drivers: wifi: Fix QSPI frequency configuration for RPU wakeup

With the init/uninit changes for every transaction configuring lowest
clock for RPU wakup is broken, 24MHz (DTS) clock is used to wakeup RPU,
though it works, fix this by directly modifying the global QSPI
configuration and let init take care of configuring IFCONFIG1 register.

Signed-off-by: Krishna T <[email protected]>

Author: Krishna T

drivers/wifi/nrf700x/zephyr/src/qspi/src/qspi_if.c

@@ -101,17 +101,25 @@ struct qspi_nor_data {
 #endif /* CONFIG_MULTITHREADING */
 };
 
-static inline int qspi_freq_to_sckfreq(int freq)
+static inline int qspi_freq_mhz_to_sckfreq(int freq_m)
 {
+	if (freq_m > (NRF_QSPI_BASE_CLOCK_FREQ / MHZ(1))) {
+		return NRF_QSPI_FREQ_DIV1;
+	}
 #if defined(CONFIG_SOC_SERIES_NRF53X)
 	/* QSPIM (6-96MHz) : 192MHz / (2*(SCKFREQ + 1)) */
-	return ((192 / freq) / 2) - 1;
+	return ((192 / freq_m) / 2) - 1;
 #else
 	/* QSPIM (2-32MHz): 32 MHz / (SCKFREQ + 1) */
-	return (32 / freq) - 1;
+	return (32 / freq_m) - 1;
 #endif
 }
 
+static inline int qspi_dts_freq_to_sckfreq(void)
+{
+	/* DTS frequency is in HZ */
+	return qspi_freq_mhz_to_sckfreq(INST_0_SCK_FREQUENCY / MHZ(1));
+}
 
 static inline int qspi_get_mode(bool cpol, bool cpha)
 {
@@ -566,9 +574,7 @@ static inline void qspi_fill_init_struct(nrfx_qspi_config_t *initstruct)
 	initstruct->prot_if.dpmconfig = false;
 
 	/* Configure physical interface */
-	initstruct->phy_if.sck_freq = (INST_0_SCK_FREQUENCY > NRF_QSPI_BASE_CLOCK_FREQ) ?
-					      NRF_QSPI_FREQ_DIV1 :
-					      (NRF_QSPI_BASE_CLOCK_FREQ / INST_0_SCK_FREQUENCY) - 1;
+	initstruct->phy_if.sck_freq = qspi_dts_freq_to_sckfreq();
 	/* Using MHZ fails checkpatch constant check */
 	if (INST_0_SCK_FREQUENCY >= 16000000) {
 		qspi_config->qspi_slave_latency = 1;
@@ -978,7 +984,8 @@ int qspi_wait_while_rpu_awake(const struct device *dev)
 
 	/* Configure DTS settings */
 	if (val & RPU_AWAKE_BIT) {
-		nrf_qspi_ifconfig1_set(NRF_QSPI, &QSPIconfig.phy_if);
+		/* Restore QSPI clock frequency from DTS */
+		QSPIconfig.phy_if.sck_freq = qspi_dts_freq_to_sckfreq();
 	}
 
 	return val;
@@ -1048,14 +1055,9 @@ int qspi_WRSR2(const struct device *dev, uint8_t data)
 int qspi_cmd_wakeup_rpu(const struct device *dev, uint8_t data)
 {
 	int ret;
-	/* Use lowest 8MHz for waking up RPU */
-	const nrf_qspi_phy_conf_t qspi_phy_8mhz = {
-		.sck_freq = qspi_freq_to_sckfreq(8),
-		.sck_delay = QSPI_SCK_DELAY,
-		.spi_mode = NRF_QSPI_MODE_0
-	};
 
-	nrf_qspi_ifconfig1_set(NRF_QSPI, &qspi_phy_8mhz);
+	/* Waking RPU works reliably only with lowest frequency (8MHz) */
+	QSPIconfig.phy_if.sck_freq = qspi_freq_mhz_to_sckfreq(8);
 
 	ret = qspi_WRSR2(dev, data);