From eeaceb8b7d1fb64b6030249ca0dd1d902ef3069e Mon Sep 17 00:00:00 2001 From: Baolin Wang Date: Thu, 16 Aug 2018 20:54:49 +0800 Subject: spi: Introduce one new field to set word delay For some SPI controllers, after each word size (specified by bits_per_word) transimission, the hardware need some delay to make sure the slave has enough time to receive the whole data. So introducing one new 'word_delay' field of struct spi_tansfer for slave devices to set this inter word delay time. Signed-off-by: Baolin Wang Signed-off-by: Mark Brown --- include/linux/spi/spi.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/spi/spi.h') diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index a64235e05321..d698f9db3484 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -711,6 +711,8 @@ extern void spi_res_release(struct spi_controller *ctlr, * @delay_usecs: microseconds to delay after this transfer before * (optionally) changing the chipselect status, then starting * the next transfer or completing this @spi_message. + * @word_delay: clock cycles to inter word delay after each word size + * (set by bits_per_word) transmission. * @transfer_list: transfers are sequenced through @spi_message.transfers * @tx_sg: Scatterlist for transmit, currently not for client use * @rx_sg: Scatterlist for receive, currently not for client use @@ -793,6 +795,7 @@ struct spi_transfer { u8 bits_per_word; u16 delay_usecs; u32 speed_hz; + u16 word_delay; struct list_head transfer_list; }; -- cgit v1.2.3 From 0baf9eb25572eea0cf48249c1d152d8373956a7c Mon Sep 17 00:00:00 2001 From: David Lechner Date: Wed, 12 Sep 2018 19:39:17 -0500 Subject: spi: add new SPI_CS_WORD flag This adds a new SPI mode flag, SPI_CS_WORD, that is used to indicate that a SPI device requires the chip select to be toggled after each word that is transferred. Signed-off-by: David Lechner Signed-off-by: Mark Brown --- include/linux/spi/spi.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux/spi/spi.h') diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index a64235e05321..7cc1466111f5 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -163,6 +163,7 @@ struct spi_device { #define SPI_TX_QUAD 0x200 /* transmit with 4 wires */ #define SPI_RX_DUAL 0x400 /* receive with 2 wires */ #define SPI_RX_QUAD 0x800 /* receive with 4 wires */ +#define SPI_CS_WORD 0x1000 /* toggle cs after each word */ int irq; void *controller_state; void *controller_data; @@ -177,7 +178,6 @@ struct spi_device { * the controller talks to each chip, like: * - memory packing (12 bit samples into low bits, others zeroed) * - priority - * - drop chipselect after each word * - chipselect delays * - ... */ -- cgit v1.2.3 From b445bfcb9081ae90fec90b828f3aacc565776901 Mon Sep 17 00:00:00 2001 From: Marco Felsch Date: Tue, 25 Sep 2018 11:42:28 +0200 Subject: spi: switch to SPDX license identifier Use the appropriate SPDX license identifier and drop the previous license text. Signed-off-by: Marco Felsch Signed-off-by: Mark Brown --- drivers/spi/spi.c | 11 +---------- include/linux/spi/spi.h | 13 ++----------- 2 files changed, 3 insertions(+), 21 deletions(-) (limited to 'include/linux/spi/spi.h') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index a358acdd98d3..2cfc3df821f6 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1,18 +1,9 @@ +// SPDX-License-Identifier: GPL-2.0-or-later /* * SPI init/core code * * Copyright (C) 2005 David Brownell * Copyright (C) 2008 Secret Lab Technologies Ltd. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. */ #include diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 7bb36145e2ba..f08824ea1968 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -1,15 +1,6 @@ -/* - * Copyright (C) 2005 David Brownell +/* SPDX-License-Identifier: GPL-2.0-or-later * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. + * Copyright (C) 2005 David Brownell */ #ifndef __LINUX_SPI_H -- cgit v1.2.3 From 5f143af7501e7c435c56e181a655493edaa92509 Mon Sep 17 00:00:00 2001 From: Marco Felsch Date: Tue, 25 Sep 2018 11:42:29 +0200 Subject: spi: make OF helper available for others The of_find_spi_device_by_node() helper function is useful for other modules too. Export the funciton as GPL like all other spi helper functions and make it available if CONFIG_OF is enabled, because it isn't related to the CONFIG_OF_DYNAMIC context. Finally add a stub if CONFIG_OF isn't enabled, so others must not care about it. Signed-off-by: Marco Felsch Signed-off-by: Mark Brown --- drivers/spi/spi.c | 7 +++++-- include/linux/spi/spi.h | 17 ++++++++++++++++- 2 files changed, 21 insertions(+), 3 deletions(-) (limited to 'include/linux/spi/spi.h') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index ec395a6baf9c..f939f585e917 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -3314,20 +3314,23 @@ EXPORT_SYMBOL_GPL(spi_write_then_read); /*-------------------------------------------------------------------------*/ -#if IS_ENABLED(CONFIG_OF_DYNAMIC) +#if IS_ENABLED(CONFIG_OF) static int __spi_of_device_match(struct device *dev, void *data) { return dev->of_node == data; } /* must call put_device() when done with returned spi_device device */ -static struct spi_device *of_find_spi_device_by_node(struct device_node *node) +struct spi_device *of_find_spi_device_by_node(struct device_node *node) { struct device *dev = bus_find_device(&spi_bus_type, NULL, node, __spi_of_device_match); return