diff options
| author | Mathieu Poirier <mathieu.poirier@linaro.org> | 2016-05-03 11:33:57 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-05-03 14:59:30 -0700 |
| commit | 4f1ff3de925d741b0b77c59bc1387cb940ad7c73 (patch) | |
| tree | d3e2d92f460276c89ce5136091baf78d0cbfd44b /drivers/hwtracing/coresight/coresight-tmc.c | |
| parent | b217601e9adce4d2dccc95a9e6814bdbf5a4a815 (diff) | |
coresight: tmc: keep track of memory width
Accessing the HW configuration register each time the memory
width is needed simply doesn't make sense. It is much more
efficient to read the value once and keep a reference for
later use.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hwtracing/coresight/coresight-tmc.c')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-tmc.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-tmc.c b/drivers/hwtracing/coresight/coresight-tmc.c index ae7525a2b94a..9e02ac963cd0 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.c +++ b/drivers/hwtracing/coresight/coresight-tmc.c @@ -186,6 +186,39 @@ static const struct file_operations tmc_fops = { .llseek = no_llseek, }; +static enum tmc_mem_intf_width tmc_get_memwidth(u32 devid) +{ + enum tmc_mem_intf_width memwidth; + + /* + * Excerpt from the TRM: + * + * DEVID::MEMWIDTH[10:8] + * 0x2 Memory interface databus is 32 bits wide. + * 0x3 Memory interface databus is 64 bits wide. + * 0x4 Memory interface databus is 128 bits wide. + * 0x5 Memory interface databus is 256 bits wide. + */ + switch (BMVAL(devid, 8, 10)) { + case 0x2: + memwidth = TMC_MEM_INTF_WIDTH_32BITS; + break; + case 0x3: + memwidth = TMC_MEM_INTF_WIDTH_64BITS; + break; + case 0x4: + memwidth = TMC_MEM_INTF_WIDTH_128BITS; + break; + case 0x5: + memwidth = TMC_MEM_INTF_WIDTH_256BITS; + break; + default: + memwidth = 0; + } + + return memwidth; +} + #define coresight_tmc_simple_func(name, offset) \ coresight_simple_func(struct tmc_drvdata, name, offset) @@ -299,6 +332,7 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id) devid = readl_relaxed(drvdata->base + CORESIGHT_DEVID); drvdata->config_type = BMVAL(devid, 6, 7); + drvdata->memwidth = tmc_get_memwidth(devid); if (drvdata->config_type == TMC_CONFIG_TYPE_ETR) { if (np) |