+/**
+ * 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;
+}
+