From 83ca0efb3e1e5b765d8b8a6bcb2e681f51b7a944 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= Date: Tue, 26 Apr 2016 09:23:12 +0000 Subject: kernel: backport support for accelerated SPI flash read MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Rafał Miłecki SVN-Revision: 49233 --- ...ce-accelerated-read-support-for-spi-flash.patch | 179 +++++++++++++++++++++ 1 file changed, 179 insertions(+) create mode 100644 target/linux/generic/patches-4.4/080-spi-introduce-accelerated-read-support-for-spi-flash.patch (limited to 'target/linux/generic/patches-4.4/080-spi-introduce-accelerated-read-support-for-spi-flash.patch') diff --git a/target/linux/generic/patches-4.4/080-spi-introduce-accelerated-read-support-for-spi-flash.patch b/target/linux/generic/patches-4.4/080-spi-introduce-accelerated-read-support-for-spi-flash.patch new file mode 100644 index 0000000000..5e116b0bbf --- /dev/null +++ b/target/linux/generic/patches-4.4/080-spi-introduce-accelerated-read-support-for-spi-flash.patch @@ -0,0 +1,179 @@ +From 556351f14e74db4cd3ddde386457edce7bf0b27f Mon Sep 17 00:00:00 2001 +From: Vignesh R +Date: Fri, 11 Dec 2015 09:39:56 +0530 +Subject: [PATCH] spi: introduce accelerated read support for spi flash devices + +In addition to providing direct access to SPI bus, some spi controller +hardwares (like ti-qspi) provide special port (like memory mapped port) +that are optimized to improve SPI flash read performance. +This means the controller can automatically send the SPI signals +required to read data from the SPI flash device. +For this, SPI controller needs to know flash specific information like +read command to use, dummy bytes and address width. + +Introduce spi_flash_read() interface to support accelerated read +over SPI flash devices. SPI master drivers can implement this callback to +support interfaces such as memory mapped read etc. m25p80 flash driver +and other flash drivers can call this make use of such interfaces. The +interface should only be used with SPI flashes and cannot be used with +other SPI devices. + +Signed-off-by: Vignesh R +Signed-off-by: Mark Brown +--- + +--- a/drivers/spi/spi.c ++++ b/drivers/spi/spi.c +@@ -1135,6 +1135,7 @@ static void __spi_pump_messages(struct s + } + } + ++ mutex_lock(&master->bus_lock_mutex); + trace_spi_message_start(master->cur_msg); + + if (master->prepare_message) { +@@ -1144,6 +1145,7 @@ static void __spi_pump_messages(struct s + "failed to prepare message: %d\n", ret); + master->cur_msg->status = ret; + spi_finalize_current_message(master); ++ mutex_unlock(&master->bus_lock_mutex); + return; + } + master->cur_msg_prepared = true; +@@ -1153,6 +1155,7 @@ static void __spi_pump_messages(struct s + if (ret) { + master->cur_msg->status = ret; + spi_finalize_current_message(master); ++ mutex_unlock(&master->bus_lock_mutex); + return; + } + +@@ -1160,8 +1163,10 @@ static void __spi_pump_messages(struct s + if (ret) { + dev_err(&master->dev, + "failed to transfer one message from queue\n"); ++ mutex_unlock(&master->bus_lock_mutex); + return; + } ++ mutex_unlock(&master->bus_lock_mutex); + } + + /** +@@ -2329,6 +2334,46 @@ int spi_async_locked(struct spi_device * + EXPORT_SYMBOL_GPL(spi_async_locked); + + ++int spi_flash_read(struct spi_device *spi, ++ struct spi_flash_read_message *msg) ++ ++{ ++ struct spi_master *master = spi->master; ++ int ret; ++ ++ if ((msg->opcode_nbits == SPI_NBITS_DUAL || ++ msg->addr_nbits == SPI_NBITS_DUAL) && ++ !