diff options
Diffstat (limited to 'drivers/spi/spi.c')
| -rw-r--r-- | drivers/spi/spi.c | 322 |
1 files changed, 249 insertions, 73 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 4adc56dabf..46f1535487 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -612,10 +612,21 @@ static int spi_dev_check(struct device *dev, void *data) { struct spi_device *spi = to_spi_device(dev); struct spi_device *new_spi = data; - - if (spi->controller == new_spi->controller && - spi_get_chipselect(spi, 0) == spi_get_chipselect(new_spi, 0)) - return -EBUSY; + int idx, nw_idx; + u8 cs, cs_nw; + + if (spi->controller == new_spi->controller) { + for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { + cs = spi_get_chipselect(spi, idx); + for (nw_idx = 0; nw_idx < SPI_CS_CNT_MAX; nw_idx++) { + cs_nw = spi_get_chipselect(new_spi, nw_idx); + if (cs != 0xFF && cs_nw != 0xFF && cs == cs_nw) { + dev_err(dev, "chipselect %d already in use\n", cs_nw); + return -EBUSY; + } + } + } + } return 0; } @@ -629,13 +640,32 @@ static int __spi_add_device(struct spi_device *spi) { struct spi_controller *ctlr = spi->controller; struct device *dev = ctlr->dev.parent; - int status; + int status, idx, nw_idx; + u8 cs, nw_cs; + + for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { + /* Chipselects are numbered 0..max; validate. */ + cs = spi_get_chipselect(spi, idx); + if (cs != 0xFF && cs >= ctlr->num_chipselect) { + dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, idx), + ctlr->num_chipselect); + return -EINVAL; + } + } - /* Chipselects are numbered 0..max; validate. */ - if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) { - dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0), - ctlr->num_chipselect); - return -EINVAL; + /* + * Make sure that multiple logical CS doesn't map to the same physical CS. + * For example, spi->chip_select[0] != spi->chip_select[1] and so on. + */ + for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { + cs = spi_get_chipselect(spi, idx); + for (nw_idx = idx + 1; nw_idx < SPI_CS_CNT_MAX; nw_idx++) { + nw_cs = spi_get_chipselect(spi, nw_idx); + if (cs != 0xFF && nw_cs != 0xFF && cs == nw_cs) { + dev_err(dev, "chipselect %d already in use\n", nw_cs); + return -EBUSY; + } + } } /* Set the bus ID string */ @@ -647,11 +677,8 @@ static int __spi_add_device(struct spi_device *spi) * its configuration. */ status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); - if (status) { - dev_err(dev, "chipselect %d already in use\n", - spi_get_chipselect(spi, 0)); + if (status) return status; - } /* Controller may unregister concurrently */ if (IS_ENABLED(CONFIG_SPI_DYNAMIC) && @@ -659,8 +686,15 @@ static int __spi_add_device(struct spi_device *spi) return -ENODEV; } - if (ctlr->cs_gpiods) - spi_set_csgpiod(spi, 0, ctlr->cs_gpiods[spi_get_chipselect(spi, 0)]); + if (ctlr->cs_gpiods) { + u8 cs; + + for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { + cs = spi_get_chipselect(spi, idx); + if (cs != 0xFF) + spi_set_csgpiod(spi, idx, ctlr->cs_gpiods[cs]); + } + } /* * Drivers may modify this initial i/o setup, but will @@ -701,6 +735,9 @@ int spi_add_device(struct spi_device *spi) struct spi_controller *ctlr = spi->controller; int status; + /* Set the bus ID string */ + spi_dev_set_name(spi); + mutex_lock(&ctlr->add_lock); status = __spi_add_device(spi); mutex_unlock(&ctlr->add_lock); @@ -727,6 +764,7 @@ struct spi_device *spi_new_device(struct spi_controller *ctlr, { struct spi_device *proxy; int status; + u8 idx; /* * NOTE: caller did any chip->bus_num checks necessary. @@ -742,6 +780,18 @@ struct spi_device *spi_new_device(struct spi_controller *ctlr, WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias)); + /* + * Zero(0) is a valid physical CS value and can be located at any + * logical CS in the spi->chip_select[]. If all the physical CS + * are initialized to 0 then It would be difficult to differentiate + * between a valid physical CS 0 & an unused logical CS whose physical + * CS can be 0. As a solution to this issue initialize all the CS to 0xFF. + * Now all the unused logical CS will have 0xFF physical CS value & can be + * ignore while performing physical CS validity checks. + */ + for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) + spi_set_chipselect(proxy, idx, 0xFF); + spi_set_chipselect(proxy, 0, chip->chip_select); proxy->max_speed_hz = chip->max_speed_hz; proxy->mode = chip->mode; @@ -750,6 +800,15 @@ struct spi_device *spi_new_device(struct