u-boot-brain/drivers/misc/atsha204a-i2c.c
Simon Glass 41575d8e4c dm: treewide: Rename auto_alloc_size members to be shorter
This construct is quite long-winded. In earlier days it made some sense
since auto-allocation was a strange concept. But with driver model now
used pretty universally, we can shorten this to 'auto'. This reduces
verbosity and makes it easier to read.

Coincidentally it also ensures that every declaration is on one line,
thus making dtoc's job easier.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-12-13 08:00:25 -07:00

412 lines
11 KiB
C

/*
* I2C Driver for Atmel ATSHA204 over I2C
*
* Copyright (C) 2014 Josh Datko, Cryptotronix, jbd@cryptotronix.com
* 2016 Tomas Hlavacek, CZ.NIC, tmshlvck@gmail.com
* 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <common.h>
#include <dm.h>
#include <i2c.h>
#include <errno.h>
#include <atsha204a-i2c.h>
#include <log.h>
#include <linux/delay.h>
#include <u-boot/crc.h>
#define ATSHA204A_TWLO 60
#define ATSHA204A_TRANSACTION_TIMEOUT 100000
#define ATSHA204A_TRANSACTION_RETRY 5
#define ATSHA204A_EXECTIME 5000
DECLARE_GLOBAL_DATA_PTR;
/*
* The ATSHA204A uses an (to me) unknown CRC-16 algorithm.
* The Reveng CRC-16 catalogue does not contain it.
*
* Because in Atmel's documentation only a primitive implementation
* can be found, I have implemented this one with lookup table.
*/
/*
* This is the code that computes the table below:
*
* int i, j;
* for (i = 0; i < 256; ++i) {
* u8 c = 0;
* for (j = 0; j < 8; ++j) {
* c = (c << 1) | ((i >> j) & 1);
* }
* bitreverse_table[i] = c;
* }
*/
static u8 const bitreverse_table[256] = {
0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0,
0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0,
0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8,
0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8,
0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4,
0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4,
0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec,
0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc,
0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2,
0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2,
0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea,
0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa,
0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6,
0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6,
0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee,
0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe,
0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1,
0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1,
0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9,
0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9,
0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5,
0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5,
0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed,
0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd,
0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3,
0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3,
0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb,
0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb,
0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7,
0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7,
0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef,
0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff,
};
/*
* This is the code that computes the table below:
*
* int i, j;
* for (i = 0; i < 256; ++i) {
* u16 c = i << 8;
* for (j = 0; j < 8; ++j) {
* int b = c >> 15;
* c <<= 1;
* if (b)
* c ^= 0x8005;
* }
* crc16_table[i] = c;
* }
*/
