io timer: remove some fields from io_timers_t and split out channel indexes

- reduces amount of board configuration required
- removes the cyclic dependency between io_timers_t and timer_io_channels_t

Fixes a bug in the fmuk66-v3 config: the 2. timer has 3 channels associated
not 2.
Fixes a bug in the modelai config: the 2. timer has 4 channels associated.

platforms/nuttx/src/px4/nxp/kinetis/include/px4_arch/io_timer.h

@@ -82,11 +82,18 @@ typedef struct io_timers_t {
 	uint32_t	clock_register;      /* SIM_SCGCn */
 	uint32_t	clock_bit;           /* SIM_SCGCn bit pos */
 	uint32_t	vectorno;            /* IRQ number */
-	uint32_t    first_channel_index; /* 0 based index in timer_io_channels */
-	uint32_t    last_channel_index;  /* 0 based index in timer_io_channels */
-	xcpt_t      handler;
 } io_timers_t;
 
+typedef struct io_timers_channel_mapping_element_t {
+	uint32_t first_channel_index;
+	uint32_t channel_count;
+} io_timers_channel_mapping_element_t;
+
+/* mapping for each io_timers to timer_io_channels */
+typedef struct io_timers_channel_mapping_t {
+	io_timers_channel_mapping_element_t element[MAX_IO_TIMERS];
+} io_timers_channel_mapping_t;
+
 /* array of channels in logical order */
 typedef struct timer_io_channels_t {
 	uint32_t	gpio_out;            /* The timer channel GPIO for PWM */
@@ -104,16 +111,13 @@ typedef void (*channel_handler_t)(void *context, const io_timers_t *timer, uint3
 
 /* supplied by board-specific code */
 __EXPORT extern const io_timers_t io_timers[MAX_IO_TIMERS];
+__EXPORT extern const io_timers_channel_mapping_t io_timers_channel_mapping;
 __EXPORT extern const timer_io_channels_t timer_io_channels[MAX_TIMER_IO_CHANNELS];
 
 __EXPORT extern const io_timers_t led_pwm_timers[MAX_LED_TIMERS];
 __EXPORT extern const timer_io_channels_t led_pwm_channels[MAX_TIMER_LED_CHANNELS];
 
 __EXPORT extern io_timer_channel_allocation_t allocations[IOTimerChanModeSize];
-__EXPORT int io_timer_handler0(int irq, void *context, void *arg);
-__EXPORT int io_timer_handler1(int irq, void *context, void *arg);
-__EXPORT int io_timer_handler2(int irq, void *context, void *arg);
-__EXPORT int io_timer_handler3(int irq, void *context, void *arg);
 
 __EXPORT int io_timer_channel_init(unsigned channel, io_timer_channel_mode_t mode,
 				   channel_handler_t channel_handler, void *context);

platforms/nuttx/src/px4/nxp/kinetis/io_pins/io_timer.c

@@ -62,6 +62,16 @@
 #include "hardware/kinetis_sim.h"
 #include "hardware/kinetis_ftm.h"
 
+
+static int io_timer_handler0(int irq, void *context, void *arg);
+static int io_timer_handler1(int irq, void *context, void *arg);
+static int io_timer_handler2(int irq, void *context, void *arg);
+static int io_timer_handler3(int irq, void *context, void *arg);
+static int io_timer_handler4(int irq, void *context, void *arg);
+static int io_timer_handler5(int irq, void *context, void *arg);
+static int io_timer_handler6(int irq, void *context, void *arg);
+static int io_timer_handler7(int irq, void *context, void *arg);
+
 /* The FTM pre-scalers are limited to Divide by 2^n where n={1-7}
  * Therefore we use Y1 at 16 Mhz to drive FTM_CLKIN0 (PCT12)
  * and use this at a 16Mhz clock for FTM0, FTM2 and FTM3.
@@ -184,7 +194,10 @@ static int io_timer_handler(uint16_t timer_index)
 
 	/* Iterate over the timer_io_channels table */
 
-	for (unsigned chan_index = tmr->first_channel_index; chan_index <= tmr->last_channel_index; chan_index++) {
+	uint32_t first_channel_index = io_timers_channel_mapping.element[timer_index].first_channel_index;
+	uint32_t last_channel_index = first_channel_index + io_timers_channel_mapping.element[timer_index].channel_count;
+
+	for (unsigned chan_index = first_channel_index; chan_index < last_channel_index; chan_index++) {
 
 		uint16_t chan = 1 << chan_index;
 