spi_controller *ctlr, proxy->dev.platform_data = (void *) chip->platform_data; proxy->controller_data = chip->controller_data; proxy->controller_state = NULL; + /* + * spi->chip_select[i] gives the corresponding physical CS for logical CS i + * logical CS number is represented by setting the ith bit in spi->cs_index_mask + * So, for example, if spi->cs_index_mask = 0x01 then logical CS number is 0 and + * spi->chip_select[0] will give the physical CS. + * By default spi->chip_select[0] will hold the physical CS number so, set + * spi->cs_index_mask as 0x01. + */ + proxy->cs_index_mask = 0x01; if (chip->swnode) { status = device_add_software_node(&proxy->dev, chip->swnode); @@ -942,32 +1001,55 @@ static void spi_res_release(struct spi_controller *ctlr, struct spi_message *mes } /*-------------------------------------------------------------------------*/ +static inline bool spi_is_last_cs(struct spi_device *spi) +{ + u8 idx; + bool last = false; + + for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { + if ((spi->cs_index_mask >> idx) & 0x01) { + if (spi->controller->last_cs[idx] == spi_get_chipselect(spi, idx)) + last = true; + } + } + return last; +} + static void spi_set_cs(struct spi_device *spi, bool enable, bool force) { bool activate = enable; + u8 idx; /* * Avoid calling into the driver (or doing delays) if the chip select * isn't actually changing from the last time this was called. */ - if (!force && ((enable && spi->controller->last_cs == spi_get_chipselect(spi, 0)) || - (!enable && spi->controller->last_cs != spi_get_chipselect(spi, 0))) && + if (!force && ((enable && spi->controller->last_cs_index_mask == spi->cs_index_mask && + spi_is_last_cs(spi)) || + (!enable && spi->controller->last_cs_index_mask == spi->cs_index_mask && + !spi_is_last_cs(spi))) && (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH))) return; trace_spi_set_cs(spi, activate); - spi->controller->last_cs = enable ? spi_get_chipselect(spi, 0) : -1; + spi->controller->last_cs_index_mask = spi->cs_index_mask; + for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) + spi->controller->last_cs[idx] = enable ? spi_get_chipselect(spi, 0) : -1; spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH; - if ((spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) && !activate) - spi_delay_exec(&spi->cs_hold, NULL); - if (spi->mode & SPI_CS_HIGH) enable = !enable; - if (spi_get_csgpiod(spi, 0)) { + /* + * Handle chip select delays for GPIO based CS or controllers without + * programmable chip select timing. + */ + if ((spi_is_csgpiod(spi) || !spi->controller->set_cs_timing) && !activate) + spi_delay_exec(&spi->cs_hold, NULL); + + if (spi_is_csgpiod(spi)) { if (!(spi->mode & SPI_NO_CS)) { /* * Historically ACPI has no means of the GPIO polarity and @@ -979,11 +1061,23 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force) * ambiguity. That's why we use enable, that takes SPI_CS_HIGH * into account. */ - if (has_acpi_companion(&spi->dev)) - gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), !enable); - else - /* Polarity handled by GPIO library */ - gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), activate); + for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { + if (((spi->cs_index_mask >> idx) & 0x01) && + spi_get_csgpiod(spi, idx)) { + if (has_acpi_companion(&spi->dev)) + gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx), + !enable); + else + /* Polarity handled by GPIO library */ + gpiod_set_value_cansleep(spi_get_csgpiod(spi, idx), + activate); + + if (activate) + spi_delay_exec(&spi->cs_setup, NULL); + else + spi_delay_exec(&spi->cs_inactive, NULL); + } + } } /* Some SPI masters need both GPIO CS & slave_select */ if ((spi->controller->flags & SPI_CONTROLLER_GPIO_SS) && @@ -993,7 +1087,7 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force) spi->controller->set_cs(spi, !enable); } - if (spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) { + if (spi_is_csgpiod(spi) || !spi->controller->set_cs_timing) { if (activate) spi_delay_exec(&spi->cs_setup, NULL); else @@ -1361,6 +1455,9 @@ static int spi_transfer_wait(struct spi_controller *ctlr, "SPI transfer timed out\n"); return -ETIMEDOUT; } + + if (xfer->error & SPI_TRANS_FAIL_IO) + return -EIO; } return 0; @@ -1654,13 +1751,37 @@ static int __spi_pump_transfer_message(struct spi_controller *ctlr, trace_spi_message_start(msg); - ret = spi_split_transfers_maxsize(ctlr, msg, - spi_max_transfer_size(msg->spi), - GFP_KERNEL | GFP_DMA); - if (ret) { - msg->status = ret; - spi_finalize_current_message(ctlr); - return ret; + /* + * If an SPI controller does not support toggling the CS line on each + * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO + * for the CS line, we can emulate the CS-per-word hardware function by + * splitting transfers into one-word transfers and ensuring that + * cs_change is set for each transfer. + */ + if ((msg->spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || + spi_is_csgpiod(msg->spi))) { + ret = spi_split_transfers_maxwords(ctlr, msg, 1, GFP_KERNEL); + if (ret) { + msg->status = ret; + spi_finalize_current_message(ctlr); + return ret; + } + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + /* Don't change cs_change on the last entry in the list */ + if (list_is_last(&xfer->transfer_list, &msg->transfers)) + break; + xfer->cs_change = 1; + } + } else { + ret = spi_split_transfers_maxsize(ctlr, msg, + spi_max_transfer_size(msg->spi), + GFP_KERNEL | GFP_DMA); + if (ret) { + msg->status = ret; + spi_finalize_current_message(ctlr); + return ret; + } } if (ctlr->prepare_message) { @@ -2226,8 +2347,8 @@ static void of_spi_parse_dt_cs_delay(struct device_node *nc, static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi, struct device_node *nc) { - u32 value; - int rc; + u32 value, cs[SPI_CS_CNT_MAX]; + int rc, idx; /* Mode (clock phase/polarity/etc.) */ if (of_property_read_bool(nc, "spi-cpha")) @@ -2299,14 +2420,53 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi, return 0; } + if (ctlr->num_chipselect > SPI_CS_CNT_MAX) { + dev_err(&ctlr->dev, "No. of CS is more than max. no. of supported CS\n"); + return -EINVAL; + } + + /* + * Zero(0) is a valid physical CS value and can be located at any + * logical CS in the spi->chip_select[]. If all the physical CS + * are initialized to 0 then It would be difficult to differentiate + * between a valid physical CS 0 & an unused logical CS whose physical + * CS can be 0. As a solution to this issue initialize all the CS to 0xFF. + * Now all the unused logical CS will have 0xFF physical CS value & can be + * ignore while performing physical CS validity checks. + */ + for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) + spi_set_chipselect(spi, idx, 0xFF); + /* Device address */ - rc = of_property_read_u32(nc, "reg", &value); - if (rc) { + rc = of_property_read_variable_u32_array(nc, "reg", &cs[0], 1, + SPI_CS_CNT_MAX); + if (rc < 0) { dev_err(&ctlr->dev, "%pOF has no valid 'reg' property (%d)\n", nc, rc); return rc; } - spi_set_chipselect(spi, 0, value); + if (rc > ctlr->num_chipselect) { + dev_err(&ctlr->dev, "%pOF has number of CS > ctlr->num_chipselect (%d)\n", + nc, rc); + return rc; + } + if ((of_property_read_bool(nc, "parallel-memories")) && + (!(ctlr->flags & SPI_CONTROLLER_MULTI_CS))) { + dev_err(&ctlr->dev, "SPI controller doesn't support multi CS\n"); + return -EINVAL; + } + for (idx = 0; idx < rc; idx++) + spi_set_chipselect(spi, idx, cs[idx]); + + /* + * spi->chip_select[i] gives the corresponding physical CS for logical CS i + * logical CS number is represented by setting the ith bit in spi->cs_index_mask + * So, for example, if spi->cs_index_mask = 0x01 then logical CS number is 0 and + * spi->chip_select[0] will give the physical CS. + * By default spi->chip_select[0] will hold the physical CS number so, set + * spi->cs_index_mask as 0x01. + */ + spi->cs_index_mask = 0x01; /* Device speed */ if (!of_property_read_u32(nc, "spi-max-frequency", &value)) @@ -2412,6 +2572,7 @@ struct spi_device *spi_new_ancillary_device(struct spi_device *spi, struct spi_controller *ctlr = spi->controller; struct spi_device *ancillary; int rc = 0; + u8 idx; /* Alloc an spi_device */ ancillary = spi_alloc_device(ctlr); @@ -2422,12 +2583,33 @@ struct spi_device *spi_new_ancillary_device(struct spi_device *spi, strscpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias)); + /* + * Zero(0) is a valid physical CS value and can be located at any + * logical CS in the spi->chip_select[]. If all the physical CS + * are initialized to 0 then It would be difficult to differentiate + * between a valid physical CS 0 & an unused logical CS whose physical + * CS can be 0. As a solution to this issue initialize all the CS to 0xFF. + * Now all the unused logical CS will have 0xFF physical CS value & can be + * ignore while performing physical CS validity checks. + */ + for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) + spi_set_chipselect(ancillary, idx, 