diff options
| -rw-r--r-- | drivers/spi/spi.c | 259 | ||||
| -rw-r--r-- | include/linux/spi/spi.h | 51 |
2 files changed, 258 insertions, 52 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 8ead7acb99f3..45b6898cf0ee 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 +1001,51 @@ 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)) { + if (spi_is_csgpiod(spi)) { + if (!spi->controller->set_cs_timing && !activate) + spi_delay_exec(&spi->cs_hold, NULL); + if (!(spi->mode & SPI_NO_CS)) { /* * Historically ACPI has no means of the GPIO polarity and @@ -979,26 +1057,38 @@ 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) && spi->controller->set_cs) spi->controller->set_cs(spi, !enable); + + if (!spi->controller->set_cs_timing) { + if (activate) + spi_delay_exec(&spi->cs_setup, NULL); + else + spi_delay_exec(&spi->cs_inactive, NULL); + } } else if (spi->controller->set_cs) { spi->controller->set_cs(spi, !enable); } - - if (spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) { - if (activate) - spi_delay_exec(&spi->cs_setup, NULL); - else - spi_delay_exec(&spi->cs_inactive, NULL); - } } #ifdef CONFIG_HAS_DMA @@ -2222,8 +2312,8 @@ 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")) @@ -2295,14 +2385,53 @@ 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)) @@ -2408,6 +2537,7 @@ 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); @@ -2418,12 +2548,33 @@ 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)); @@ -2626,6 +2777,7 @@ 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); @@ -2661,12 +2813,33 @@ 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; } @@ -3100,6 +3273,7 @@ int spi_register_controller(struct spi_controller *ctlr) struct boardinfo *bi; int first_dynamic; int status; + int idx; if (!dev) return -ENODEV; @@ -3164,7 +3338,8 @@ 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) @@ -3889,7 +4064,7 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) * cs_change is set for each transfer. */ if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || - spi_get_csgpiod(spi, 0))) { + spi_is_csgpiod(spi))) { size_t maxsize = BITS_TO_BYTES(spi->bits_per_word); int ret; diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 255a0562aea5..50622054b6af 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -20,6 +20,9 @@ #include <uapi/linux/spi/spi.h> +/* Max no. of CS supported per spi device */ +#define SPI_CS_CNT_MAX 4 + struct dma_chan; struct software_node; struct ptp_system_timestamp; @@ -132,7 +135,8 @@ extern void spi_transfer_cs_change_delay_exec(struct spi_message *msg, * @max_speed_hz: Maximum clock rate to be used with this chip * (on this board); may be changed by the device's driver. * The spi_transfer.speed_hz can override this for each transfer. - * @chip_select: Chipselect, distinguishing chips handled by @controller. + * @chip_select: Array of physical chipselect, spi->chipselect[i] gives + * the corresponding physical CS for logical CS i. * @mode: The spi mode defines how data is clocked out and in. * This may be changed by the device's driver. * The "active low" default for chipselect mode can be overridden @@ -157,8 +161,8 @@ extern void spi_transfer_cs_change_delay_exec(struct spi_message *msg, * the device will bind to the named driver and only the named driver. * Do not set directly, because core frees it; use driver_set_override() to * set or clear it. - * @cs_gpiod: GPIO descriptor of the chipselect line (optional, NULL when - * not using a GPIO line) + * @cs_gpiod: Array of GPIO descriptors of the corresponding chipselect lines + * (optional, NULL when not using a GPIO line) * @word_delay: delay to be inserted between consecutive * words of a transfer * @cs_setup: delay to be introduced by the controller after CS is asserted @@ -167,6 +171,7 @@ extern void spi_transfer_cs_change_delay_exec(struct spi_message *msg, * deasserted. If @cs_change_delay is used from @spi_transfer, then the * two delays will be added up. * @pcpu_statistics: statistics for the spi_device + * @cs_index_mask: Bit mask of the active chipselect(s) in the chipselect array * * A @spi_device is used to interchange data between an SPI slave * (usually a discrete chip) and CPU memory. @@ -182,7 +187,7 @@ struct spi_device { struct spi_controller *controller; struct spi_controller *master; /* Compatibility layer */ u32 max_speed_hz; - u8 chip_select; + u8 chip_select[SPI_CS_CNT_MAX]; u8 bits_per_word; bool rt; #define SPI_NO_TX BIT(31) /* No transmit wire */ @@ -213,7 +218,7 @@ struct spi_device { void *controller_data; char modalias[SPI_NAME_SIZE]; const char *driver_override; - struct gpio_desc *cs_gpiod; /* Chip select GPIO descriptor */ + struct gpio_desc *cs_gpiod[SPI_CS_CNT_MAX]; /* Chip select gpio desc */ struct spi_delay word_delay; /* Inter-word delay */ /* CS delays */ struct spi_delay cs_setup; @@ -223,6 +228,13 @@ struct spi_device { /* The statistics */ struct spi_statistics __percpu *pcpu_statistics; + /* Bit mask of the chipselect(s) that the driver need to use from + * the chipselect array.When the controller is capable to handle + * multiple chip selects & memories are connected in parallel + * then more than one bit need to be set in cs_index_mask. + */ + u32 cs_index_mask : SPI_CS_CNT_MAX; + /* * Likely need more hooks for more protocol options affecting how * the controller talks to each chip, like: @@ -279,22 +291,33 @@ static inline void *spi_get_drvdata(const struct spi_device *spi) static inline u8 spi_get_chipselect(const struct spi_device *spi, u8 idx) { - return spi->chip_select; + return spi->chip_select[idx]; } static inline void spi_set_chipselect(struct spi_device *spi, u8 idx, u8 chipselect) { - spi->chip_select = chipselect; + spi->chip_select[idx] = chipselect; } static inline struct gpio_desc *spi_get_csgpiod(const struct spi_device *spi, u8 idx) { - return spi->cs_gpiod; + return spi->cs_gpiod[idx]; } static inline void spi_set_csgpiod(struct spi_device *spi, u8 idx, struct gpio_desc *csgpiod) { - spi->cs_gpiod = csgpiod; + spi->cs_gpiod[idx] = csgpiod; +} + +static inline bool spi_is_csgpiod(struct spi_device *spi) +{ + u8 idx; + + for (idx = 0; idx < SPI_CS_CNT_MAX; idx++) { + if (spi_get_csgpiod(spi, idx)) + return true; + } + return false; } /** @@ -399,6 +422,8 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch * @bus_lock_spinlock: spinlock for SPI bus locking * @bus_lock_mutex: mutex for exclusion of multiple callers * @bus_lock_flag: indicates that the SPI bus is locked for exclusive use + * @multi_cs_cap: indicates that the SPI Controller can assert/de-assert + * more than one chip select at once. * @setup: updates the device mode and clocking records used by a * device's SPI controller; protocol code may call this. This * must fail if an unrecognized or unsupported mode is requested. @@ -567,6 +592,11 @@ struct spi_controller { #define SPI_CONTROLLER_MUST_TX BIT(4) /* Requires tx */ #define SPI_CONTROLLER_GPIO_SS BIT(5) /* GPIO CS must select slave */ #define SPI_CONTROLLER_SUSPENDED BIT(6) /* Currently suspended */ + /* + * The spi-controller has multi chip select capability and can + * assert/de-assert more than one chip select at once. + */ +#define SPI_CONTROLLER_MULTI_CS BIT(7) /* Flag indicating if the allocation of this struct is devres-managed */ bool devm_allocated; @@ -677,7 +707,8 @@ struct spi_controller { bool rt; bool auto_runtime_pm; bool cur_msg_mapped; - char last_cs; + char last_cs[SPI_CS_CNT_MAX]; + char last_cs_index_mask; bool last_cs_mode_high; bool fallback; struct completion xfer_completion; |