From e7edd2cf4c7d06c6ef3e2030f66eeefa5150f0ff Mon Sep 17 00:00:00 2001 From: Chuanhong Guo Date: Thu, 24 Sep 2020 23:27:28 +0800 Subject: spi: spi-mtk-nor: make use of full capability of prg mode "program" mode on this controller can trigger up to 56 bits of data shifting. During the operation, data in PRGDATA[0-5] will be shifted out from MOSI, and data from MISO will be continuously filling SHREG[0-9]. Currently this mode is used to implement transfer_one_message for 6-byte full-duplex transfer, but it can execute a transfer for up-to 7 bytes as long as the last byte is read only. transfer_one_message is expected to perform full-duplex transfer, instead of transfer with specific format. mtk_nor_spi_mem_prg is added here to use this extra byte. Newer version of this controller can trigger longer data shifting with shift bytes more than PRGDATA_MAX + SHREG_MAX. This patch is implemented with that in mind and it checks against both SHREG_MAX and PRG_CNT_MAX for future support of new controllers. Signed-off-by: Chuanhong Guo Link: https://lore.kernel.org/r/20200924152730.733243-2-gch981213@gmail.com Signed-off-by: Mark Brown --- drivers/spi/spi-mtk-nor.c | 82 +++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 80 insertions(+), 2 deletions(-) (limited to 'drivers/spi') diff --git a/drivers/spi/spi-mtk-nor.c b/drivers/spi/spi-mtk-nor.c index 62f5ff277988..a0087a5e869b 100644 --- a/drivers/spi/spi-mtk-nor.c +++ b/drivers/spi/spi-mtk-nor.c @@ -27,6 +27,7 @@ #define MTK_NOR_CMD_MASK GENMASK(5, 0) #define MTK_NOR_REG_PRG_CNT 0x04 +#define MTK_NOR_PRG_CNT_MAX 56 #define MTK_NOR_REG_RDATA 0x0c #define MTK_NOR_REG_RADR0 0x10 @@ -404,6 +405,83 @@ static int mtk_nor_pp_unbuffered(struct mtk_nor *sp, return mtk_nor_cmd_exec(sp, MTK_NOR_CMD_WRITE, 6 * BITS_PER_BYTE); } +static int mtk_nor_spi_mem_prg(struct mtk_nor *sp, const struct spi_mem_op *op) +{ + int rx_len = 0; + int reg_offset = MTK_NOR_REG_PRGDATA_MAX; + int tx_len, prg_len; + int i, ret; + void __iomem *reg; + u8 bufbyte; + + tx_len = op->cmd.nbytes + op->addr.nbytes; + + // count dummy bytes only if we need to write data after it + if (op->data.dir == SPI_MEM_DATA_OUT) + tx_len += op->dummy.nbytes + op->data.nbytes; + else if (op->data.dir == SPI_MEM_DATA_IN) + rx_len = op->data.nbytes; + + prg_len = op->cmd.nbytes + op->addr.nbytes + op->dummy.nbytes + + op->data.nbytes; + + // an invalid op may reach here if the caller calls exec_op without + // adjust_op_size. return -EINVAL instead of -ENOTSUPP so that + // spi-mem won't try this op again with generic spi transfers. + if ((tx_len > MTK_NOR_REG_PRGDATA_MAX + 1) || + (rx_len > MTK_NOR_REG_SHIFT_MAX + 1) || + (prg_len > MTK_NOR_PRG_CNT_MAX / 8)) + return -EINVAL; + + // fill tx data + for (i = op->cmd.nbytes; i > 0; i--, reg_offset--) { + reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset); + bufbyte = (op->cmd.opcode >> ((i - 1) * BITS_PER_BYTE)) & 0xff; + writeb(bufbyte, reg); + } + + for (i = op->addr.nbytes; i > 0; i--, reg_offset--) { + reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset); + bufbyte = (op->addr.val >> ((i - 1) * BITS_PER_BYTE)) & 0xff; + writeb(bufbyte, reg); + } + + if (op->data.dir == SPI_MEM_DATA_OUT) { + for (i = 0; i < op->dummy.nbytes; i++, reg_offset--) { + reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset); + writeb(0, reg); + } + + for (i = 0; i < op->data.nbytes; i++, reg_offset--) { + reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset); + writeb(((const u8 *)(op->data.buf.out))[i], reg); + } + } + + for (; reg_offset >= 0; reg_offset--) { + reg = sp->base + MTK_NOR_REG_PRGDATA(reg_offset); + writeb(0, reg); + } + + // trigger op + writel(prg_len * BITS_PER_BYTE, sp->base + MTK_NOR_REG_PRG_CNT); + ret = mtk_nor_cmd_exec(sp, MTK_NOR_CMD_PROGRAM, + prg_len * BITS_PER_BYTE); + if (ret) + return ret; + + // fetch read data + reg_offset = 0; + if (op->data.dir == SPI_MEM_DATA_IN) { + for (i = op->data.nbytes - 1; i >= 0; i--, reg_offset++) { + reg = sp->base + MTK_NOR_REG_SHIFT(reg_offset); + ((u8 *)(op->data.buf.in))[i] = readb(reg); + } + } + + return 0; +} + static int mtk_nor_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) { struct mtk_nor *sp = spi_controller_get_devdata(mem->spi->master); @@ -411,7 +489,7 @@ static int mtk_nor_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) if ((op->data.nbytes == 0) || ((op->addr.nbytes != 3) && (op->addr.nbytes != 4))) - return -ENOTSUPP; + return mtk_nor_spi_mem_prg(sp, op); if (op->data.dir == SPI_MEM_DATA_OUT) { mtk_nor_set_addr(sp, op); @@ -441,7 +519,7 @@ static int mtk_nor_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) } } - return -ENOTSUPP; + return mtk_nor_spi_mem_prg(sp, op); } static int mtk_nor_setup(struct spi_device *spi) -- cgit v1.2.3