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822 lines
22 KiB
822 lines
22 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* Copyright (C) 2018 Exceet Electronics GmbH |
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* Copyright (C) 2018 Bootlin |
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* |
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* Author: Boris Brezillon <[email protected]> |
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*/ |
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#include <linux/dmaengine.h> |
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#include <linux/pm_runtime.h> |
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#include <linux/spi/spi.h> |
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#include <linux/spi/spi-mem.h> |
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|
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#include "internals.h" |
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|
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#define SPI_MEM_MAX_BUSWIDTH 8 |
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|
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/** |
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* spi_controller_dma_map_mem_op_data() - DMA-map the buffer attached to a |
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* memory operation |
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* @ctlr: the SPI controller requesting this dma_map() |
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* @op: the memory operation containing the buffer to map |
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* @sgt: a pointer to a non-initialized sg_table that will be filled by this |
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* function |
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* |
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* Some controllers might want to do DMA on the data buffer embedded in @op. |
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* This helper prepares everything for you and provides a ready-to-use |
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* sg_table. This function is not intended to be called from spi drivers. |
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* Only SPI controller drivers should use it. |
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* Note that the caller must ensure the memory region pointed by |
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* op->data.buf.{in,out} is DMA-able before calling this function. |
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* |
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* Return: 0 in case of success, a negative error code otherwise. |
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*/ |
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int spi_controller_dma_map_mem_op_data(struct spi_controller *ctlr, |
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const struct spi_mem_op *op, |
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struct sg_table *sgt) |
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{ |
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struct device *dmadev; |
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|
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if (!op->data.nbytes) |
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return -EINVAL; |
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|
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if (op->data.dir == SPI_MEM_DATA_OUT && ctlr->dma_tx) |
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dmadev = ctlr->dma_tx->device->dev; |
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else if (op->data.dir == SPI_MEM_DATA_IN && ctlr->dma_rx) |
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dmadev = ctlr->dma_rx->device->dev; |
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else |
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dmadev = ctlr->dev.parent; |
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|
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if (!dmadev) |
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return -EINVAL; |
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|
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return spi_map_buf(ctlr, dmadev, sgt, op->data.buf.in, op->data.nbytes, |
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op->data.dir == SPI_MEM_DATA_IN ? |
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DMA_FROM_DEVICE : DMA_TO_DEVICE); |
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} |
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EXPORT_SYMBOL_GPL(spi_controller_dma_map_mem_op_data); |
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|
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/** |
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* spi_controller_dma_unmap_mem_op_data() - DMA-unmap the buffer attached to a |
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* memory operation |
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* @ctlr: the SPI controller requesting this dma_unmap() |
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* @op: the memory operation containing the buffer to unmap |
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* @sgt: a pointer to an sg_table previously initialized by |
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* spi_controller_dma_map_mem_op_data() |
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* |
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* Some controllers might want to do DMA on the data buffer embedded in @op. |
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* This helper prepares things so that the CPU can access the |
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* op->data.buf.{in,out} buffer again. |
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* |
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* This function is not intended to be called from SPI drivers. Only SPI |
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* controller drivers should use it. |
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* |
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* This function should be called after the DMA operation has finished and is |
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* only valid if the previous spi_controller_dma_map_mem_op_data() call |
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* returned 0. |
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* |
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* Return: 0 in case of success, a negative error code otherwise. |
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*/ |
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void spi_controller_dma_unmap_mem_op_data(struct spi_controller *ctlr, |
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const struct spi_mem_op *op, |