@@ -216,26 +229,39 @@ static int io_timer_handler(uint16_t timer_index)
 
 int io_timer_handler0(int irq, void *context, void *arg)
 {
-
 	return io_timer_handler(0);
 }
 
 int io_timer_handler1(int irq, void *context, void *arg)
 {
 	return io_timer_handler(1);
-
 }
 
 int io_timer_handler2(int irq, void *context, void *arg)
 {
 	return io_timer_handler(2);
-
 }
 
 int io_timer_handler3(int irq, void *context, void *arg)
 {
 	return io_timer_handler(3);
+}
 
+int io_timer_handler4(int irq, void *context, void *arg)
+{
+	return io_timer_handler(4);
+}
+int io_timer_handler5(int irq, void *context, void *arg)
+{
+	return io_timer_handler(5);
+}
+int io_timer_handler6(int irq, void *context, void *arg)
+{
+	return io_timer_handler(6);
+}
+int io_timer_handler7(int irq, void *context, void *arg)
+{
+	return io_timer_handler(7);
 }
 
 static inline int validate_timer_index(unsigned timer)
@@ -269,17 +295,6 @@ static inline int channels_timer(unsigned channel)
 	return timer_io_channels[channel].timer_index;
 }
 
-static inline int get_timers_firstchannels(unsigned timer)
-{
-	int channel = -1;
-
-	if (validate_timer_index(timer) == 0) {
-		channel = timer_io_channels[io_timers[timer].first_channel_index].timer_channel;
-	}
-
-	return channel;
-}
-
 static uint32_t get_timer_channels(unsigned timer)
 {
 	uint32_t channels = 0;
@@ -290,11 +305,13 @@ static uint32_t get_timer_channels(unsigned timer)
 
 	} else {
 		if (channels_cache[timer] == 0) {
-			const io_timers_t *tmr = &io_timers[timer];
 
 			/* Gather the channel bits that belong to the timer */
 
-			for (unsigned chan_index = tmr->first_channel_index; chan_index <= tmr->last_channel_index; chan_index++) {
+			uint32_t first_channel_index = io_timers_channel_mapping.element[timer].first_channel_index;
+			uint32_t last_channel_index = first_channel_index + io_timers_channel_mapping.element[timer].channel_count;
+
+			for (unsigned chan_index = first_channel_index; chan_index < last_channel_index; chan_index++) {
 				channels |= 1 << chan_index;
 			}
 
@@ -577,10 +594,35 @@ int io_timer_init_timer(unsigned timer)
 		 * Note that the timer is left disabled with IRQ subs installed
 		 * and active but DEIR bits are not set.
 		 */
+		xcpt_t handler;
 
-		irq_attach(io_timers[timer].vectorno, io_timers[timer].handler, NULL);
+		switch (timer) {
+		case 0: handler = io_timer_handler0; break;
 
-		up_enable_irq(io_timers[timer].vectorno);
+		case 1: handler = io_timer_handler1; break;
+
+		case 2: handler = io_timer_handler2; break;
+
+		case 3: handler = io_timer_handler3; break;
+
+		case 4: handler = io_timer_handler4; break;
+
+		case 5: handler = io_timer_handler5; break;
+
+		case 6: handler = io_timer_handler6; break;
+
+		case 7: handler = io_timer_handler7; break;
+
+		default:
+			handler = NULL;
+			rv = -EINVAL;
+			break;
+		}
+
+		if (handler) {
+			irq_attach(io_timers[timer].vectorno, handler, NULL);
+			up_enable_irq(io_timers[timer].vectorno);
+		}
 
 		px4_leave_critical_section(flags);
 	}

platforms/nuttx/src/px4/nxp/s32k1xx/include/px4_arch/io_timer.h

@@ -82,11 +82,18 @@ typedef struct io_timers_t {
 	uint32_t	clock_register;      /* SIM_SCGCn */
 	uint32_t	clock_bit;           /* SIM_SCGCn bit pos */
 	uint32_t	vectorno;            /* IRQ number */
-	uint32_t    first_channel_index; /* 0 based index in timer_io_channels */
-	uint32_t    last_channel_index;  /* 0 based index in timer_io_channels */
-	xcpt_t      handler;
 } io_timers_t;
 
