pld",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) .of_match_table = gw_pld_dt_ids,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) .probe = gw_pld_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) .id_table = gw_pld_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) module_i2c_driver(gw_pld_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) MODULE_LICENSE("GPL");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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