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struct sg_table *sgt) |
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{ |
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struct device *dmadev; |
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|
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if (!op->data.nbytes) |
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return; |
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if (op->data.dir == SPI_MEM_DATA_OUT && ctlr->dma_tx) |
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dmadev = ctlr->dma_tx->device->dev; |
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else if (op->data.dir == SPI_MEM_DATA_IN && ctlr->dma_rx) |
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dmadev = ctlr->dma_rx->device->dev; |
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else |
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dmadev = ctlr->dev.parent; |
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spi_unmap_buf(ctlr, dmadev, sgt, |
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op->data.dir == SPI_MEM_DATA_IN ? |
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DMA_FROM_DEVICE : DMA_TO_DEVICE); |
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} |
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EXPORT_SYMBOL_GPL(spi_controller_dma_unmap_mem_op_data); |
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|
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static int spi_check_buswidth_req(struct spi_mem *mem, u8 buswidth, bool tx) |
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{ |
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u32 mode = mem->spi->mode; |
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|
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switch (buswidth) { |
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case 1: |
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return 0; |
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|
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case 2: |
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if ((tx && |
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(mode & (SPI_TX_DUAL | SPI_TX_QUAD | SPI_TX_OCTAL))) || |
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(!tx && |
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(mode & (SPI_RX_DUAL | SPI_RX_QUAD | SPI_RX_OCTAL)))) |
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return 0; |
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|
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break; |
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case 4: |
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if ((tx && (mode & (SPI_TX_QUAD | SPI_TX_OCTAL))) || |
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(!tx && (mode & (SPI_RX_QUAD | SPI_RX_OCTAL)))) |
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return 0; |
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|
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break; |
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case 8: |
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if ((tx && (mode & SPI_TX_OCTAL)) || |
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(!tx && (mode & SPI_RX_OCTAL))) |
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return 0; |
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break; |
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default: |
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break; |
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} |
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|
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return -ENOTSUPP; |
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} |
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static bool spi_mem_check_buswidth(struct spi_mem *mem, |
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const struct spi_mem_op *op) |
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{ |
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if (spi_check_buswidth_req(mem, op->cmd.buswidth, true)) |
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return false; |
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|
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if (op->addr.nbytes && |
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spi_check_buswidth_req(mem, op->addr.buswidth, true)) |
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return false; |
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|
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if (op->dummy.nbytes && |
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spi_check_buswidth_req(mem, op->dummy.buswidth, true)) |
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return false; |
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if (op->data.dir != SPI_MEM_NO_DATA && |
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spi_check_buswidth_req(mem, op->data.buswidth, |
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op->data.dir == SPI_MEM_DATA_OUT)) |
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return false; |
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return true; |
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} |
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bool spi_mem_dtr_supports_op(struct spi_mem *mem, |
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const struct spi_mem_op *op) |
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{ |
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if (op->cmd.nbytes != 2) |
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return false; |
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|
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return spi_mem_check_buswidth(mem, op); |
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} |
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EXPORT_SYMBOL_GPL(spi_mem_dtr_supports_op); |
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|
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bool spi_mem_default_supports_op(struct spi_mem *mem, |
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const struct spi_mem_op *op) |
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{ |
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if (op->cmd.dtr || op->addr.dtr || op->dummy.dtr || op->data.dtr) |
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return false; |
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if (op->cmd.nbytes != 1) |
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return false; |
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return spi_mem_check_buswidth(mem, op); |
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} |
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EXPORT_SYMBOL_GPL(spi_mem_default_supports_op); |
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static bool spi_mem_buswidth_is_valid(u8 buswidth) |