+typedef struct io_timers_channel_mapping_element_t {
+	uint32_t first_channel_index;
+	uint32_t channel_count;
+} io_timers_channel_mapping_element_t;
+
+/* mapping for each io_timers to timer_io_channels */
+typedef struct io_timers_channel_mapping_t {
+	io_timers_channel_mapping_element_t element[MAX_IO_TIMERS];
+} io_timers_channel_mapping_t;
+
 /* array of channels in logical order */
 typedef struct timer_io_channels_t {
 	uint32_t	gpio_out;            /* The timer channel GPIO for PWM */
@@ -104,16 +111,13 @@ typedef void (*channel_handler_t)(void *context, const io_timers_t *timer, uint3
 
 /* supplied by board-specific code */
 __EXPORT extern const io_timers_t io_timers[MAX_IO_TIMERS];
+__EXPORT extern const io_timers_channel_mapping_t io_timers_channel_mapping;
 __EXPORT extern const timer_io_channels_t timer_io_channels[MAX_TIMER_IO_CHANNELS];
 
 __EXPORT extern const io_timers_t led_pwm_timers[MAX_LED_TIMERS];
 __EXPORT extern const timer_io_channels_t led_pwm_channels[MAX_TIMER_LED_CHANNELS];
 
 __EXPORT extern io_timer_channel_allocation_t allocations[IOTimerChanModeSize];
-__EXPORT int io_timer_handler0(int irq, void *context, void *arg);
-__EXPORT int io_timer_handler1(int irq, void *context, void *arg);
-__EXPORT int io_timer_handler2(int irq, void *context, void *arg);
-__EXPORT int io_timer_handler3(int irq, void *context, void *arg);
 
 __EXPORT int io_timer_channel_init(unsigned channel, io_timer_channel_mode_t mode,
 				   channel_handler_t channel_handler, void *context);
@@ -133,5 +137,17 @@ __EXPORT int io_timer_free_channel(unsigned channel);
 __EXPORT int io_timer_get_channel_mode(unsigned channel);
 __EXPORT int io_timer_get_mode_channels(io_timer_channel_mode_t mode);
 __EXPORT extern void io_timer_trigger(void);
+/**
+ * Returns the pin configuration for a specific channel, to be used as GPIO output.
+ * 0 is returned if the channel is not valid.
+ */
+__EXPORT uint32_t io_timer_channel_get_gpio_output(unsigned channel);
+/**
+ * Returns the pin configuration for a specific channel, to be used as PWM input.
+ * 0 is returned if the channel is not valid.
+ */
+__EXPORT uint32_t io_timer_channel_get_as_pwm_input(unsigned channel);
+
 
 __END_DECLS
+

platforms/nuttx/src/px4/nxp/s32k1xx/io_pins/io_timer.c

@@ -31,8 +31,8 @@
  *
  ****************************************************************************/
 
-/*
- * @file drv_io_timer.c
+/**
+ * @file io_timer.c
  *
  * Servo driver supporting PWM servos connected to Kinetis FTM timer blocks.
  */
@@ -62,6 +62,16 @@
 #include "hardware/kinetis_sim.h"
 #include "hardware/kinetis_ftm.h"
 
+
+static int io_timer_handler0(int irq, void *context, void *arg);
+static int io_timer_handler1(int irq, void *context, void *arg);
+static int io_timer_handler2(int irq, void *context, void *arg);
+static int io_timer_handler3(int irq, void *context, void *arg);
+static int io_timer_handler4(int irq, void *context, void *arg);
+static int io_timer_handler5(int irq, void *context, void *arg);
+static int io_timer_handler6(int irq, void *context, void *arg);
+static int io_timer_handler7(int irq, void *context, void *arg);
+
 /* The FTM pre-scalers are limited to Divide by 2^n where n={1-7}
  * Therefore we use Y1 at 16 Mhz to drive FTM_CLKIN0 (PCT12)
  * and use this at a 16Mhz clock for FTM0, FTM2 and FTM3.
@@ -184,7 +194,10 @@ static int io_timer_handler(uint16_t timer_index)
 
