[SCSI] libsas: sgpio write support
Add SFF-8485 v0.7 / SAS-1 smp-write-gpio register support to libsas.
Defer SAS-2 support unless/until it defines an sgpio interface.
Minimum implementation needed to get the lights blinking.
try_test_sas_gpio_gp_bit() provides a common method to parse the
incoming write data (raw bitstream), and the to_sas_gpio_gp_bit() helper
routine can be used as a basis for the set/clear operations for the
'read' implementation. Host implementations parse as many bits
(ODx.[012]) as are locally supported and report the number of registers
successfully written. If the submitted data overruns the internal
number of registers available report the write as a success with the
number of bytes remaining reported in ->resid_len.
Example (assuming an active backplane) set the "identify" pattern for
the first 21 devices:
smp_write_gpio --count=2 --data=92,49,24,92,24,92,49,24 -t 4 --index=1 /dev/bsg/sas_hostX
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/libsas/sas_host_smp.c b/drivers/scsi/libsas/sas_host_smp.c
index 04ad8dd..e1aa178 100644
--- a/drivers/scsi/libsas/sas_host_smp.c
+++ b/drivers/scsi/libsas/sas_host_smp.c
@@ -51,6 +51,91 @@
resp_data[15] = rphy->identify.target_port_protocols;
}
+/**
+ * to_sas_gpio_gp_bit - given the gpio frame data find the byte/bit position of 'od'
+ * @od: od bit to find
+ * @data: incoming bitstream (from frame)
+ * @index: requested data register index (from frame)
+ * @count: total number of registers in the bitstream (from frame)
+ * @bit: bit position of 'od' in the returned byte
+ *
+ * returns NULL if 'od' is not in 'data'
+ *
+ * From SFF-8485 v0.7:
+ * "In GPIO_TX[1], bit 0 of byte 3 contains the first bit (i.e., OD0.0)
+ * and bit 7 of byte 0 contains the 32nd bit (i.e., OD10.1).
+ *
+ * In GPIO_TX[2], bit 0 of byte 3 contains the 33rd bit (i.e., OD10.2)
+ * and bit 7 of byte 0 contains the 64th bit (i.e., OD21.0)."
+ *
+ * The general-purpose (raw-bitstream) RX registers have the same layout
+ * although 'od' is renamed 'id' for 'input data'.
+ *
+ * SFF-8489 defines the behavior of the LEDs in response to the 'od' values.
+ */
+static u8 *to_sas_gpio_gp_bit(unsigned int od, u8 *data, u8 index, u8 count, u8 *bit)
+{
+ unsigned int reg;
+ u8 byte;
+
+ /* gp registers start at index 1 */
+ if (index == 0)
+ return NULL;
+
+ index--; /* make index 0-based */
+ if (od < index * 32)
+ return NULL;
+
+ od -= index * 32;
+ reg = od >> 5;
+
+ if (reg >= count)
+ return NULL;
+
+ od &= (1 << 5) - 1;
+ byte = 3 - (od >> 3);
+ *bit = od & ((1 << 3) - 1);
+
+ return &data[reg * 4 + byte];
+}
+
+int try_test_sas_gpio_gp_bit(unsigned int od, u8 *data, u8 index, u8 count)
+{
+ u8 *byte;
+ u8 bit;
+
+ byte = to_sas_gpio_gp_bit(od, data, index, count, &bit);
+ if (!byte)
+ return -1;
+
+ return (*byte >> bit) & 1;
+}
+EXPORT_SYMBOL(try_test_sas_gpio_gp_bit);
+
+static int sas_host_smp_write_gpio(struct sas_ha_struct *sas_ha, u8 *resp_data,
+ u8 reg_type, u8 reg_index, u8 reg_count,
+ u8 *req_data)
+{
+ struct sas_internal *i = to_sas_internal(sas_ha->core.shost->transportt);
+ int written;
+
+ if (i->dft->lldd_write_gpio == NULL) {
+ resp_data[2] = SMP_RESP_FUNC_UNK;
+ return 0;
+ }
+
+ written = i->dft->lldd_write_gpio(sas_ha, reg_type, reg_index,
+ reg_count, req_data);
+
+ if (written < 0) {
+ resp_data[2] = SMP_RESP_FUNC_FAILED;
+ written = 0;
+ } else
+ resp_data[2] = SMP_RESP_FUNC_ACC;
+
+ return written;
+}
+
static void sas_report_phy_sata(struct sas_ha_struct *sas_ha, u8 *resp_data,
u8 phy_id)
{
@@ -230,9 +315,23 @@
/* Can't implement; hosts have no routes */
break;
- case SMP_WRITE_GPIO_REG:
- /* FIXME: need GPIO support in the transport class */
+ case SMP_WRITE_GPIO_REG: {
+ /* SFF-8485 v0.7 */
+ const int base_frame_size = 11;
+ int to_write = req_data[4];
+
+ if (blk_rq_bytes(req) < base_frame_size + to_write * 4 ||
+ req->resid_len < base_frame_size + to_write * 4) {
+ resp_data[2] = SMP_RESP_INV_FRM_LEN;
+ break;
+ }
+
+ to_write = sas_host_smp_write_gpio(sas_ha, resp_data, req_data[2],
+ req_data[3], to_write, &req_data[8]);
+ req->resid_len -= base_frame_size + to_write * 4;
+ rsp->resid_len -= 8;
break;
+ }
case SMP_CONF_ROUTE_INFO:
/* Can't implement; hosts have no routes */