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{ |
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if (hweight8(buswidth) > 1 || buswidth > SPI_MEM_MAX_BUSWIDTH) |
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return false; |
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return true; |
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} |
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static int spi_mem_check_op(const struct spi_mem_op *op) |
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{ |
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if (!op->cmd.buswidth || !op->cmd.nbytes) |
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return -EINVAL; |
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|
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if ((op->addr.nbytes && !op->addr.buswidth) || |
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(op->dummy.nbytes && !op->dummy.buswidth) || |
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(op->data.nbytes && !op->data.buswidth)) |
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return -EINVAL; |
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if (!spi_mem_buswidth_is_valid(op->cmd.buswidth) || |
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!spi_mem_buswidth_is_valid(op->addr.buswidth) || |
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!spi_mem_buswidth_is_valid(op->dummy.buswidth) || |
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!spi_mem_buswidth_is_valid(op->data.buswidth)) |
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return -EINVAL; |
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return 0; |
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} |
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static bool spi_mem_internal_supports_op(struct spi_mem *mem, |
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const struct spi_mem_op *op) |
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{ |
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struct spi_controller *ctlr = mem->spi->controller; |
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if (ctlr->mem_ops && ctlr->mem_ops->supports_op) |
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return ctlr->mem_ops->supports_op(mem, op); |
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return spi_mem_default_supports_op(mem, op); |
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} |
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/** |
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* spi_mem_supports_op() - Check if a memory device and the controller it is |
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* connected to support a specific memory operation |
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* @mem: the SPI memory |
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* @op: the memory operation to check |
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* |
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* Some controllers are only supporting Single or Dual IOs, others might only |
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* support specific opcodes, or it can even be that the controller and device |
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* both support Quad IOs but the hardware prevents you from using it because |
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* only 2 IO lines are connected. |
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* |
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* This function checks whether a specific operation is supported. |
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* |
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* Return: true if @op is supported, false otherwise. |
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*/ |
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bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op) |
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{ |
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if (spi_mem_check_op(op)) |
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return false; |
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|
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return spi_mem_internal_supports_op(mem, op); |
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} |
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EXPORT_SYMBOL_GPL(spi_mem_supports_op); |
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|
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static int spi_mem_access_start(struct spi_mem *mem) |
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{ |
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struct spi_controller *ctlr = mem->spi->controller; |
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|
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/* |
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* Flush the message queue before executing our SPI memory |
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* operation to prevent preemption of regular SPI transfers. |
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*/ |
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spi_flush_queue(ctlr); |
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|
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if (ctlr->auto_runtime_pm) { |
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int ret; |
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ret = pm_runtime_get_sync(ctlr->dev.parent); |
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if (ret < 0) { |
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pm_runtime_put_noidle(ctlr->dev.parent); |
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dev_err(&ctlr->dev, "Failed to power device: %d\n", |
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ret); |
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return ret; |
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} |
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} |
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mutex_lock(&ctlr->bus_lock_mutex); |
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mutex_lock(&ctlr->io_mutex); |
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return 0; |
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} |
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static void spi_mem_access_end(struct spi_mem *mem) |
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{ |
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struct spi_controller *ctlr = mem->spi->controller; |
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mutex_unlock(&ctlr->io_mutex); |
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mutex_unlock(&ctlr->bus_lock_mutex); |
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|
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if (ctlr->auto_runtime_pm) |