 	/* Iterate over the timer_io_channels table */
 
-	for (unsigned chan_index = tmr->first_channel_index; chan_index <= tmr->last_channel_index; chan_index++) {
+	uint32_t first_channel_index = io_timers_channel_mapping.element[timer_index].first_channel_index;
+	uint32_t last_channel_index = first_channel_index + io_timers_channel_mapping.element[timer_index].channel_count;
+
+	for (unsigned chan_index = first_channel_index; chan_index < last_channel_index; chan_index++) {
 
 		uint16_t chan = 1 << chan_index;
 
@@ -216,26 +229,39 @@ static int io_timer_handler(uint16_t timer_index)
 
 int io_timer_handler0(int irq, void *context, void *arg)
 {
-
 	return io_timer_handler(0);
 }
 
 int io_timer_handler1(int irq, void *context, void *arg)
 {
 	return io_timer_handler(1);
-
 }
 
 int io_timer_handler2(int irq, void *context, void *arg)
 {
 	return io_timer_handler(2);
-
 }
 
 int io_timer_handler3(int irq, void *context, void *arg)
 {
 	return io_timer_handler(3);
+}
 
+int io_timer_handler4(int irq, void *context, void *arg)
+{
+	return io_timer_handler(4);
+}
+int io_timer_handler5(int irq, void *context, void *arg)
+{
+	return io_timer_handler(5);
+}
+int io_timer_handler6(int irq, void *context, void *arg)
+{
+	return io_timer_handler(6);
+}
+int io_timer_handler7(int irq, void *context, void *arg)
+{
+	return io_timer_handler(7);
 }
 
 static inline int validate_timer_index(unsigned timer)
@@ -269,17 +295,6 @@ static inline int channels_timer(unsigned channel)
 	return timer_io_channels[channel].timer_index;
 }
 
-static inline int get_timers_firstchannels(unsigned timer)
-{
-	int channel = -1;
-
-	if (validate_timer_index(timer) == 0) {
-		channel = timer_io_channels[io_timers[timer].first_channel_index].timer_channel;
-	}
-
-	return channel;
-}
-
 static uint32_t get_timer_channels(unsigned timer)
 {
 	uint32_t channels = 0;
@@ -290,11 +305,13 @@ static uint32_t get_timer_channels(unsigned timer)
 
 	} else {
 		if (channels_cache[timer] == 0) {
-			const io_timers_t *tmr = &io_timers[timer];
 
 			/* Gather the channel bits that belong to the timer */
 
-			for (unsigned chan_index = tmr->first_channel_index; chan_index <= tmr->last_channel_index; chan_index++) {
+			uint32_t first_channel_index = io_timers_channel_mapping.element[timer].first_channel_index;
+			uint32_t last_channel_index = first_channel_index + io_timers_channel_mapping.element[timer].channel_count;
+
+			for (unsigned chan_index = first_channel_index; chan_index < last_channel_index; chan_index++) {
 				channels |= 1 << chan_index;
 			}
 
@@ -345,6 +362,25 @@ int io_timer_validate_channel_index(unsigned channel)
 	return rv;
 }
 
+uint32_t io_timer_channel_get_gpio_output(unsigned channel)
+{
+	if (io_timer_validate_channel_index(channel) != 0) {
+		return 0;
+	}
+
+	return (timer_io_channels[channel].gpio_out & ~(_PIN_MODE_MASK | _PIN_OPTIONS_MASK)) | GPIO_HIGHDRIVE;
+}
+
+uint32_t io_timer_channel_get_as_pwm_input(unsigned channel)
+{
+	if (io_timer_validate_channel_index(channel) != 0) {
+		return 0;
+	}
+
+	return timer_io_channels[channel].gpio_in;
+}
+
+
 int io_timer_get_mode_channels(io_timer_channel_mode_t mode)
 {
 	if (mode < IOTimerChanModeSize) {
@@ -577,10 +613,35 @@ int io_timer_init_timer(unsigned timer)
 		 * Note that the timer is left disabled with IRQ subs installed
 		 * and active but DEIR bits are not set.
 		 */
+		xcpt_t handler;
 
-		irq_attach(io_timers[timer].vectorno, io_timers[timer].handler, NULL);
+		switch (timer) {
+		case 0: handler = io_timer_handler0; break;
 
