On 11/20/2012 01:36 PM, Lars-Peter Clausen wrote:
> Some of the newer generation devices from the ADIS16XXX series have more
> registers than what can be supported with the current register addressing
> scheme. These devices implement register paging to support a larger register
> range. Each page is 128 registers large and the currently active page can be
> selected via register 0x00 in each page. This patch implements transparent
> paging inside the common adis library. The register read/write interface stays
> the same and when a register is accessed the library automatically switches to
> the correct page if it is not already selected. The page number is encoded in
> the upper bits of the register number, e.g. register 0x5 of page 1 is 0x85.
>
> Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
added to togreg branch of iio.git
> ---
> drivers/iio/imu/adis.c | 70 +++++++++++++++++++++++++++++++++----------
> drivers/iio/imu/adis_buffer.c | 15 ++++++++++
> include/linux/iio/imu/adis.h | 10 +++++--
> 3 files changed, 77 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c
> index 280a495..c4ea04f 100644
> --- a/drivers/iio/imu/adis.c
> +++ b/drivers/iio/imu/adis.c
> @@ -30,6 +30,7 @@
> int adis_write_reg(struct adis *adis, unsigned int reg,
> unsigned int value, unsigned int size)
> {
> + unsigned int page = reg / ADIS_PAGE_SIZE;
> int ret, i;
> struct spi_message msg;
> struct spi_transfer xfers[] = {
> @@ -56,39 +57,53 @@ int adis_write_reg(struct adis *adis, unsigned int reg,
> .bits_per_word = 8,
> .len = 2,
> .delay_usecs = adis->data->write_delay,
> + }, {
> + .tx_buf = adis->tx + 8,
> + .bits_per_word = 8,
> + .len = 2,
> + .delay_usecs = adis->data->write_delay,
> },
> };
>
> mutex_lock(&adis->txrx_lock);
>
> spi_message_init(&msg);
> +
> + if (adis->current_page != page) {
> + adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
> + adis->tx[1] = page;
> + spi_message_add_tail(&xfers[0], &msg);
> + }
> +
> switch (size) {
> case 4:
> - adis->tx[6] = ADIS_WRITE_REG(reg + 3);
> - adis->tx[7] = (value >> 24) & 0xff;
> - adis->tx[4] = ADIS_WRITE_REG(reg + 2);
> - adis->tx[5] = (value >> 16) & 0xff;
> + adis->tx[8] = ADIS_WRITE_REG(reg + 3);
> + adis->tx[9] = (value >> 24) & 0xff;
> + adis->tx[6] = ADIS_WRITE_REG(reg + 2);
> + adis->tx[7] = (value >> 16) & 0xff;
> case 2:
> - adis->tx[2] = ADIS_WRITE_REG(reg + 1);
> - adis->tx[3] = (value >> 8) & 0xff;
> + adis->tx[4] = ADIS_WRITE_REG(reg + 1);
> + adis->tx[5] = (value >> 8) & 0xff;
> case 1:
> - adis->tx[0] = ADIS_WRITE_REG(reg);
> - adis->tx[1] = value & 0xff;
> + adis->tx[2] = ADIS_WRITE_REG(reg);
> + adis->tx[3] = value & 0xff;
> break;
> default:
> ret = -EINVAL;
> goto out_unlock;
> }
>
> - xfers[size - 1].cs_change = 0;
> + xfers[size].cs_change = 0;
>
> - for (i = 0; i < size; i++)
> + for (i = 1; i <= size; i++)
> spi_message_add_tail(&xfers[i], &msg);
>
> ret = spi_sync(adis->spi, &msg);
> if (ret) {
> dev_err(&adis->spi->dev, "Failed to write register 0x%02X: %d\n",
> reg, ret);
> + } else {
> + adis->current_page = page;
> }
>
> out_unlock:
> @@ -107,6 +122,7 @@ EXPORT_SYMBOL_GPL(adis_write_reg);
> int adis_read_reg(struct adis *adis, unsigned int reg,
> unsigned int *val, unsigned int size)
> {
> + unsigned int page = reg / ADIS_PAGE_SIZE;
> struct spi_message msg;
> int ret;
> struct spi_transfer xfers[] = {
> @@ -115,9 +131,15 @@ int adis_read_reg(struct adis *adis, unsigned int reg,
> .bits_per_word = 8,
> .len = 2,
> .cs_change = 1,
> - .delay_usecs = adis->data->read_delay,
> + .delay_usecs = adis->data->write_delay,
> }, {