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pm_runtime_put(ctlr->dev.parent); |
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} |
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/** |
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* spi_mem_exec_op() - Execute a memory operation |
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* @mem: the SPI memory |
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* @op: the memory operation to execute |
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* |
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* Executes a memory operation. |
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* |
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* This function first checks that @op is supported and then tries to execute |
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* it. |
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* |
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* Return: 0 in case of success, a negative error code otherwise. |
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*/ |
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int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) |
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{ |
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unsigned int tmpbufsize, xferpos = 0, totalxferlen = 0; |
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struct spi_controller *ctlr = mem->spi->controller; |
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struct spi_transfer xfers[4] = { }; |
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struct spi_message msg; |
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u8 *tmpbuf; |
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int ret; |
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ret = spi_mem_check_op(op); |
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if (ret) |
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return ret; |
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if (!spi_mem_internal_supports_op(mem, op)) |
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return -ENOTSUPP; |
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if (ctlr->mem_ops && !mem->spi->cs_gpiod) { |
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ret = spi_mem_access_start(mem); |
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if (ret) |
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return ret; |
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ret = ctlr->mem_ops->exec_op(mem, op); |
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spi_mem_access_end(mem); |
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/* |
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* Some controllers only optimize specific paths (typically the |
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* read path) and expect the core to use the regular SPI |
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* interface in other cases. |
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*/ |
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if (!ret || ret != -ENOTSUPP) |
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return ret; |
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} |
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tmpbufsize = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes; |
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|
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/* |
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* Allocate a buffer to transmit the CMD, ADDR cycles with kmalloc() so |
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* we're guaranteed that this buffer is DMA-able, as required by the |
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* SPI layer. |
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*/ |
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tmpbuf = kzalloc(tmpbufsize, GFP_KERNEL | GFP_DMA); |
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if (!tmpbuf) |
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return -ENOMEM; |
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spi_message_init(&msg); |
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tmpbuf[0] = op->cmd.opcode; |
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xfers[xferpos].tx_buf = tmpbuf; |
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xfers[xferpos].len = op->cmd.nbytes; |
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xfers[xferpos].tx_nbits = op->cmd.buswidth; |
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spi_message_add_tail(&xfers[xferpos], &msg); |
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xferpos++; |
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totalxferlen++; |
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|
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if (op->addr.nbytes) { |
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int i; |
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|
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for (i = 0; i < op->addr.nbytes; i++) |
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tmpbuf[i + 1] = op->addr.val >> |
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(8 * (op->addr.nbytes - i - 1)); |
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|
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xfers[xferpos].tx_buf = tmpbuf + 1; |
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xfers[xferpos].len = op->addr.nbytes; |
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xfers[xferpos].tx_nbits = op->addr.buswidth; |
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spi_message_add_tail(&xfers[xferpos], &msg); |
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xferpos++; |
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totalxferlen += op->addr.nbytes; |
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} |
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|
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if (op->dummy.nbytes) { |
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memset(tmpbuf + op->addr.nbytes + 1, 0xff, op->dummy.nbytes); |
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xfers[xferpos].tx_buf = tmpbuf + op->addr.nbytes + 1; |
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xfers[xferpos].len = op->dummy.nbytes; |
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xfers[xferpos].tx_nbits = op->dummy.buswidth; |
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xfers[xferpos].dummy_data = 1; |
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spi_message_add_tail(&xfers[xferpos], &msg); |
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xferpos++; |
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totalxferlen += op->dummy.nbytes; |
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} |
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|
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if (op->data.nbytes) { |