-		up_enable_irq(io_timers[timer].vectorno);
+		case 1: handler = io_timer_handler1; break;
+
+		case 2: handler = io_timer_handler2; break;
+
+		case 3: handler = io_timer_handler3; break;
+
+		case 4: handler = io_timer_handler4; break;
+
+		case 5: handler = io_timer_handler5; break;
+
+		case 6: handler = io_timer_handler6; break;
+
+		case 7: handler = io_timer_handler7; break;
+
+		default:
+			handler = NULL;
+			rv = -EINVAL;
+			break;
+		}
+
+		if (handler) {
+			irq_attach(io_timers[timer].vectorno, handler, NULL);
+			up_enable_irq(io_timers[timer].vectorno);
+		}
 
 		px4_leave_critical_section(flags);
 	}

platforms/nuttx/src/px4/stm/stm32_common/dshot/dshot.c

@@ -108,7 +108,7 @@ int up_dshot_init(uint32_t channel_mask, unsigned dshot_pwm_freq)
 #pragma GCC diagnostic ignored "-Wcast-align"
 		dshot_burst_buffer[timer] = (uint32_t *)&dshot_burst_buffer_array[buffer_offset];
 #pragma GCC diagnostic pop
-		buffer_offset += DSHOT_BURST_BUFFER_SIZE(io_timers[timer].dshot.channels_number);
+		buffer_offset += DSHOT_BURST_BUFFER_SIZE(io_timers_channel_mapping.element[timer].channel_count);
 
 		if (buffer_offset > sizeof(dshot_burst_buffer_array)) {
 			return -EINVAL; // something is wrong with the board configuration or some other logic
@@ -143,8 +143,9 @@ int up_dshot_init(uint32_t channel_mask, unsigned dshot_pwm_freq)
 	for (uint8_t timer_index = 0; (timer_index < DSHOT_TIMERS) && (OK == ret_val); timer_index++) {
 
 		if (true == dshot_handler[timer_index].init) {
-			dshot_handler[timer_index].dma_size = io_timers[timer_index].dshot.channels_number * ONE_MOTOR_BUFF_SIZE;
-			io_timer_set_dshot_mode(timer_index, dshot_pwm_freq, io_timers[timer_index].dshot.channels_number);
+			dshot_handler[timer_index].dma_size = io_timers_channel_mapping.element[timer_index].channel_count *
+							      ONE_MOTOR_BUFF_SIZE;
+			io_timer_set_dshot_mode(timer_index, dshot_pwm_freq, io_timers_channel_mapping.element[timer_index].channel_count);
 
 			dshot_handler[timer_index].dma_handle = stm32_dmachannel(io_timers[timer_index].dshot.dmamap);
 
@@ -165,7 +166,7 @@ void up_dshot_trigger(void)
 
 		if (true == dshot_handler[timer].init) {
 
-			uint8_t motors_number = io_timers[timer].dshot.channels_number;
+			uint8_t motors_number = io_timers_channel_mapping.element[timer].channel_count;
 			dshot_dmar_data_prepare(timer, first_motor, motors_number);
 
 			// Flush cache so DMA sees the data

platforms/nuttx/src/px4/stm/stm32_common/include/px4_arch/dshot.h

@@ -59,6 +59,4 @@
 typedef struct dshot_conf_t {
 	uint32_t			dma_base;
 	uint32_t			dmamap;
-	uint32_t			start_ccr_register;
-	uint8_t				channels_number;  ///< number of channels/outputs (<=MAX_NUM_CHANNELS_PER_TIMER)
 } dshot_conf_t;

platforms/nuttx/src/px4/stm/stm32_common/include/px4_arch/io_timer.h

@@ -89,12 +89,19 @@ typedef struct io_timers_t {
 	uint32_t		clock_bit;
 	uint32_t		clock_freq;
 	uint32_t		vectorno;
-	uint32_t		first_channel_index;
-	uint32_t		last_channel_index;
-	xcpt_t			handler;
 	dshot_conf_t	dshot;
 } io_timers_t;
 
+typedef struct io_timers_channel_mapping_element_t {
+	uint32_t first_channel_index;
+	uint32_t channel_count;
+} io_timers_channel_mapping_element_t;
+
+/* mapping for each io_timers to timer_io_channels */
+typedef struct io_timers_channel_mapping_t {
+	io_timers_channel_mapping_element_t element[MAX_IO_TIMERS];
+} io_timers_channel_mapping_t;
+
 /* array of channels in logical order */
 typedef struct timer_io_channels_t {
 	uint32_t	gpio_out;
@@ -105,7 +112,6 @@ typedef struct timer_io_channels_t {
 	uint8_t		ccr_offset;
 } timer_io_channels_t;
 
