zephyr/drivers/entropy/entropy_litex.c
Tomasz Bursztyka e18fcbba5a device: Const-ify all device driver instance pointers
Now that device_api attribute is unmodified at runtime, as well as all
the other attributes, it is possible to switch all device driver
instance to be constant.

A coccinelle rule is used for this:

@r_const_dev_1
  disable optional_qualifier
@
@@
-struct device *
+const struct device *

@r_const_dev_2
 disable optional_qualifier
@
@@
-struct device * const
+const struct device *

Fixes #27399

Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
2020-09-02 13:48:13 +02:00

66 lines
1.4 KiB
C

/*
* Copyright (c) 2019 Antmicro <www.antmicro.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT litex_prbs
#include <device.h>
#include <drivers/entropy.h>
#include <errno.h>
#include <init.h>
#include <soc.h>
#include <string.h>
#include <zephyr.h>
#define PRBS_STATUS ((volatile uint32_t *)DT_INST_REG_ADDR(0))
#define PRBS_WIDTH DT_INST_REG_SIZE(0)
#define SUBREG_SIZE_BIT 8
static inline unsigned int prbs_read(volatile uint32_t *reg_status,
volatile uint32_t reg_width)
{
uint32_t shifted_data, shift, i;
uint32_t result = 0;
for (i = 0; i < reg_width; ++i) {
shifted_data = *(reg_status + i);
shift = (reg_width - i - 1) * SUBREG_SIZE_BIT;
result |= (shifted_data << shift);
}
return result;
}
static int entropy_prbs_get_entropy(const struct device *dev, uint8_t *buffer,
uint16_t length)
{
while (length > 0) {
size_t to_copy;
uint32_t value;
value = prbs_read(PRBS_STATUS, PRBS_WIDTH);
to_copy = MIN(length, sizeof(value));
memcpy(buffer, &value, to_copy);
buffer += to_copy;
length -= to_copy;
}
return 0;
}
static int entropy_prbs_init(const struct device *dev)
{
return 0;
}
static const struct entropy_driver_api entropy_prbs_api = {
.get_entropy = entropy_prbs_get_entropy
};
DEVICE_AND_API_INIT(entropy_prbs, DT_INST_LABEL(0),
entropy_prbs_init, NULL, NULL,
PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_DEVICE,
&entropy_prbs_api);