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if (op->data.dir == SPI_MEM_DATA_IN) { |
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xfers[xferpos].rx_buf = op->data.buf.in; |
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xfers[xferpos].rx_nbits = op->data.buswidth; |
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} else { |
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xfers[xferpos].tx_buf = op->data.buf.out; |
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xfers[xferpos].tx_nbits = op->data.buswidth; |
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} |
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|
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xfers[xferpos].len = op->data.nbytes; |
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spi_message_add_tail(&xfers[xferpos], &msg); |
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xferpos++; |
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totalxferlen += op->data.nbytes; |
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} |
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ret = spi_sync(mem->spi, &msg); |
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|
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kfree(tmpbuf); |
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if (ret) |
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return ret; |
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|
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if (msg.actual_length != totalxferlen) |
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return -EIO; |
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|
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(spi_mem_exec_op); |
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|
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/** |
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* spi_mem_get_name() - Return the SPI mem device name to be used by the |
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* upper layer if necessary |
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* @mem: the SPI memory |
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* |
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* This function allows SPI mem users to retrieve the SPI mem device name. |
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* It is useful if the upper layer needs to expose a custom name for |
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* compatibility reasons. |
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* |
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* Return: a string containing the name of the memory device to be used |
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* by the SPI mem user |
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*/ |
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const char *spi_mem_get_name(struct spi_mem *mem) |
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{ |
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return mem->name; |
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} |
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EXPORT_SYMBOL_GPL(spi_mem_get_name); |
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|
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/** |
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* spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to |
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* match controller limitations |
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* @mem: the SPI memory |
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* @op: the operation to adjust |
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* |
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* Some controllers have FIFO limitations and must split a data transfer |
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* operation into multiple ones, others require a specific alignment for |
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* optimized accesses. This function allows SPI mem drivers to split a single |
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* operation into multiple sub-operations when required. |
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* |
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* Return: a negative error code if the controller can't properly adjust @op, |
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* 0 otherwise. Note that @op->data.nbytes will be updated if @op |
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* can't be handled in a single step. |
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*/ |
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int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op) |
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{ |
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struct spi_controller *ctlr = mem->spi->controller; |
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size_t len; |
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|
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if (ctlr->mem_ops && ctlr->mem_ops->adjust_op_size) |
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return ctlr->mem_ops->adjust_op_size(mem, op); |
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|
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if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) { |
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len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes; |
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|
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if (len > spi_max_transfer_size(mem->spi)) |
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return -EINVAL; |
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|
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op->data.nbytes = min3((size_t)op->data.nbytes, |
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spi_max_transfer_size(mem->spi), |
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spi_max_message_size(mem->spi) - |
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len); |
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if (!op->data.nbytes) |
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return -EINVAL; |
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} |
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|
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size); |
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|
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static ssize_t spi_mem_no_dirmap_read(struct spi_mem_dirmap_desc *desc, |
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u64 offs, size_t len, void *buf) |
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{ |
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struct spi_mem_op op = desc->info.op_tmpl; |