(spi->mode & (SPI_TX_DUAL | SPI_TX_QUAD))) ++ return -EINVAL; ++ if ((msg->opcode_nbits == SPI_NBITS_QUAD || ++ msg->addr_nbits == SPI_NBITS_QUAD) && ++ !(spi->mode & SPI_TX_QUAD)) ++ return -EINVAL; ++ if (msg->data_nbits == SPI_NBITS_DUAL && ++ !(spi->mode & (SPI_RX_DUAL | SPI_RX_QUAD))) ++ return -EINVAL; ++ if (msg->data_nbits == SPI_NBITS_QUAD && ++ !(spi->mode & SPI_RX_QUAD)) ++ return -EINVAL; ++ ++ if (master->auto_runtime_pm) { ++ ret = pm_runtime_get_sync(master->dev.parent); ++ if (ret < 0) { ++ dev_err(&master->dev, "Failed to power device: %d\n", ++ ret); ++ return ret; ++ } ++ } ++ mutex_lock(&master->bus_lock_mutex); ++ ret = master->spi_flash_read(spi, msg); ++ mutex_unlock(&master->bus_lock_mutex); ++ if (master->auto_runtime_pm) ++ pm_runtime_put(master->dev.parent); ++ ++ return ret; ++} ++EXPORT_SYMBOL_GPL(spi_flash_read); ++ + /*-------------------------------------------------------------------------*/ + + /* Utility methods for SPI master protocol drivers, layered on +--- a/include/linux/spi/spi.h ++++ b/include/linux/spi/spi.h +@@ -25,6 +25,7 @@ + struct dma_chan; + struct spi_master; + struct spi_transfer; ++struct spi_flash_read_message; + + /* + * INTERFACES between SPI master-side drivers and SPI infrastructure. +@@ -361,6 +362,8 @@ static inline void spi_unregister_driver + * @handle_err: the subsystem calls the driver to handle an error that occurs + * in the generic implementation of transfer_one_message(). + * @unprepare_message: undo any work done by prepare_message(). ++ * @spi_flash_read: to support spi-controller hardwares that provide ++ * accelerated interface to read from flash devices. + * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS + * number. Any individual value may be -ENOENT for CS lines that + * are not GPIOs (driven by the SPI controller itself). +@@ -507,6 +510,8 @@ struct spi_master { + struct spi_message *message); + int (*unprepare_message)(struct spi_master *master, + struct spi_message *message); ++ int (*spi_flash_read)(struct spi_device *spi, ++ struct spi_flash_read_message *msg); + + /* + * These hooks are for drivers that use a generic implementation +@@ -999,6 +1004,42 @@ static inline ssize_t spi_w8r16be(struct + return be16_to_cpu(result); + } + ++/** ++ * struct spi_flash_read_message - flash specific information for ++ * spi-masters that provide accelerated flash read interfaces ++ * @buf: buffer to read data ++ * @from: offset within the flash from where data is to be read ++ * @len: length of data to be read ++ * @retlen: actual length of data read ++ * @read_opcode: read_opcode to be used to communicate with flash ++ * @addr_width: number of address bytes ++ * @dummy_bytes: number of dummy bytes ++ * @opcode_nbits: number of lines to send opcode ++ * @addr_nbits: number of lines to send address ++ * @data_nbits: number of lines for data ++ */ ++struct spi_flash_read_message { ++ void *buf; ++ loff_t from; ++ size_t len; ++ size_t retlen; ++ u8 read_opcode; ++ u8 addr_width; ++ u8 dummy_bytes; ++ u8 opcode_nbits; ++ u8 addr_nbits; ++ u8 data_nbits; ++}; ++ ++/* SPI core interface for flash read support */ ++static inline bool spi_flash_read_supported(struct spi_device *spi) ++{ ++ return spi->master->spi_flash_read ? true : false; ++} ++ ++int spi_flash_read(struct spi_device *spi, ++ struct spi_flash_read_message *msg); ++ + /*---------------------------------------------------------------------------*/ + + /* -- cgit v1.2.3