> .tx_buf = adis->tx + 2,
> + .bits_per_word = 8,
> + .len = 2,
> + .cs_change = 1,
> + .delay_usecs = adis->data->read_delay,
> + }, {
> + .tx_buf = adis->tx + 4,
> .rx_buf = adis->rx,
> .bits_per_word = 8,
> .len = 2,
> @@ -134,16 +156,22 @@ int adis_read_reg(struct adis *adis, unsigned int reg,
> mutex_lock(&adis->txrx_lock);
> spi_message_init(&msg);
>
> + if (adis->current_page != page) {
> + adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
> + adis->tx[1] = page;
> + spi_message_add_tail(&xfers[0], &msg);
> + }
> +
> switch (size) {
> case 4:
> - adis->tx[0] = ADIS_READ_REG(reg + 2);
> - adis->tx[1] = 0;
> - spi_message_add_tail(&xfers[0], &msg);
> - case 2:
> - adis->tx[2] = ADIS_READ_REG(reg);
> + adis->tx[2] = ADIS_READ_REG(reg + 2);
> adis->tx[3] = 0;
> spi_message_add_tail(&xfers[1], &msg);
> + case 2:
> + adis->tx[4] = ADIS_READ_REG(reg);
> + adis->tx[5] = 0;
> spi_message_add_tail(&xfers[2], &msg);
> + spi_message_add_tail(&xfers[3], &msg);
> break;
> default:
> ret = -EINVAL;
> @@ -155,6 +183,8 @@ int adis_read_reg(struct adis *adis, unsigned int reg,
> dev_err(&adis->spi->dev, "Failed to read register 0x%02X: %d\n",
> reg, ret);
> goto out_unlock;
> + } else {
> + adis->current_page = page;
> }
>
> switch (size) {
> @@ -390,6 +420,14 @@ int adis_init(struct adis *adis, struct iio_dev *indio_dev,
> adis->data = data;
> iio_device_set_drvdata(indio_dev, adis);
>
> + if (data->has_paging) {
> + /* Need to set the page before first read/write */
> + adis->current_page = -1;
> + } else {
> + /* Page will always be 0 */
> + adis->current_page = 0;
> + }
> +
> return adis_enable_irq(adis, false);
> }
> EXPORT_SYMBOL_GPL(adis_init);
> diff --git a/drivers/iio/imu/adis_buffer.c b/drivers/iio/imu/adis_buffer.c
> index 7857133..99d8e0b 100644
> --- a/drivers/iio/imu/adis_buffer.c
> +++ b/drivers/iio/imu/adis_buffer.c
> @@ -83,10 +83,25 @@ static irqreturn_t adis_trigger_handler(int irq, void *p)
> if (!adis->buffer)
> return -ENOMEM;
>
> + if (adis->data->has_paging) {
> + mutex_lock(&adis->txrx_lock);
> + if (adis->current_page != 0) {
> + adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
> + adis->tx[1] = 0;
> + spi_write(adis->spi, adis->tx, 2);
> + }
> + }
> +
> ret = spi_sync(adis->spi, &adis->msg);
> if (ret)
> dev_err(&adis->spi->dev, "Failed to read data: %d", ret);
>
> +
> + if (adis->data->has_paging) {
> + adis->current_page = 0;
> + mutex_unlock(&adis->txrx_lock);
> + }
> +
> /* Guaranteed to be aligned with 8 byte boundary */
> if (indio_dev->scan_timestamp) {
> void *b = adis->buffer + indio_dev->scan_bytes - sizeof(s64);
> diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h
> index 6402a08..e82cd08 100644
> --- a/include/linux/iio/imu/adis.h
> +++ b/include/linux/iio/imu/adis.h
> @@ -14,8 +14,11 @@
> #include <linux/interrupt.h>
> #include <linux/iio/types.h>
>
> -#define ADIS_WRITE_REG(reg) (0x80 | (reg))
> -#define ADIS_READ_REG(reg) (reg)
> +#define ADIS_WRITE_REG(reg) ((0x80 | (reg)))
> +#define ADIS_READ_REG(reg) ((reg) & 0x7f)
> +
> +#define ADIS_PAGE_SIZE 0x80
> +#define ADIS_REG_PAGE_ID 0x00
>
> /**
> * struct adis_data - ADIS chip variant specific data
> @@ -40,6 +43,8 @@ struct adis_data {
>
> const char * const *status_error_msgs;
> unsigned int status_error_mask;
> +
> + bool has_paging;
> };
>
> struct adis {
> @@ -51,6 +56,7 @@ struct adis {
> struct mutex txrx_lock;
> struct spi_message msg;
> struct spi_transfer *xfer;
> + unsigned int current_page;
> void *buffer;
>
> uint8_t tx[10] ____cacheline_aligned;
>
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