0xFF); + /* Use provided chip-select for ancillary device */ spi_set_chipselect(ancillary, 0, chip_select); /* Take over SPI mode/speed from SPI main device */ ancillary->max_speed_hz = spi->max_speed_hz; ancillary->mode = spi->mode; + /* + * spi->chip_select[i] gives the corresponding physical CS for logical CS i + * logical CS number is represented by setting the ith bit in spi->cs_index_mask + * So, for example, if spi->cs_index_mask = 0x01 then logical CS number is 0 and + * spi->chip_select[0] will give the physical CS. + * By default spi->chip_select[0] will hold the physical CS number so, set + * spi->cs_index_mask as 0x01. + */ + ancillary->cs_index_mask = 0x01; WARN_ON(!mutex_is_locked(&ctlr->add_lock)); @@ -2630,6 +2812,7 @@ struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr, struct acpi_spi_lookup lookup = {}; struct spi_device *spi; int ret; + u8 idx; if (!ctlr && index == -1) return ERR_PTR(-EINVAL); @@ -2665,12 +2848,33 @@ struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr, return ERR_PTR(-ENOMEM); } + /* + * Zero(0) is a valid physical CS value and can be located at any + * logical CS in the spi->chip_select[]. If all the physical CS + * are initialized to 0 then It would be difficult to differentiate + * between a valid physical CS 0 & an unused logical CS whose physical + * CS can be 0. As a solution to this issue initialize all the CS to 0xFF. + * Now all the unused logical CS will have 0xFF physical CS value & can be + * ignore while performing physical CS validity checks. + */ + for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) + spi_set_chipselect(spi, idx, 0xFF); + ACPI_COMPANION_SET(&spi->dev, adev); spi->max_speed_hz = lookup.max_speed_hz; spi->mode |= lookup.mode; spi->irq = lookup.irq; spi->bits_per_word = lookup.bits_per_word; spi_set_chipselect(spi, 0, lookup.chip_select); + /* + * spi->chip_select[i] gives the corresponding physical CS for logical CS i + * logical CS number is represented by setting the ith bit in spi->cs_index_mask + * So, for example, if spi->cs_index_mask = 0x01 then logical CS number is 0 and + * spi->chip_select[0] will give the physical CS. + * By default spi->chip_select[0] will hold the physical CS number so, set + * spi->cs_index_mask as 0x01. + */ + spi->cs_index_mask = 0x01; return spi; } @@ -3104,6 +3308,7 @@ int spi_register_controller(struct spi_controller *ctlr) struct boardinfo *bi; int first_dynamic; int status; + int idx; if (!dev) return -ENODEV; @@ -3168,7 +3373,8 @@ int spi_register_controller(struct spi_controller *ctlr) } /* Setting last_cs to -1 means no chip selected */ - ctlr->last_cs = -1; + for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) + ctlr->last_cs[idx] = -1; status = device_add(&ctlr->dev); if (status < 0) @@ -3885,33 +4091,7 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) if (list_empty(&message->transfers)) return -EINVAL; - /* - * If an SPI controller does not support toggling the CS line on each - * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO - * for the CS line, we can emulate the CS-per-word hardware function by - * splitting transfers into one-word transfers and ensuring that - * cs_change is set for each transfer. - */ - if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || - spi_get_csgpiod(spi, 0))) { - size_t maxsize = BITS_TO_BYTES(spi->bits_per_word); - int ret; - - /* spi_split_transfers_maxsize() requires message->spi */ - message->spi = spi; - - ret = spi_split_transfers_maxsize(ctlr, message, maxsize, - GFP_KERNEL); - if (ret) - return ret; - - list_for_each_entry(xfer, &message->transfers, transfer_list) { - /* Don't change cs_change on the last entry in the list */ - if (list_is_last(&xfer->transfer_list, &message->transfers)) - break; - xfer->cs_change = 1; - } - } + message->spi = spi; /* * Half-duplex links include original MicroWire, and ones with @@ -4036,8 +4216,6 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) if (!ctlr->transfer) return -ENOTSUPP; - message->spi = spi; - SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_async); SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_async); @@ -4217,8 +4395,6 @@ static int __spi_sync(struct spi_device *spi, struct spi_message *message) if (status != 0) return status; - message->spi = spi; - SPI_STATISTICS_INCREMENT_FIELD(ctlr->pcpu_statistics, spi_sync); SPI_STATISTICS_INCREMENT_FIELD(spi->pcpu_statistics, spi_sync); |