static u16 const crc16_table[256] = {
0x0000, 0x8005, 0x800f, 0x000a, 0x801b, 0x001e, 0x0014, 0x8011,
0x8033, 0x0036, 0x003c, 0x8039, 0x0028, 0x802d, 0x8027, 0x0022,
0x8063, 0x0066, 0x006c, 0x8069, 0x0078, 0x807d, 0x8077, 0x0072,
0x0050, 0x8055, 0x805f, 0x005a, 0x804b, 0x004e, 0x0044, 0x8041,
0x80c3, 0x00c6, 0x00cc, 0x80c9, 0x00d8, 0x80dd, 0x80d7, 0x00d2,
0x00f0, 0x80f5, 0x80ff, 0x00fa, 0x80eb, 0x00ee, 0x00e4, 0x80e1,
0x00a0, 0x80a5, 0x80af, 0x00aa, 0x80bb, 0x00be, 0x00b4, 0x80b1,
0x8093, 0x0096, 0x009c, 0x8099, 0x0088, 0x808d, 0x8087, 0x0082,
0x8183, 0x0186, 0x018c, 0x8189, 0x0198, 0x819d, 0x8197, 0x0192,
0x01b0, 0x81b5, 0x81bf, 0x01ba, 0x81ab, 0x01ae, 0x01a4, 0x81a1,
0x01e0, 0x81e5, 0x81ef, 0x01ea, 0x81fb, 0x01fe, 0x01f4, 0x81f1,
0x81d3, 0x01d6, 0x01dc, 0x81d9, 0x01c8, 0x81cd, 0x81c7, 0x01c2,
0x0140, 0x8145, 0x814f, 0x014a, 0x815b, 0x015e, 0x0154, 0x8151,
0x8173, 0x0176, 0x017c, 0x8179, 0x0168, 0x816d, 0x8167, 0x0162,
0x8123, 0x0126, 0x012c, 0x8129, 0x0138, 0x813d, 0x8137, 0x0132,
0x0110, 0x8115, 0x811f, 0x011a, 0x810b, 0x010e, 0x0104, 0x8101,
0x8303, 0x0306, 0x030c, 0x8309, 0x0318, 0x831d, 0x8317, 0x0312,
0x0330, 0x8335, 0x833f, 0x033a, 0x832b, 0x032e, 0x0324, 0x8321,
0x0360, 0x8365, 0x836f, 0x036a, 0x837b, 0x037e, 0x0374, 0x8371,
0x8353, 0x0356, 0x035c, 0x8359, 0x0348, 0x834d, 0x8347, 0x0342,
0x03c0, 0x83c5, 0x83cf, 0x03ca, 0x83db, 0x03de, 0x03d4, 0x83d1,
0x83f3, 0x03f6, 0x03fc, 0x83f9, 0x03e8, 0x83ed, 0x83e7, 0x03e2,
0x83a3, 0x03a6, 0x03ac, 0x83a9, 0x03b8, 0x83bd, 0x83b7, 0x03b2,
0x0390, 0x8395, 0x839f, 0x039a, 0x838b, 0x038e, 0x0384, 0x8381,
0x0280, 0x8285, 0x828f, 0x028a, 0x829b, 0x029e, 0x0294, 0x8291,
0x82b3, 0x02b6, 0x02bc, 0x82b9, 0x02a8, 0x82ad, 0x82a7, 0x02a2,
0x82e3, 0x02e6, 0x02ec, 0x82e9, 0x02f8, 0x82fd, 0x82f7, 0x02f2,
0x02d0, 0x82d5, 0x82df, 0x02da, 0x82cb, 0x02ce, 0x02c4, 0x82c1,
0x8243, 0x0246, 0x024c, 0x8249, 0x0258, 0x825d, 0x8257, 0x0252,
0x0270, 0x8275, 0x827f, 0x027a, 0x826b, 0x026e, 0x0264, 0x8261,
0x0220, 0x8225, 0x822f, 0x022a, 0x823b, 0x023e, 0x0234, 0x8231,
0x8213, 0x0216, 0x021c, 0x8219, 0x0208, 0x820d, 0x8207, 0x0202,
};
static inline u16 crc16_byte(u16 crc, const u8 data)
{
u16 t = crc16_table[((crc >> 8) ^ bitreverse_table[data]) & 0xff];
return ((crc << 8) ^ t);
}
static u16 atsha204a_crc16(const u8 *buffer, size_t len)
{
u16 crc = 0;
while (len--)
crc = crc16_byte(crc, *buffer++);
return cpu_to_le16(crc);
}
static int atsha204a_send(struct udevice *dev, const u8 *buf, u8 len)
{
fdt_addr_t *priv = dev_get_priv(dev);
struct i2c_msg msg;
msg.addr = *priv;
msg.flags = I2C_M_STOP;
msg.len = len;
msg.buf = (u8 *) buf;
return dm_i2c_xfer(dev, &msg, 1);
}
static int atsha204a_recv(struct udevice *dev, u8 *buf, u8 len)
{
fdt_addr_t *priv = dev_get_priv(dev);
struct i2c_msg msg;
msg.addr = *priv;
msg.flags = I2C_M_RD | I2C_M_STOP;
msg.len = len;
msg.buf = (u8 *) buf;
return dm_i2c_xfer(dev, &msg, 1);
}
static int atsha204a_recv_resp(struct udevice *dev,
struct atsha204a_resp *resp)
{
int res;
u16 resp_crc, computed_crc;
u8 *p = (u8 *) resp;
res = atsha204a_recv(dev, p, 4);
if (res)
return res;
if (resp->length > 4) {
if (resp->length > sizeof(*resp))
return -EMSGSIZE;
res = atsha204a_recv(dev, p + 4, resp->length - 4);
if (res)
return res;
}
resp_crc = (u16) p[resp->length - 2]
| (((u16) p[resp->length - 1]) << 8);
computed_crc = atsha204a_crc16(p, resp->length - 2);
if (resp_crc != computed_crc) {
debug("Invalid checksum in ATSHA204A response\n");
return -EBADMSG;
}
return 0;
}
int atsha204a_wakeup(struct udevice *dev)
{
u8 req[4];
struct atsha204a_resp resp;
int try, res;
debug("Waking up ATSHA204A\n");
for (try = 1; try <= 10; ++try) {
debug("Try %i... ", try);
memset(req, 0, 4);
