diff options
Diffstat (limited to 'drivers/net/can/flexcan/dev.c')
| -rw-r--r-- | drivers/net/can/flexcan/dev.c | 112 |
1 files changed, 110 insertions, 2 deletions
diff --git a/drivers/net/can/flexcan/dev.c b/drivers/net/can/flexcan/dev.c index 389f85d75709..404877c33eab 100644 --- a/drivers/net/can/flexcan/dev.c +++ b/drivers/net/can/flexcan/dev.c @@ -35,6 +35,74 @@ #endif #include "flexcan.h" +#define DEFAULT_BITRATE 500000 +#define TIME_SEGMENT_MIN 8 +#define TIME_SEGMENT_MAX 25 +#define TIME_SEGMENT_MID ((TIME_SEGMENT_MIN + TIME_SEGMENT_MAX)/2) + +struct time_segment { + char propseg; + char pseg1; + char pseg2; +}; + +struct time_segment time_segments[] = { + { /* total 8 timequanta */ + 1, 2, 1 + }, + { /* total 9 timequanta */ + 1, 2, 2 + }, + { /* total 10 timequanta */ + 2, 2, 2 + }, + { /* total 11 timequanta */ + 2, 2, 3 + }, + { /* total 12 timequanta */ + 2, 3, 3 + }, + { /* total 13 timequanta */ + 3, 3, 3 + }, + { /* total 14 timequanta */ + 3, 3, 4 + }, + { /* total 15 timequanta */ + 3, 4, 4 + }, + { /* total 16 timequanta */ + 4, 4, 4 + }, + { /* total 17 timequanta */ + 4, 4, 5 + }, + { /* total 18 timequanta */ + 4, 5, 5 + }, + { /* total 19 timequanta */ + 5, 5, 5 + }, + { /* total 20 timequanta */ + 5, 5, 6 + }, + { /* total 21 timequanta */ + 5, 6, 6 + }, + { /* total 22 timequanta */ + 6, 6, 6 + }, + { /* total 23 timequanta */ + 6, 6, 7 + }, + { /* total 24 timequanta */ + 6, 7, 7 + }, + { /* total 25 timequanta */ + 7, 7, 7 + }, +}; + enum { FLEXCAN_ATTR_STATE = 0, FLEXCAN_ATTR_BITRATE, @@ -138,6 +206,45 @@ static void flexcan_set_bitrate(struct flexcan_device *flexcan, int bitrate) * based on the bitrate to get the timing of * presdiv, pseg1, pseg2, propseg */ + int i, rate, div; + bool found = false; + struct time_segment *segment; + rate = clk_get_rate(flexcan->clk); + + if (!bitrate) + bitrate = DEFAULT_BITRATE; + + if (rate % bitrate == 0) { + div = rate / bitrate; + for (i = TIME_SEGMENT_MID; i <= TIME_SEGMENT_MAX; i++) { + if (div % i == 0) { + found = true; + break; + } + } + if (!found) { + for (i = TIME_SEGMENT_MID - 1; + i >= TIME_SEGMENT_MIN; i--) { + if (div % i == 0) { + found = true; + break; + } + } + + } + } + + if (found) { + segment = &time_segments[i - TIME_SEGMENT_MIN]; + flexcan->br_presdiv = div/i - 1; + flexcan->br_propseg = segment->propseg; + flexcan->br_pseg1 = segment->pseg1; + flexcan->br_pseg2 = segment->pseg2; + flexcan->bitrate = bitrate; + } else { + pr_info("The bitrate %d can't supported with clock \ + rate of %d \n", bitrate, rate); + } } static void flexcan_update_bitrate(struct flexcan_device *flexcan) @@ -201,7 +308,7 @@ static int flexcan_dump_xmit_mb(struct flexcan_device *flexcan, char *buf) ret += sprintf(buf + ret, "mb[%d]::CS:0x%x ID:0x%x DATA[1~2]:0x%02x,0x%02x\n", - i, flexcan->hwmb[i].mb_cs.data, + i, flexcan->hwmb[i].mb_cs, flexcan->hwmb[i].mb_id, flexcan->hwmb[i].mb_data[1], flexcan->hwmb[i].mb_data[2]); return ret; @@ -214,7 +321,7 @@ static int flexcan_dump_rx_mb(struct flexcan_device *flexcan, char *buf) ret += sprintf(buf + ret, "mb[%d]::CS:0x%x ID:0x%x DATA[1~2]:0x%02x,0x%02x\n", - i, flexcan->hwmb[i].mb_cs.data, + i, flexcan->hwmb[i].mb_cs, flexcan->hwmb[i].mb_id, flexcan->hwmb[i].mb_data[1], flexcan->hwmb[i].mb_data[2]); return ret; @@ -575,6 +682,7 @@ struct net_device *flexcan_device_alloc(struct platform_device *pdev, return NULL; } flexcan_device_default(flexcan); + flexcan_set_bitrate(flexcan, flexcan->bitrate); flexcan_update_bitrate(flexcan); num = ARRAY_SIZE(flexcan_dev_attr); |