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int ret; |
|
|
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op.addr.val = desc->info.offset + offs; |
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op.data.buf.in = buf; |
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op.data.nbytes = len; |
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ret = spi_mem_adjust_op_size(desc->mem, &op); |
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if (ret) |
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return ret; |
|
|
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ret = spi_mem_exec_op(desc->mem, &op); |
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if (ret) |
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return ret; |
|
|
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return op.data.nbytes; |
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} |
|
|
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static ssize_t spi_mem_no_dirmap_write(struct spi_mem_dirmap_desc *desc, |
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u64 offs, size_t len, const void *buf) |
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{ |
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struct spi_mem_op op = desc->info.op_tmpl; |
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int ret; |
|
|
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op.addr.val = desc->info.offset + offs; |
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op.data.buf.out = buf; |
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op.data.nbytes = len; |
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ret = spi_mem_adjust_op_size(desc->mem, &op); |
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if (ret) |
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return ret; |
|
|
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ret = spi_mem_exec_op(desc->mem, &op); |
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if (ret) |
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return ret; |
|
|
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return op.data.nbytes; |
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} |
|
|
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/** |
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* spi_mem_dirmap_create() - Create a direct mapping descriptor |
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* @mem: SPI mem device this direct mapping should be created for |
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* @info: direct mapping information |
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* |
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* This function is creating a direct mapping descriptor which can then be used |
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* to access the memory using spi_mem_dirmap_read() or spi_mem_dirmap_write(). |
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* If the SPI controller driver does not support direct mapping, this function |
|
* falls back to an implementation using spi_mem_exec_op(), so that the caller |
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* doesn't have to bother implementing a fallback on his own. |
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* |
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* Return: a valid pointer in case of success, and ERR_PTR() otherwise. |
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*/ |
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struct spi_mem_dirmap_desc * |
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spi_mem_dirmap_create(struct spi_mem *mem, |
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const struct spi_mem_dirmap_info *info) |
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{ |
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struct spi_controller *ctlr = mem->spi->controller; |
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struct spi_mem_dirmap_desc *desc; |
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int ret = -ENOTSUPP; |
|
|
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/* Make sure the number of address cycles is between 1 and 8 bytes. */ |
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if (!info->op_tmpl.addr.nbytes || info->op_tmpl.addr.nbytes > 8) |
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return ERR_PTR(-EINVAL); |
|
|
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/* data.dir should either be SPI_MEM_DATA_IN or SPI_MEM_DATA_OUT. */ |
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if (info->op_tmpl.data.dir == SPI_MEM_NO_DATA) |
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return ERR_PTR(-EINVAL); |
|
|
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desc = kzalloc(sizeof(*desc), GFP_KERNEL); |
|
if (!desc) |
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return ERR_PTR(-ENOMEM); |
|
|
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desc->mem = mem; |
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desc->info = *info; |
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if (ctlr->mem_ops && ctlr->mem_ops->dirmap_create) |
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ret = ctlr->mem_ops->dirmap_create(desc); |
|
|
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if (ret) { |
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desc->nodirmap = true; |
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if (!spi_mem_supports_op(desc->mem, &desc->info.op_tmpl)) |
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ret = -ENOTSUPP; |
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else |
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ret = 0; |
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} |
|
|
|
if (ret) { |
|
kfree(desc); |
|
return ERR_PTR(ret); |
|
} |
|
|
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return desc; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_mem_dirmap_create); |
|
|
|
/** |
|
* spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor |
|
* @desc: the direct mapping descriptor to destroy |
|
* |
|
* This function destroys a direct mapping descriptor previously created by |
|
* spi_mem_dirmap_create(). |
|
*/ |
|
void spi_mem_dirmap_destroy(struct spi_mem_dirmap_desc *desc) |
|
{ |
|
struct spi_controller *ctlr = desc->mem->spi->controller; |
|
|
|
if (!desc->nodirmap && ctlr->mem_ops && ctlr->mem_ops->dirmap_destroy) |
|
ctlr->mem_ops->dirmap_destroy(desc); |
|
|
|
kfree(desc); |
|
} |
|
EXPORT_SYMBOL_GPL(spi_mem_dirmap_destroy); |
|
|
|
static void devm_spi_mem_dirmap_release(struct device *dev, void *res) |
|
{ |
|
struct spi_mem_dirmap_desc *desc = *(struct spi_mem_dirmap_desc **)res; |
|
|
|
spi_mem_dirmap_destroy(desc); |
|
} |
|
|
|
/** |
|
* devm_spi_mem_dirmap_create() - Create a direct mapping descriptor and attach |
|
* it to a device |
|
* @dev: device the dirmap desc will be attached to |
|
* @mem: SPI mem device this direct mapping should be created for |
|
