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i2c: add quirk checks to core

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Let the core do the checks if HW quirks prevent a transfer. Saves code
from drivers and adds consistency.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Tested-by: Ray Jui <rjui@broadcom.com>
Tested-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Tested-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Tested-By: Ludovic Desroches <ludovic.desroches@atmel.com>
This commit is contained in:
Wolfram Sang 2015-01-05 23:45:59 +01:00
parent 2187f03a95
commit b7f6258402
1 changed files with 62 additions and 0 deletions
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62
drivers/i2c/i2c-core.c
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@ -1929,6 +1929,65 @@ module_exit(i2c_exit);
* ----------------------------------------------------
*/
/* Check if val is exceeding the quirk IFF quirk is non 0 */
#define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk)))
static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg)
{
dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n",
err_msg, msg->addr, msg->len,
msg->flags & I2C_M_RD ? "read" : "write");
return -EOPNOTSUPP;
}
static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
const struct i2c_adapter_quirks *q = adap->quirks;
int max_num = q->max_num_msgs, i;
bool do_len_check = true;
if (q->flags & I2C_AQ_COMB) {
max_num = 2;
/* special checks for combined messages */
if (num == 2) {
if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD)
return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write");
if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD))
return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read");
if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr)
return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr");
if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len))
return i2c_quirk_error(adap, &msgs[0], "msg too long");
if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len))
return i2c_quirk_error(adap, &msgs[1], "msg too long");
do_len_check = false;
}
}
if (i2c_quirk_exceeded(num, max_num))
return i2c_quirk_error(adap, &msgs[0], "too many messages");
for (i = 0; i < num; i++) {
u16 len = msgs[i].len;
if (msgs[i].flags & I2C_M_RD) {
if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len))
return i2c_quirk_error(adap, &msgs[i], "msg too long");
} else {
if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len))
return i2c_quirk_error(adap, &msgs[i], "msg too long");
}
}
return 0;
}
/**
* __i2c_transfer - unlocked flavor of i2c_transfer
* @adap: Handle to I2C bus
@ -1946,6 +2005,9 @@ int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
unsigned long orig_jiffies;
int ret, try;
if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
return -EOPNOTSUPP;
/* i2c_trace_msg gets enabled when tracepoint i2c_transfer gets
* enabled. This is an efficient way of keeping the for-loop from
* being executed when not needed.