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Implement daisy chaining for BD8LB600FS #65982

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merged 2 commits into from
Jan 25, 2024
Merged

Implement daisy chaining for BD8LB600FS #65982

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3371c79
drivers: gpio: implement daisy chaining for BD8LB600FS
benediktibk Nov 30, 2023
da77fec
drivers: gpio: add missing check if GPIO is ready for BD8LB600FS
benediktibk Dec 12, 2023
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86 changes: 63 additions & 23 deletions drivers/gpio/gpio_bd8lb600fs.c
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Expand Up @@ -30,40 +30,61 @@ struct bd8lb600fs_config {

struct spi_dt_spec bus;
const struct gpio_dt_spec gpio_reset;
int gpios_count;
};

struct bd8lb600fs_drv_data {
/* gpio_driver_data needs to be first */
struct gpio_driver_data data;
uint8_t state; /* each bit is one output channel, bit 0 = channel 1, ... */
uint8_t configured; /* each bit defines if the output channel is configured, see state */
uint32_t state; /* each bit is one output channel, bit 0 = channel 1, ... */
uint32_t configured; /* each bit defines if the output channel is configured, see state */
struct k_mutex lock;
int instance_count_actual;
int gpios_count_actual;
};

static int write_state(const struct bd8lb600fs_config *config, uint8_t state)
static int write_state(const struct device *dev, uint32_t state)
{
LOG_DBG("writing state 0x%02X to BD8LB600FS", state);
const struct bd8lb600fs_config *config = dev->config;
struct bd8lb600fs_drv_data *drv_data = dev->data;

LOG_DBG("%s: writing state 0x%08X to BD8LB600FS", dev->name, state);

uint16_t state_converted = 0;
uint8_t buffer_tx[2];
const struct spi_buf tx_buf[] = {{
uint8_t buffer_tx[8];
const struct spi_buf tx_buf = {
.buf = buffer_tx,
.len = ARRAY_SIZE(buffer_tx),
}};
.len = drv_data->instance_count_actual * sizeof(state_converted),
};
const struct spi_buf_set tx = {
.buffers = tx_buf,
.count = ARRAY_SIZE(tx_buf),
.buffers = &tx_buf,
.count = 1,
};

for (size_t i = 0; i < 8; ++i) {
if ((state & BIT(i)) == 0) {
state_converted |= OUTPUT_OFF_WITH_OPEN_LOAD_DETECTION << (i * 2);
} else {
state_converted |= OUTPUT_ON << (i * 2);
memset(buffer_tx, 0x00, sizeof(buffer_tx));

for (size_t j = 0; j < drv_data->instance_count_actual; ++j) {
int instance_position = (drv_data->instance_count_actual - j - 1) * 2;

state_converted = 0;

for (size_t i = 0; i < 8; ++i) {
if ((state & BIT(i + j*8)) == 0) {
state_converted |= OUTPUT_OFF_WITH_OPEN_LOAD_DETECTION << (i * 2);
} else {
state_converted |= OUTPUT_ON << (i * 2);
}
}

LOG_DBG("%s: configuration for instance %i: %04X (position %i)",
dev->name,
j,
state_converted,
instance_position);
sys_put_be16(state_converted, buffer_tx + instance_position);
}

sys_put_be16(state_converted, buffer_tx);
LOG_HEXDUMP_DBG(buffer_tx, ARRAY_SIZE(buffer_tx), "configuration written out");

int result = spi_write_dt(&config->bus, &tx);

Expand All @@ -77,15 +98,14 @@ static int write_state(const struct bd8lb600fs_config *config, uint8_t state)

static int bd8lb600fs_pin_configure(const struct device *dev, gpio_pin_t pin, gpio_flags_t flags)
{
const struct bd8lb600fs_config *config = dev->config;
struct bd8lb600fs_drv_data *drv_data = dev->data;

/* cannot execute a bus operation in an ISR context */
if (k_is_in_isr()) {
return -EWOULDBLOCK;
}

if (pin > 7) {
if (pin >= drv_data->gpios_count_actual) {
LOG_ERR("invalid pin number %i", pin);
return -EINVAL;
}
Expand Down Expand Up @@ -130,7 +150,7 @@ static int bd8lb600fs_pin_configure(const struct device *dev, gpio_pin_t pin, gp