res = atsha204a_send(dev, req, 4);
if (res) {
debug("failed on I2C send, trying again\n");
continue;
}
udelay(ATSHA204A_TWLO);
res = atsha204a_recv_resp(dev, &resp);
if (res) {
debug("failed on receiving response, ending\n");
return res;
}
if (resp.code != ATSHA204A_STATUS_AFTER_WAKE) {
debug ("failed (responce code = %02x), ending\n",
resp.code);
return -EBADMSG;
}
debug("success\n");
break;
}
return 0;
}
int atsha204a_idle(struct udevice *dev)
{
int res;
u8 req = ATSHA204A_FUNC_IDLE;
res = atsha204a_send(dev, &req, 1);
if (res)
debug("Failed putting ATSHA204A idle\n");
return res;
}
int atsha204a_sleep(struct udevice *dev)
{
int res;
u8 req = ATSHA204A_FUNC_IDLE;
res = atsha204a_send(dev, &req, 1);
if (res)
debug("Failed putting ATSHA204A to sleep\n");
return res;
}
static int atsha204a_transaction(struct udevice *dev, struct atsha204a_req *req,
struct atsha204a_resp *resp)
{
int res, timeout = ATSHA204A_TRANSACTION_TIMEOUT;
res = atsha204a_send(dev, (u8 *) req, req->length + 1);
if (res) {
debug("ATSHA204A transaction send failed\n");
return -EBUSY;
}
do {
res = atsha204a_recv_resp(dev, resp);
if (!res || res == -EMSGSIZE || res == -EBADMSG)
break;
debug("ATSHA204A transaction polling for response "
"(timeout = %d)\n", timeout);
udelay(ATSHA204A_EXECTIME);
timeout -= ATSHA204A_EXECTIME;
} while (timeout > 0);
if (timeout <= 0) {
debug("ATSHA204A transaction timed out\n");
return -ETIMEDOUT;
}
return res;
}
static void atsha204a_req_crc32(struct atsha204a_req *req)
{
u8 *p = (u8 *) req;
u16 computed_crc;
u16 *crc_ptr = (u16 *) &p[req->length - 1];
/* The buffer to crc16 starts at byte 1, not 0 */
computed_crc = atsha204a_crc16(p + 1, req->length - 2);
*crc_ptr = cpu_to_le16(computed_crc);
}
int atsha204a_read(struct udevice *dev, enum atsha204a_zone zone, bool read32,
u16 addr, u8 *buffer)
{
int res, retry = ATSHA204A_TRANSACTION_RETRY;
struct atsha204a_req req;
struct atsha204a_resp resp;
req.function = ATSHA204A_FUNC_COMMAND;
req.length = 7;
req.command = ATSHA204A_CMD_READ;
req.param1 = (u8) zone;
if (read32)
req.param1 |= 0x80;
req.param2 = cpu_to_le16(addr);
atsha204a_req_crc32(&req);
do {
res = atsha204a_transaction(dev, &req, &resp);
if (!res)
break;
debug("ATSHA204A read retry (%d)\n", retry);
retry--;
atsha204a_wakeup(dev);
} while (retry >= 0);
if (res) {
debug("ATSHA204A read failed\n");
return res;
}
if (resp.length != (read32 ? 32 : 4) + 3) {
debug("ATSHA204A read bad response length (%d)\n",
resp.length);
return -EBADMSG;
}
memcpy(buffer, ((u8 *) &resp) + 1, read32 ? 32 : 4);
return 0;
}
int atsha204a_get_random(struct udevice *dev, u8 *buffer, size_t max)
{
int res;
struct atsha204a_req req;
struct atsha204a_resp resp;
req.function = ATSHA204A_FUNC_COMMAND;
req.length = 7;
req.command = ATSHA204A_CMD_RANDOM;
req.param1 = 1;
req.param2 = 0;
/* We do not have to compute the checksum dynamically */
req.data[0] = 0x27;
req.data[1] = 0x47;
res = atsha204a_transaction(dev, &req, &resp);
if (res) {
debug("ATSHA204A random transaction failed\n");
return res;
}
memcpy(buffer, ((u8 *) &resp) + 1, max >= 32 ? 32 : max);
return 0;
}
static int atsha204a_ofdata_to_platdata(struct udevice *dev)
{
fdt_addr_t *priv = dev_get_priv(dev);
fdt_addr_t addr;
addr = fdtdec_get_addr(gd->fdt_blob, dev_of_offset(dev), "reg");
if (addr == FDT_ADDR_T_NONE) {
debug("Can't get ATSHA204A I2C base address\n");
return -ENXIO;
}
*priv = addr;
return 0;
}
static const struct udevice_id atsha204a_ids[] = {
{ .compatible = "atmel,atsha204a" },
{ }
};
U_BOOT_DRIVER(atsha204) = {
.name = "atsha204",
.id = UCLASS_MISC,
.of_match = atsha204a_ids,
.ofdata_to_platdata = atsha204a_ofdata_to_platdata,
.priv_auto = sizeof(fdt_addr_t),
};