kingst-la2016: reword buffer size in FPGA register access

Phrase communication buffer sizes in terms of FPGA register width,
instead of totalling the sizes of different bitfield width. Comment
where buffers are shared among different accesses, for awareness
during maintenance.

Introduce an "unknown register at offset 0x30" such that REG_TRIGGER
access can follow the pattern of determining the FPGA register's width.

diff --git a/src/hardware/kingst-la2016/protocol.c b/src/hardware/kingst-la2016/protocol.c
index 976bc3e2dd612bfe818812daaccd2d702fd7b955..c01bcc33a93d95d28f662db4bdf176dc36854770 100644 (file)
--- a/src/hardware/kingst-la2016/protocol.c
+++ b/src/hardware/kingst-la2016/protocol.c
@@ -80,7 +80,8 @@ static const struct kingst_model models[] = {
 #define REG_CAPT_MODE  0x03    /* Write 0x00 capture to SDRAM, 0x01 streaming. */
 #define REG_BULK       0x08    /* Write start addr, byte count to download samples. */
 #define REG_SAMPLING   0x10    /* Write capture config, read capture SDRAM location. */
-#define REG_TRIGGER    0x20    /* write level and edge trigger config. */
+#define REG_TRIGGER    0x20    /* Write level and edge trigger config. */
+#define REG_UNKNOWN_30 0x30
 #define REG_THRESHOLD  0x68    /* Write PWM config to setup input threshold DAC. */
 #define REG_PWM1       0x70    /* Write config for user PWM1. */
 #define REG_PWM2       0x78    /* Write config for user PWM2. */
@@ -168,11 +169,11 @@ static int ctrl_out(const struct sr_dev_inst *sdi,
 static int check_fpga_bitstream(const struct sr_dev_inst *sdi)
 {
        uint8_t init_rsp;
+       uint8_t buff[REG_PWM_EN - REG_RUN]; /* Larger of REG_RUN, REG_PWM_EN. */
        int ret;
        uint16_t run_state;
        uint8_t pwm_en;
        size_t read_len;
-       uint8_t buff[sizeof(run_state)];
        const uint8_t *rdptr;
 
        sr_dbg("Checking operation of the FPGA bitstream.");
@@ -337,7 +338,7 @@ static int set_threshold_voltage(const struct sr_dev_inst *sdi, float voltage)
 {
        int ret;
        uint16_t duty_R79, duty_R56;
-       uint8_t buf[2 * sizeof(uint16_t)];
+       uint8_t buf[REG_PWM1 - REG_THRESHOLD]; /* Width of REG_THRESHOLD. */
        uint8_t *wrptr;
 
        /* Clamp threshold setting to valid range for LA2016. */
@@ -526,7 +527,7 @@ static int set_trigger_config(const struct sr_dev_inst *sdi)
        struct sr_trigger_match *match;
        uint16_t ch_mask;
        int ret;
-       uint8_t buf[4 * sizeof(uint32_t)];
+       uint8_t buf[REG_UNKNOWN_30 - REG_TRIGGER]; /* Width of REG_TRIGGER. */
        uint8_t *wrptr;
 
        devc = sdi->priv;
@@ -766,7 +767,7 @@ static uint16_t run_state(const struct sr_dev_inst *sdi)
 
        int ret;
        uint16_t state;
-       uint8_t buff[sizeof(state)];
+       uint8_t buff[REG_PWM_EN - REG_RUN]; /* Width of REG_RUN. */
        const uint8_t *rdptr;
        const char *label;
 
@@ -831,7 +832,7 @@ static int get_capture_info(const struct sr_dev_inst *sdi)
 {
        struct dev_context *devc;
        int ret;
-       uint8_t buf[3 * sizeof(uint32_t)];
+       uint8_t buf[REG_TRIGGER - REG_SAMPLING]; /* Width of REG_SAMPLING. */
        const uint8_t *rdptr;
 
        devc = sdi->priv;
@@ -961,7 +962,7 @@ static int la2016_start_download(const struct sr_dev_inst *sdi,
        struct dev_context *devc;
        struct sr_usb_dev_inst *usb;
        int ret;
-       uint8_t wrbuf[2 * sizeof(uint32_t)];
+       uint8_t wrbuf[REG_SAMPLING - REG_BULK]; /* Width of REG_BULK. */
        uint8_t *wrptr;
        uint32_t to_read;
        uint8_t *buffer;
@@ -1231,7 +1232,7 @@ SR_PRIV int la2016_identify_device(const struct sr_dev_inst *sdi,
        gboolean show_message)
 {
        struct dev_context *devc;
-       uint8_t buf[8];
+       uint8_t buf[8]; /* Larger size of manuf date and device type magic. */
        size_t rdoff, rdlen;
        const uint8_t *rdptr;
        uint8_t date_yy, date_mm;