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spi: spi_nrfx_spim: limit clock frequency by inst

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Limit the maximum SPI frequency to that supported by the instance
hardware. This stops peripherals supporting >8MHz on slow instances
from wrapping around on the clock frequency for undefined behaviour.

Fixes #34402

Signed-off-by: Jordan Yates <jordan.yates@data61.csiro.au>
This commit is contained in:
Jordan Yates 2021-04-20 13:47:35 +10:00 • committed by Carles Cufí
commit ed20c06908
1 changed files with 8 additions and 2 deletions
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10
drivers/spi/spi_nrfx_spim.c
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@ -31,6 +31,7 @@ struct spi_nrfx_data {
struct spi_nrfx_config { struct spi_nrfx_config {
nrfx_spim_t spim; nrfx_spim_t spim;
size_t max_chunk_len; size_t max_chunk_len;
uint32_t max_freq;
nrfx_spim_config_t config; nrfx_spim_config_t config;
}; };
@ -108,6 +109,7 @@ static int configure(const struct device *dev,
{ {
struct spi_context *ctx = &get_dev_data(dev)->ctx; struct spi_context *ctx = &get_dev_data(dev)->ctx;
const nrfx_spim_t *spim = &get_dev_config(dev)->spim; const nrfx_spim_t *spim = &get_dev_config(dev)->spim;
nrf_spim_frequency_t freq;
if (spi_context_configured(ctx, spi_cfg)) { if (spi_context_configured(ctx, spi_cfg)) {
/* Already configured. No need to do it again. */ /* Already configured. No need to do it again. */
@ -144,11 +146,14 @@ static int configure(const struct device *dev,
ctx->config = spi_cfg; ctx->config = spi_cfg;
spi_context_cs_configure(ctx); spi_context_cs_configure(ctx);
/* Limit the frequency to that supported by the SPIM instance */
freq = get_nrf_spim_frequency(MIN(spi_cfg->frequency,
get_dev_config(dev)->max_freq));
nrf_spim_configure(spim->p_reg, nrf_spim_configure(spim->p_reg,
get_nrf_spim_mode(spi_cfg->operation), get_nrf_spim_mode(spi_cfg->operation),
get_nrf_spim_bit_order(spi_cfg->operation)); get_nrf_spim_bit_order(spi_cfg->operation));
nrf_spim_frequency_set(spim->p_reg, nrf_spim_frequency_set(spim->p_reg, freq);
get_nrf_spim_frequency(spi_cfg->frequency));
return 0; return 0;
} }
@ -424,6 +429,7 @@ static int spim_nrfx_pm_control(const struct device *dev,
static const struct spi_nrfx_config spi_##idx##z_config = { \ static const struct spi_nrfx_config spi_##idx##z_config = { \
.spim = NRFX_SPIM_INSTANCE(idx), \ .spim = NRFX_SPIM_INSTANCE(idx), \
.max_chunk_len = (1 << SPIM##idx##_EASYDMA_MAXCNT_SIZE) - 1, \ .max_chunk_len = (1 << SPIM##idx##_EASYDMA_MAXCNT_SIZE) - 1, \
.max_freq = SPIM##idx##_MAX_DATARATE * 1000000, \
.config = { \ .config = { \
.sck_pin = SPIM_PROP(idx, sck_pin), \ .sck_pin = SPIM_PROP(idx, sck_pin), \
.mosi_pin = SPIM_PROP(idx, mosi_pin), \ .mosi_pin = SPIM_PROP(idx, mosi_pin), \