^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) * Microchip / Atmel SHA204A (I2C) driver.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (c) 2019 Linaro, Ltd. <ard.biesheuvel@linaro.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/delay.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/err.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/i2c.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/scatterlist.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/workqueue.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include "atmel-i2c.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) static void atmel_sha204a_rng_done(struct atmel_i2c_work_data *work_data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) void *areq, int status)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) struct atmel_i2c_client_priv *i2c_priv = work_data->ctx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) struct hwrng *rng = areq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) if (status)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) dev_warn_ratelimited(&i2c_priv->client->dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) "i2c transaction failed (%d)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) status);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) rng->priv = (unsigned long)work_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) atomic_dec(&i2c_priv->tfm_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) static int atmel_sha204a_rng_read_nonblocking(struct hwrng *rng, void *data,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) size_t max)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) struct atmel_i2c_client_priv *i2c_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) struct atmel_i2c_work_data *work_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) i2c_priv = container_of(rng, struct atmel_i2c_client_priv, hwrng);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) /* keep maximum 1 asynchronous read in flight at any time */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) if (!atomic_add_unless(&i2c_priv->tfm_count, 1, 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) if (rng->priv) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) work_data = (struct atmel_i2c_work_data *)rng->priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) max = min(sizeof(work_data->cmd.data), max);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) memcpy(data, &work_data->cmd.data, max);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) rng->priv = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) work_data = kmalloc(sizeof(*work_data), GFP_ATOMIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) if (!work_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) work_data->ctx = i2c_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) work_data->client = i2c_priv->client;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) max = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) atmel_i2c_init_random_cmd(&work_data->cmd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) atmel_i2c_enqueue(work_data, atmel_sha204a_rng_done, rng);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) return max;
^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 atmel_sha204a_rng_read(struct hwrng *rng, void *data, size_t max,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) bool wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) struct atmel_i2c_client_priv *i2c_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) struct atmel_i2c_cmd cmd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) if (!wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) return atmel_sha204a_rng_read_nonblocking(rng, data, max);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) i2c_priv = container_of(rng, struct atmel_i2c_client_priv, hwrng);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) atmel_i2c_init_random_cmd(&cmd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) ret = atmel_i2c_send_receive(i2c_priv->client, &cmd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) max = min(sizeof(cmd.data), max);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) memcpy(data, cmd.data, max);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) return max;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) static int atmel_sha204a_probe(struct i2c_client *client,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) const struct i2c_device_id *id)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) struct atmel_i2c_client_priv *i2c_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) ret = atmel_i2c_probe(client, id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) i2c_priv = i2c_get_clientdata(client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) memset(&i2c_priv->hwrng, 0, sizeof(i2c_priv->hwrng));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) i2c_priv->hwrng.name = dev_name(&client->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) i2c_priv->hwrng.read = atmel_sha204a_rng_read;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) i2c_priv->hwrng.quality = 1024;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) ret = devm_hwrng_register(&client->dev, &i2c_priv->hwrng);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) dev_warn(&client->dev, "failed to register RNG (%d)\n", ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) static int atmel_sha204a_remove(struct i2c_client *client)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) struct atmel_i2c_client_priv *i2c_priv = i2c_get_clientdata(client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) if (atomic_read(&i2c_priv->tfm_count)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) dev_err(&client->dev, "Device is busy\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) return -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) if (i2c_priv->hwrng.priv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) kfree((void *)i2c_priv->hwrng.priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) static const struct of_device_id atmel_sha204a_dt_ids[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) { .compatible = "atmel,atsha204a", },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) { /* sentinel */ }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) MODULE_DEVICE_TABLE(of, atmel_sha204a_dt_ids);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) static const struct i2c_device_id atmel_sha204a_id[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) { "atsha204a", 0 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) { /* sentinel */ }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) MODULE_DEVICE_TABLE(i2c, atmel_sha204a_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) static struct i2c_driver atmel_sha204a_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) .probe = atmel_sha204a_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) .remove = atmel_sha204a_remove,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) .id_table = atmel_sha204a_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) .driver.name = "atmel-sha204a",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) .driver.of_match_table = of_match_ptr(atmel_sha204a_dt_ids),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) static int __init atmel_sha204a_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) return i2c_add_driver(&atmel_sha204a_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) static void __exit atmel_sha204a_exit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) flush_scheduled_work();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) i2c_del_driver(&atmel_sha204a_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) module_init(atmel_sha204a_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) module_exit(atmel_sha204a_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) MODULE_LICENSE("GPL v2");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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