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drivers: flash: nrf_qspi_nor: Handle properly multiple XIP users

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Add reference counting in nrf_qspi_nor_xip_enable() so that XIP is
kept enabled as long as there is at least one user that needs it
(boot time enabling done with CONFIG_NORDIC_QSPI_NOR_XIP also counts).

Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>
This commit is contained in:
Andrzej Głąbek 2025-05-23 09:32:58 +02:00 • committed by Benjamin Cabé
commit 2d9ede3852
1 changed files with 42 additions and 23 deletions
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65
drivers/flash/nrf_qspi_nor.c
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@ -41,7 +41,7 @@ struct qspi_nor_data {
*/ */
volatile bool ready; volatile bool ready;
#endif /* CONFIG_MULTITHREADING */ #endif /* CONFIG_MULTITHREADING */
bool xip_enabled; uint32_t xip_users;
}; };
struct qspi_nor_config { struct qspi_nor_config {
@ -313,7 +313,7 @@ static void qspi_acquire(const struct device *dev)
qspi_lock(dev); qspi_lock(dev);
if (!dev_data->xip_enabled) { if (dev_data->xip_users == 0) {
qspi_clock_div_change(); qspi_clock_div_change();
pm_device_busy_set(dev); pm_device_busy_set(dev);
@ -331,7 +331,7 @@ static void qspi_release(const struct device *dev)
deactivate = atomic_dec(&dev_data->usage_count) == 1; deactivate = atomic_dec(&dev_data->usage_count) == 1;
#endif #endif
if (!dev_data->xip_enabled) { if (dev_data->xip_users == 0) {
qspi_clock_div_restore(); qspi_clock_div_restore();
if (deactivate) { if (deactivate) {
@ -1344,35 +1344,54 @@ static int qspi_nor_pm_action(const struct device *dev,
} }
#endif /* CONFIG_PM_DEVICE */ #endif /* CONFIG_PM_DEVICE */
static void on_xip_enable(const struct device *dev)
{
#if NRF_QSPI_HAS_XIPEN
nrf_qspi_xip_set(NRF_QSPI, true);
#endif
(void)nrfx_qspi_activate(false);
}
static void on_xip_disable(const struct device *dev)
{
/* It turns out that when the QSPI peripheral is deactivated
* after a XIP transaction, it cannot be later successfully
* reactivated and an attempt to perform another XIP transaction
* results in the CPU being hung; even a debug session cannot be
* started then and the SoC has to be recovered.
* As a workaround, at least until the cause of such behavior
* is fully clarified, perform a simple non-XIP transaction
* (a read of the status register) before deactivating the QSPI.
* This prevents the issue from occurring.
*/
(void)qspi_rdsr(dev, 1);
#if NRF_QSPI_HAS_XIPEN
nrf_qspi_xip_set(NRF_QSPI, false);
#endif
}
void z_impl_nrf_qspi_nor_xip_enable(const struct device *dev, bool enable) void z_impl_nrf_qspi_nor_xip_enable(const struct device *dev, bool enable)
{ {
struct qspi_nor_data *dev_data = dev->data; struct qspi_nor_data *dev_data = dev->data;
if (dev_data->xip_enabled == enable) {
return;
}
qspi_acquire(dev); qspi_acquire(dev);
#if NRF_QSPI_HAS_XIPEN
nrf_qspi_xip_set(NRF_QSPI, enable);
#endif
if (enable) { if (enable) {
(void)nrfx_qspi_activate(false); if (dev_data->xip_users == 0) {
on_xip_enable(dev);
}
++dev_data->xip_users;
} else if (dev_data->xip_users == 0) {
LOG_ERR("Unbalanced XIP disabling");
} else { } else {
/* It turns out that when the QSPI peripheral is deactivated --dev_data->xip_users;
* after a XIP transaction, it cannot be later successfully
* reactivated and an attempt to perform another XIP transaction if (dev_data->xip_users == 0) {
* results in the CPU being hung; even a debug session cannot be on_xip_disable(dev);
* started then and the SoC has to be recovered. }
* As a workaround, at least until the cause of such behavior
* is fully clarified, perform a simple non-XIP transaction
* (a read of the status register) before deactivating the QSPI.
* This prevents the issue from occurring.
*/
(void)qspi_rdsr(dev, 1);
} }
dev_data->xip_enabled = enable;
qspi_release(dev); qspi_release(dev);
} }