* @info: direct mapping information |
|
* |
|
* devm_ variant of the spi_mem_dirmap_create() function. See |
|
* spi_mem_dirmap_create() for more details. |
|
* |
|
* Return: a valid pointer in case of success, and ERR_PTR() otherwise. |
|
*/ |
|
struct spi_mem_dirmap_desc * |
|
devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem, |
|
const struct spi_mem_dirmap_info *info) |
|
{ |
|
struct spi_mem_dirmap_desc **ptr, *desc; |
|
|
|
ptr = devres_alloc(devm_spi_mem_dirmap_release, sizeof(*ptr), |
|
GFP_KERNEL); |
|
if (!ptr) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
desc = spi_mem_dirmap_create(mem, info); |
|
if (IS_ERR(desc)) { |
|
devres_free(ptr); |
|
} else { |
|
*ptr = desc; |
|
devres_add(dev, ptr); |
|
} |
|
|
|
return desc; |
|
} |
|
EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_create); |
|
|
|
static int devm_spi_mem_dirmap_match(struct device *dev, void *res, void *data) |
|
{ |
|
struct spi_mem_dirmap_desc **ptr = res; |
|
|
|
if (WARN_ON(!ptr || !*ptr)) |
|
return 0; |
|
|
|
return *ptr == data; |
|
} |
|
|
|
/** |
|
* devm_spi_mem_dirmap_destroy() - Destroy a direct mapping descriptor attached |
|
* to a device |
|
* @dev: device the dirmap desc is attached to |
|
* @desc: the direct mapping descriptor to destroy |
|
* |
|
* devm_ variant of the spi_mem_dirmap_destroy() function. See |
|
* spi_mem_dirmap_destroy() for more details. |
|
*/ |
|
void devm_spi_mem_dirmap_destroy(struct device *dev, |
|
struct spi_mem_dirmap_desc *desc) |
|
{ |
|
devres_release(dev, devm_spi_mem_dirmap_release, |
|
devm_spi_mem_dirmap_match, desc); |
|
} |
|
EXPORT_SYMBOL_GPL(devm_spi_mem_dirmap_destroy); |
|
|
|
/** |
|
* spi_mem_dirmap_read() - Read data through a direct mapping |
|
* @desc: direct mapping descriptor |
|
* @offs: offset to start reading from. Note that this is not an absolute |
|
* offset, but the offset within the direct mapping which already has |
|
* its own offset |
|
* @len: length in bytes |
|
* @buf: destination buffer. This buffer must be DMA-able |
|
* |
|
* This function reads data from a memory device using a direct mapping |
|
* previously instantiated with spi_mem_dirmap_create(). |
|
* |
|
* Return: the amount of data read from the memory device or a negative error |
|
* code. Note that the returned size might be smaller than @len, and the caller |
|
* is responsible for calling spi_mem_dirmap_read() again when that happens. |
|
*/ |
|
ssize_t spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc, |
|
u64 offs, size_t len, void *buf) |
|
{ |
|
struct spi_controller *ctlr = desc->mem->spi->controller; |
|
ssize_t ret; |
|
|
|
if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_IN) |
|
return -EINVAL; |
|
|
|
if (!len) |
|
return 0; |
|
|
|
if (desc->nodirmap) { |
|
ret = spi_mem_no_dirmap_read(desc, offs, len, buf); |
|
} else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_read) { |
|
ret = spi_mem_access_start(desc->mem); |
|
if (ret) |
|
return ret; |
|
|
|
ret = ctlr->mem_ops->dirmap_read(desc, offs, len, buf); |
|
|
|
spi_mem_access_end(desc->mem); |
|
} else { |
|
ret = -ENOTSUPP; |
|
} |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_mem_dirmap_read); |
|
|
|
/** |
|
* spi_mem_dirmap_write() - Write data through a direct mapping |
|
* @desc: direct mapping descriptor |
|
* @offs: offset to start writing from. Note that this is not an absolute |
|
* offset, but the offset within the direct mapping which already has |
|
* its own offset |
|
* @len: length in bytes |
|
* @buf: source buffer. This buffer must be DMA-able |
|
* |
|
* This function writes data to a memory device using a direct mapping |
|
* previously instantiated with spi_mem_dirmap_create(). |
|
* |
|
* Return: the amount of data written to the memory device or a negative error |
|
* code. Note that the returned size might be smaller than @len, and the caller |
|
* is responsible for calling spi_mem_dirmap_write() again when that happens. |
|
*/ |
|
ssize_t spi_mem_dirmap_write(struct spi_mem_dirmap_desc *desc, |
|
u64 offs, size_t len, const void *buf) |
|
{ |
|
struct spi_controller *ctlr = desc->mem->spi->controller; |
|
ssize_t ret; |
|
|
|
if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_OUT) |
|
return -EINVAL; |
|
|
|
if (!len) |
|
return 0; |
|
|
|
if (desc->nodirmap) { |
|
ret = spi_mem_no_dirmap_write(desc, offs, len, buf); |
|
} else if (ctlr->mem_ops && ctlr->mem_ops->dirmap_write) { |
|
ret = spi_mem_access_start(desc->mem); |
|
if (ret) |
|
return ret; |
|
|
|
ret = ctlr->mem_ops->dirmap_write(desc, offs, len, buf); |
|
|
|
spi_mem_access_end(desc->mem); |
|
} else { |
|
ret = -ENOTSUPP; |
|
} |
|
|
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(spi_mem_dirmap_write); |
|
|
|
static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv) |
|
{ |
|
return container_of(drv, struct spi_mem_driver, spidrv.driver); |
|
} |
|
|
|
static int spi_mem_probe(struct spi_device *spi) |
|
{ |
|
struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver); |
|
struct spi_controller *ctlr = spi->controller; |
|
struct spi_mem *mem; |
|
|
|
mem = devm_kzalloc(&spi->dev, sizeof(*mem), GFP_KERNEL); |
|
if (!mem) |
|
return -ENOMEM; |
|
|
|
mem->spi = spi; |
|
|
|
if (ctlr->mem_ops && ctlr->mem_ops->get_name) |
|
mem->name = ctlr->mem_ops->get_name(mem); |
|
else |
|
mem->name = dev_name(&spi->dev); |
|
|
|
if (IS_ERR_OR_NULL(mem->name)) |
|
return PTR_ERR_OR_ZERO(mem->name); |
|
|
|
spi_set_drvdata(spi, mem); |
|
|
|
return memdrv->probe(mem); |
|
} |
|
|
|
static int spi_mem_remove(struct spi_device *spi) |
|
{ |
|
struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver); |
|
struct spi_mem *mem = spi_get_drvdata(spi); |
|
|
|
if (memdrv->remove) |
|
return memdrv->remove(mem); |
|
|
|
return 0; |
|
} |
|
|
|
static void spi_mem_shutdown(struct spi_device *spi) |
|
{ |
|
struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver); |
|
struct spi_mem *mem = spi_get_drvdata(spi); |
|
|
|
if (memdrv->shutdown) |
|
memdrv->shutdown(mem); |
|
} |
|
|
|
/** |
|
* spi_mem_driver_register_with_owner() - Register a SPI memory driver |
|
* @memdrv: the SPI memory driver to register |
|
* @owner: the owner of this driver |
|
* |
|
* Registers a SPI memory driver. |
|
* |
|
* Return: 0 in case of success, a negative error core otherwise. |
|
*/ |
|
|
|
int spi_mem_driver_register_with_owner(struct spi_mem_driver *memdrv, |
|
struct module *owner) |
|
{ |
|
memdrv->spidrv.probe = spi_mem_probe; |
|
memdrv->spidrv.remove = spi_mem_remove; |
|
memdrv->spidrv.shutdown = spi_mem_shutdown; |
|
|
|
return __spi_register_driver(owner, &memdrv->spidrv); |
|
} |
|
EXPORT_SYMBOL_GPL(spi_mem_driver_register_with_owner); |
|
|
|
/** |
|
* spi_mem_driver_unregister_with_owner() - Unregister a SPI memory driver |
|
* @memdrv: the SPI memory driver to unregister |
|
* |
|
* Unregisters a SPI memory driver. |
|
*/ |
|
void spi_mem_driver_unregister(struct spi_mem_driver *memdrv) |
|
{ |
|
spi_unregister_driver(&memdrv->spidrv); |
|
} |
|
EXPORT_SYMBOL_GPL(spi_mem_driver_unregister);
|
|
|