WRITE_BIT(drv_data->configured, pin, 1);

int result = write_state(config, drv_data->state);
int result = write_state(dev, drv_data->state);

k_mutex_unlock(&drv_data->lock);

Expand All @@ -145,7 +165,6 @@ static int bd8lb600fs_port_get_raw(const struct device *dev, uint32_t *value)

static int bd8lb600fs_port_set_masked_raw(const struct device *dev, uint32_t mask, uint32_t value)
{
const struct bd8lb600fs_config *config = dev->config;
struct bd8lb600fs_drv_data *drv_data = dev->data;

/* cannot execute a bus operation in an ISR context */
Expand All @@ -156,7 +175,7 @@ static int bd8lb600fs_port_set_masked_raw(const struct device *dev, uint32_t mas
k_mutex_lock(&drv_data->lock, K_FOREVER);
drv_data->state = (drv_data->state & ~mask) | (mask & value);

int result = write_state(config, drv_data->state);
int result = write_state(dev, drv_data->state);

k_mutex_unlock(&drv_data->lock);

Expand All @@ -175,7 +194,6 @@ static int bd8lb600fs_port_clear_bits_raw(const struct device *dev, uint32_t mas

static int bd8lb600fs_port_toggle_bits(const struct device *dev, uint32_t mask)
{
const struct bd8lb600fs_config *config = dev->config;
struct bd8lb600fs_drv_data *drv_data = dev->data;

/* cannot execute a bus operation in an ISR context */
Expand All @@ -186,7 +204,7 @@ static int bd8lb600fs_port_toggle_bits(const struct device *dev, uint32_t mask)
k_mutex_lock(&drv_data->lock, K_FOREVER);
drv_data->state ^= mask;

int result = write_state(config, drv_data->state);
int result = write_state(dev, drv_data->state);

k_mutex_unlock(&drv_data->lock);

Expand All @@ -212,13 +230,34 @@ static int bd8lb600fs_init(const struct device *dev)
return -ENODEV;
}

if (!gpio_is_ready_dt(&config->gpio_reset)) {
LOG_ERR("%s: reset GPIO is not ready", dev->name);
return -ENODEV;
}

int result = k_mutex_init(&drv_data->lock);

if (result != 0) {
LOG_ERR("unable to initialize mutex");
return result;
}

drv_data->instance_count_actual = config->gpios_count / 8;

if (config->gpios_count % 8 != 0) {
LOG_ERR("%s: number of GPIOs %i is not a multiple of 8",
dev->name, config->gpios_count);
return -EINVAL;
}

if (drv_data->instance_count_actual > 4) {
LOG_ERR("%s: only a maximum of 4 devices are supported for the daisy chaining",
dev->name);
return -EINVAL;
}

drv_data->gpios_count_actual = drv_data->instance_count_actual * 8;

result = gpio_pin_configure_dt(&config->gpio_reset, GPIO_OUTPUT_ACTIVE);

if (result != 0) {
Expand All @@ -242,6 +281,7 @@ static int bd8lb600fs_init(const struct device *dev)
.bus = SPI_DT_SPEC_INST_GET( \
inst, SPI_OP_MODE_MASTER | SPI_MODE_CPHA | SPI_WORD_SET(8), 0), \
.gpio_reset = GPIO_DT_SPEC_GET_BY_IDX(DT_DRV_INST(inst), reset_gpios, 0), \
.gpios_count = DT_INST_PROP(inst, ngpios), \
}; \
\
static struct bd8lb600fs_drv_data bd8lb600fs_##inst##_drvdata = { \
Expand Down
10 changes: 7 additions & 3 deletions dts/bindings/gpio/rohm,bd8lb600fs.yaml
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Expand Up @@ -6,6 +6,8 @@

description: |
This is a representation of the Rohm BD8LB600FS SPI Gpio Expander.
Multiple instances may be daisy chained, which can be configured
via the number of supported GPIOs.

compatible: "rohm,bd8lb600fs"

Expand All @@ -18,13 +20,15 @@ properties:
ngpios:
type: int
required: true
const: 8
henrikbrixandersen marked this conversation as resolved.
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description: Number of gpios supported
description: |
Number of pins for the expander. This must be a multiple of 8.
The number of pins also defines how many devices are daisy chained.
Set to 8 for one instance without daisy chaining.

reset-gpios:
type: phandle-array
required: true
description: "GPIO for reset"
description: GPIO for reset

gpio-cells:
- pin
Expand Down