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drivers: entropy: sam: Add support for sam0

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SAM0 uses the same TRNG as SAM, so it's trivial to add support
for this line of MCUs.

Signed-off-by: Benjamin Valentin <benpicco@googlemail.com>
This commit is contained in:
Benjamin Valentin 2020-01-13 18:30:28 +01:00 • committed by Ioannis Glaropoulos
commit 633d57508f
2 changed files with 33 additions and 7 deletions
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2
drivers/entropy/Kconfig.sam
View file

@ -5,7 +5,7 @@
config ENTROPY_SAM_RNG
bool "Atmel SAM MCU Family True Random Number Generator (TRNG) Driver"
depends on SOC_FAMILY_SAM
depends on SOC_FAMILY_SAM || SOC_FAMILY_SAM0
select ENTROPY_HAS_DRIVER
select HAS_DTS_ENTROPY
help

38
drivers/entropy/entropy_sam.c
View file

@ -18,6 +18,25 @@ struct trng_sam_dev_cfg {
#define DEV_CFG(dev) \
((const struct trng_sam_dev_cfg *const)(dev)->config->config_info)
static inline bool _ready(Trng * const trng)
{
#ifdef TRNG_ISR_DATRDY
return trng->TRNG_ISR & TRNG_ISR_DATRDY;
#else
return trng->INTFLAG.bit.DATARDY;
#endif
}
static inline uint32_t _data(Trng * const trng)
{
#ifdef REG_TRNG_DATA
(void) trng;
return TRNG->DATA.reg;
#else
return trng->TRNG_ODATA;
#endif
}
static int entropy_sam_wait_ready(Trng * const trng, u32_t flags)
{
/* According to the reference manual, the generator provides
@ -31,7 +50,7 @@ static int entropy_sam_wait_ready(Trng * const trng, u32_t flags)
*/
int timeout = 1000000;
while (!(trng->TRNG_ISR & TRNG_ISR_DATRDY)) {
while (!_ready(trng)) {
if (timeout-- == 0) {
return -ETIMEDOUT;
}
@ -66,7 +85,7 @@ static int entropy_sam_get_entropy_internal(struct device *dev, u8_t *buffer,
return res;
}
value = trng->TRNG_ODATA;
value = _data(trng);
to_copy = MIN(length, sizeof(value));
memcpy(buffer, &value, to_copy);
@ -99,13 +118,13 @@ static int entropy_sam_get_entropy_isr(struct device *dev, u8_t *buffer,
size_t to_copy;
u32_t value;
if (!(trng->TRNG_ISR & TRNG_ISR_DATRDY)) {
if (!_ready(trng)) {
/* Data not ready */
break;
}
value = trng->TRNG_ODATA;
value = _data(trng);
to_copy = MIN(length, sizeof(value));
memcpy(buffer, &value, to_copy);
@ -135,12 +154,19 @@ static int entropy_sam_init(struct device *dev)
{
Trng *const trng = DEV_CFG(dev)->regs;
#ifdef MCLK
/* Enable the MCLK */
MCLK->APBCMASK.bit.TRNG_ = 1;
/* Enable the TRNG */
trng->CTRLA.bit.ENABLE = 1;
#else
/* Enable the user interface clock */
soc_pmc_peripheral_enable(DT_ENTROPY_SAM_TRNG_PERIPHERAL_ID);
/* Enable the TRNG */
trng->TRNG_CR = TRNG_CR_KEY_PASSWD | TRNG_CR_ENABLE;
#endif
return 0;
}
@ -150,7 +176,7 @@ static const struct entropy_driver_api entropy_sam_api = {
};
static const struct trng_sam_dev_cfg trng_sam_cfg = {
.regs = (Trng *)DT_ENTROPY_SAM_TRNG_BASE_ADDRESS,
.regs = (Trng *)DT_INST_0_ATMEL_SAM_TRNG_BASE_ADDRESS,
};
DEVICE_AND_API_INIT(entropy_sam, CONFIG_ENTROPY_NAME,