-
 typedef void (*channel_handler_t)(void *context, const io_timers_t *timer, uint32_t chan_index,
 				  const timer_io_channels_t *chan,
 				  hrt_abstime isrs_time, uint16_t isrs_rcnt);
@@ -113,17 +119,13 @@ typedef void (*channel_handler_t)(void *context, const io_timers_t *timer, uint3
 
 /* supplied by board-specific code */
 __EXPORT extern const io_timers_t io_timers[MAX_IO_TIMERS];
+__EXPORT extern const io_timers_channel_mapping_t io_timers_channel_mapping;
 __EXPORT extern const timer_io_channels_t timer_io_channels[MAX_TIMER_IO_CHANNELS];
 
 __EXPORT extern const io_timers_t led_pwm_timers[MAX_LED_TIMERS];
 __EXPORT extern const timer_io_channels_t led_pwm_channels[MAX_TIMER_LED_CHANNELS];
 
 __EXPORT extern io_timer_channel_allocation_t allocations[IOTimerChanModeSize];
-__EXPORT int io_timer_handler0(int irq, void *context, void *arg);
-__EXPORT int io_timer_handler1(int irq, void *context, void *arg);
-__EXPORT int io_timer_handler2(int irq, void *context, void *arg);
-__EXPORT int io_timer_handler3(int irq, void *context, void *arg);
-__EXPORT int io_timer_handler4(int irq, void *context, void *arg);
 
 __EXPORT int io_timer_channel_init(unsigned channel, io_timer_channel_mode_t mode,
 				   channel_handler_t channel_handler, void *context);

platforms/nuttx/src/px4/stm/stm32_common/io_pins/io_timer.c

@@ -59,6 +59,16 @@
 #include <stm32_gpio.h>
 #include <stm32_tim.h>
 
+
+static int io_timer_handler0(int irq, void *context, void *arg);
+static int io_timer_handler1(int irq, void *context, void *arg);
+static int io_timer_handler2(int irq, void *context, void *arg);
+static int io_timer_handler3(int irq, void *context, void *arg);
+static int io_timer_handler4(int irq, void *context, void *arg);
+static int io_timer_handler5(int irq, void *context, void *arg);
+static int io_timer_handler6(int irq, void *context, void *arg);
+static int io_timer_handler7(int irq, void *context, void *arg);
+
 #if defined(HAVE_GTIM_CCXNP)
 #define HW_GTIM_CCER_CC1NP GTIM_CCER_CC1NP
 #else
@@ -182,7 +192,10 @@ static int io_timer_handler(uint16_t timer_index)
 
 	/* Iterate over the timer_io_channels table */
 
-	for (unsigned chan_index = tmr->first_channel_index; chan_index <= tmr->last_channel_index; chan_index++) {
+	uint32_t first_channel_index = io_timers_channel_mapping.element[timer_index].first_channel_index;
+	uint32_t last_channel_index = first_channel_index + io_timers_channel_mapping.element[timer_index].channel_count;
+
+	for (unsigned chan_index = first_channel_index; chan_index < last_channel_index; chan_index++) {
 
 		uint16_t masks = timer_io_channels[chan_index].masks;
 
@@ -222,32 +235,42 @@ static int io_timer_handler(uint16_t timer_index)
 
 int io_timer_handler0(int irq, void *context, void *arg)
 {
-
 	return io_timer_handler(0);
 }
 
 int io_timer_handler1(int irq, void *context, void *arg)
 {
 	return io_timer_handler(1);
-
 }
 
 int io_timer_handler2(int irq, void *context, void *arg)
 {
 	return io_timer_handler(2);
-
 }
 
 int io_timer_handler3(int irq, void *context, void *arg)
 {
 	return io_timer_handler(3);
-
 }
 
 int io_timer_handler4(int irq, void *context, void *arg)
 {
 	return io_timer_handler(4);
+}
 
+int io_timer_handler5(int irq, void *context, void *arg)
+{
+	return io_timer_handler(5);
+}
+
+int io_timer_handler6(int irq, void *context, void *arg)
+{
+	return io_timer_handler(6);
+}
+
+int io_timer_handler7(int irq, void *context, void *arg)
+{
+	return io_timer_handler(7);
 }
 
 static inline int validate_timer_index(unsigned timer)
@@ -281,17 +304,6 @@ static inline int channels_timer(unsigned channel)
 	return timer_io_channels[channel].timer_index;
 }
 