dev ? to_spi_device(dev) : NULL; } +EXPORT_SYMBOL_GPL(of_find_spi_device_by_node); +#endif /* IS_ENABLED(CONFIG_OF) */ +#if IS_ENABLED(CONFIG_OF_DYNAMIC) static int __spi_of_controller_match(struct device *dev, const void *data) { return dev->of_node == data; diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index a64235e05321..e9ebfcd2e932 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -1277,7 +1277,6 @@ spi_register_board_info(struct spi_board_info const *info, unsigned n) { return 0; } #endif - /* If you're hotplugging an adapter with devices (parport, usb, etc) * use spi_new_device() to describe each device. You can also call * spi_unregister_device() to start making that device vanish, but @@ -1309,6 +1308,22 @@ spi_transfer_is_last(struct spi_controller *ctlr, struct spi_transfer *xfer) return list_is_last(&xfer->transfer_list, &ctlr->cur_msg->transfers); } +/* OF support code */ +#if IS_ENABLED(CONFIG_OF) + +/* must call put_device() when done with returned spi_device device */ +extern struct spi_device * +of_find_spi_device_by_node(struct device_node *node); + +#else + +static inline struct spi_device * +of_find_spi_device_by_node(struct device_node *node) +{ + return NULL; +} + +#endif /* IS_ENABLED(CONFIG_OF) */ /* Compatibility layer */ #define spi_master spi_controller -- cgit v1.2.3 From 5039563e7c25eccd7fec1de6706011009d1c5665 Mon Sep 17 00:00:00 2001 From: Trent Piepho Date: Thu, 20 Sep 2018 19:18:32 +0000 Subject: spi: Add driver_override SPI device attribute MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This attribute works the same was as the identically named attribute for PCI, AMBA, and platform devices. For reference, see: commit 3cf385713460 ("ARM: 8256/1: driver coamba: add device binding path 'driver_override'") commit 3d713e0e382e ("driver core: platform: add device binding path 'driver_override'") commit 782a985d7af2 ("PCI: Introduce new device binding path using pci_dev.driver_override") If the name of a driver is written to this attribute, then the device will bind to the named driver and only the named driver. The device will bind to the driver even if the driver does not list the device in its id table. This behavior is different than the driver's bind attribute, which only allows binding to devices that are listed as supported by the driver. It can be used to bind a generic driver, like spidev, to a device. Signed-off-by: Trent Piepho Reviewed-by: Jan Kundrát Tested-by: Jan Kundrát Reviewed-by: Geert Uytterhoeven Signed-off-by: Mark Brown --- drivers/spi/spi.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/spi/spi.h | 1 + 2 files changed, 52 insertions(+) (limited to 'include/linux/spi/spi.h') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 2cfc3df821f6..fcbd4cfd2818 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -51,6 +51,7 @@ static void spidev_release(struct device *dev) spi->controller->cleanup(spi); spi_controller_put(spi->controller); + kfree(spi->driver_override); kfree(spi); } @@ -68,6 +69,51 @@ modalias_show(struct device *dev, struct device_attribute *a, char *buf) } static DEVICE_ATTR_RO(modalias); +static ssize_t driver_override_store(struct device *dev, + struct device_attribute *a, + const char *buf, size_t count) +{ + struct spi_device *spi = to_spi_device(dev); + const char *end = memchr(buf, '\n', count); + const size_t len = end ? end - buf : count; + const char *driver_override, *old; + + /* We need to keep extra room for a newline when displaying value */ + if (len >= (PAGE_SIZE - 1)) + return -EINVAL; + + driver_override = kstrndup(buf, len, GFP_KERNEL); + if (!driver_override) + return -ENOMEM; + + device_lock(dev); + old = spi->driver_override; + if (len) { + spi->driver_override = driver_override; + } else { + /* Emptry string, disable driver override */ + spi->driver_override = NULL; + kfree(driver_override); + } + device_unlock(dev); + kfree(old); + + return count; +} + +static ssize_t driver_override_show(struct device *dev, + struct device_attribute *a, char *buf) +{ + const struct spi_device *spi = to_spi_device(dev); + ssize_t len; + + device_lock(dev); + len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : ""); + device_unlock(dev); + return len; +} +static DEVICE_ATTR_RW(driver_override); + #define SPI_STATISTICS_ATTRS(field, file) \ static ssize_t spi_controller_##field##_show(struct device *dev, \ struct device_attribute *attr, \ @@ -149,6 +195,7 @@ SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu"); static struct attribute *spi_dev_attrs[] = { &dev_attr_modalias.attr, + &dev_attr_driver_override.attr, NULL, }; @@ -296,6 +343,10 @@ static int spi_match_device(struct device *dev, struct device_driver *drv) const struct spi_device *spi = to_spi_device(dev); const struct spi_driver *sdrv = to_spi_driver(drv); + /* Check override first, and if set, only use the named driver */ + if (spi->driver_override) + return strcmp(spi->driver_override, drv->name) == 0; + /* Attempt an OF style match */ if (of_driver_match_device(dev, drv)) return 1; diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index f08824ea1968..3de9958ca28b 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -159,6 +159,7 @@ struct spi_device { void *controller_state; void *controller_data; char modalias[SPI_NAME_SIZE]; + const char *driver_override; int cs_gpio; /* chip select gpio */ /* the statistics */ -- cgit v1.2.3