-static inline int get_timers_firstchannels(unsigned timer)
-{
-	int channel = -1;
-
-	if (validate_timer_index(timer) == 0) {
-		channel = timer_io_channels[io_timers[timer].first_channel_index].timer_channel;
-	}
-
-	return channel;
-}
-
 static uint32_t get_timer_channels(unsigned timer)
 {
 	uint32_t channels = 0;
@@ -302,11 +314,12 @@ static uint32_t get_timer_channels(unsigned timer)
 
 	} else {
 		if (channels_cache[timer] == 0) {
-			const io_timers_t *tmr = &io_timers[timer];
-
 			/* Gather the channel bits that belong to the timer */
 
-			for (unsigned chan_index = tmr->first_channel_index; chan_index <= tmr->last_channel_index; chan_index++) {
+			uint32_t first_channel_index = io_timers_channel_mapping.element[timer].first_channel_index;
+			uint32_t last_channel_index = first_channel_index + io_timers_channel_mapping.element[timer].channel_count;
+
+			for (unsigned chan_index = first_channel_index; chan_index < last_channel_index; chan_index++) {
 				channels |= 1 << chan_index;
 			}
 
@@ -527,7 +540,31 @@ int io_timer_set_dshot_mode(uint8_t timer, unsigned dshot_pwm_freq, uint8_t dma_
 		rARR(timer)  = DSHOT_MOTOR_PWM_BIT_WIDTH;
 		rPSC(timer)  = ((int)(io_timers[timer].clock_freq / dshot_pwm_freq) / DSHOT_MOTOR_PWM_BIT_WIDTH) - 1;
 		rEGR(timer)  = ATIM_EGR_UG;
-		rDCR(timer)  = (io_timers[timer].dshot.start_ccr_register | tim_dma_burst_length);
+
+		// find the lowest channel index for the timer (they are not necesarily in ascending order)
+		unsigned lowest_timer_channel = 4;
+		uint32_t first_channel_index = io_timers_channel_mapping.element[timer].first_channel_index;
+		uint32_t last_channel_index = first_channel_index + io_timers_channel_mapping.element[timer].channel_count;
+
+		for (unsigned chan_index = first_channel_index; chan_index < last_channel_index; chan_index++) {
+			if (timer_io_channels[chan_index].timer_channel < lowest_timer_channel) {
+				lowest_timer_channel = timer_io_channels[chan_index].timer_channel;
+			}
+		}
+
+		uint32_t start_ccr_register = 0;
+
+		switch (lowest_timer_channel) {
+		case 1: start_ccr_register = TIM_DMABASE_CCR1; break;
+
+		case 2: start_ccr_register = TIM_DMABASE_CCR2; break;
+
+		case 3: start_ccr_register = TIM_DMABASE_CCR3; break;
+
+		case 4: start_ccr_register = TIM_DMABASE_CCR4; break;
+		}
+
+		rDCR(timer)  = start_ccr_register | tim_dma_burst_length;
 	}
 
 	return ret_val;
@@ -621,10 +658,35 @@ int io_timer_init_timer(unsigned timer)
 		 * Note that the timer is left disabled with IRQ subs installed
 		 * and active but DEIR bits are not set.
 		 */
+		xcpt_t handler;
 
-		irq_attach(io_timers[timer].vectorno, io_timers[timer].handler, NULL);
+		switch (timer) {
+		case 0: handler = io_timer_handler0; break;
 
-		up_enable_irq(io_timers[timer].vectorno);
+		case 1: handler = io_timer_handler1; break;
+
+		case 2: handler = io_timer_handler2; break;
+
+		case 3: handler = io_timer_handler3; break;
+
+		case 4: handler = io_timer_handler4; break;
+
+		case 5: handler = io_timer_handler5; break;
+
+		case 6: handler = io_timer_handler6; break;
+
+		case 7: handler = io_timer_handler7; break;
+
+		default:
+			handler = NULL;
+			rv = -EINVAL;
+			break;
+		}
+
+		if (handler) {
+			irq_attach(io_timers[timer].vectorno, handler, NULL);
+			up_enable_irq(io_timers[timer].vectorno);
+		}
 
 		px4_leave_critical_section(flags);
 	}