[PATCH v4 2/2] mtd: spi-nor: add rockchip serial flash controller driver

Shawn Lin shawn.lin at rock-chips.com
Mon Jan 16 17:31:38 PST 2017


Hi Cyrille,

On 2017/1/16 19:10, Cyrille Pitchen wrote:
> Hi Shawn,
>
> Le 15/12/2016 à 10:27, Shawn Lin a écrit :
>> Add rockchip serial flash controller driver
>>
>> Signed-off-by: Shawn Lin <shawn.lin at rock-chips.com>
>>
>> ---
>>
>> Changes in v4:
>> - simplify the code of get_if_type
>> - use dma_dir to simplify the code
>> - simplify the rockchip_sfc_do_rd_wr
>> - some minor improvements
>> - add reset controller when doing resume
>>
>> Changes in v3:
>> - use io{read32,write32}_rep to simplify the corner cases
>> - remove more unnecessary bit definitions
>> - some minor comment fixes and improvement
>> - fix wrong unregister function
>> - unify more code
>> - use nor to avoid constantly replicating the whole
>>   sfc->flash[sfc->num_chip].nor
>> - add email for MODULE_AUTHOR
>> - remove #if 1 --- #endif
>> - extract DMA code to imporve the code structure
>> - reset all when failing to do dma
>> - pass sfc to get_if_type
>> - rename sfc-no-dma to sfc-no-DMA
>>
>> Changes in v2:
>> - fix typos
>> - add some comment for buffer and others operations
>> - rename SFC_MAX_CHIP_NUM to MAX_CHIPSELECT_NUM
>> - use u8 for cs
>> - return -EINVAL for default case of get_if_type
>> - use readl_poll_*() to check timeout cases
>> - simplify and clarify some condition checks
>> - rework the bitshifts to simplify the code
>> - define SFC_CMD_DUMMY(x)
>> - fix ummap for dma read path and finish all the
>>   cache maintenance.
>> - rename to rockchip_sfc_chip_priv and embed struct spi_nor
>>   in it.
>> - add MODULE_AUTHOR
>> - add runtime PM and general PM support.
>> - Thanks for Marek's comments. Link:
>>   http://lists.infradead.org/pipermail/linux-mtd/2016-November/070321.html
>>
>>  MAINTAINERS                        |   8 +
>>  drivers/mtd/spi-nor/Kconfig        |   7 +
>>  drivers/mtd/spi-nor/Makefile       |   1 +
>>  drivers/mtd/spi-nor/rockchip-sfc.c | 872 +++++++++++++++++++++++++++++++++++++
>>  4 files changed, 888 insertions(+)
>>  create mode 100644 drivers/mtd/spi-nor/rockchip-sfc.c
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 1cd38a7..eb7e06d 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -10266,6 +10266,14 @@ L:	linux-serial at vger.kernel.org
>>  S:	Odd Fixes
>>  F:	drivers/tty/serial/rp2.*
>>
>> +ROCKCHIP SERIAL FLASH CONTROLLER DRIVER
>> +M:	Shawn Lin <shawn.lin at rock-chips.com>
>> +L:	linux-mtd at lists.infradead.org
>> +L:	linux-rockchip at lists.infradead.org
>> +S:	Maintained
>> +F:	Documentation/devicetree/bindings/mtd/rockchip-sfc.txt
>> +F:	drivers/mtd/spi-nor/rockchip-sfc.c
>> +
>>  ROSE NETWORK LAYER
>>  M:	Ralf Baechle <ralf at linux-mips.org>
>>  L:	linux-hams at vger.kernel.org
>> diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
>> index 4a682ee..bf783a8 100644
>> --- a/drivers/mtd/spi-nor/Kconfig
>> +++ b/drivers/mtd/spi-nor/Kconfig
>> @@ -76,4 +76,11 @@ config SPI_NXP_SPIFI
>>  	  Flash. Enable this option if you have a device with a SPIFI
>>  	  controller and want to access the Flash as a mtd device.
>>
>> +config SPI_ROCKCHIP_SFC
>> +	tristate "Rockchip Serial Flash Controller(SFC)"
>> +	depends on ARCH_ROCKCHIP || COMPILE_TEST
>> +	depends on HAS_IOMEM && HAS_DMA
>> +	help
>> +	  This enables support for rockchip serial flash controller.
>> +
>>  endif # MTD_SPI_NOR
>> diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
>> index 121695e..364d4c6 100644
>> --- a/drivers/mtd/spi-nor/Makefile
>> +++ b/drivers/mtd/spi-nor/Makefile
>> @@ -5,3 +5,4 @@ obj-$(CONFIG_SPI_FSL_QUADSPI)	+= fsl-quadspi.o
>>  obj-$(CONFIG_SPI_HISI_SFC)	+= hisi-sfc.o
>>  obj-$(CONFIG_MTD_MT81xx_NOR)    += mtk-quadspi.o
>>  obj-$(CONFIG_SPI_NXP_SPIFI)	+= nxp-spifi.o
>> +obj-$(CONFIG_SPI_ROCKCHIP_SFC)	+= rockchip-sfc.o
>> diff --git a/drivers/mtd/spi-nor/rockchip-sfc.c b/drivers/mtd/spi-nor/rockchip-sfc.c
>> new file mode 100644
>> index 0000000..102c08f
>> --- /dev/null
>> +++ b/drivers/mtd/spi-nor/rockchip-sfc.c
>> @@ -0,0 +1,872 @@
>> +/*
>> + * Rockchip Serial Flash Controller Driver
>> + *
>> + * Copyright (c) 2016, Rockchip Inc.
>> + * Author: Shawn Lin <shawn.lin at rock-chips.com>
>> + *
>> + * 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.
>> + *
>> + * You should have received a copy of the GNU General Public License
>> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
>> + */
>> +#include <linux/bitops.h>
>> +#include <linux/clk.h>
>> +#include <linux/completion.h>
>> +#include <linux/dma-mapping.h>
>> +#include <linux/iopoll.h>
>> +#include <linux/module.h>
>> +#include <linux/mtd/mtd.h>
>> +#include <linux/mtd/spi-nor.h>
>> +#include <linux/of.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pm_runtime.h>
>> +#include <linux/slab.h>
>> +
>> +/* System control */
>> +#define SFC_CTRL			0x0
>> +#define  SFC_CTRL_COMMON_BITS_1		0x0
>> +#define  SFC_CTRL_COMMON_BITS_2		0x1
>> +#define  SFC_CTRL_COMMON_BITS_4		0x2
>> +#define  SFC_CTRL_DATA_BITS_SHIFT	12
>> +#define  SFC_CTRL_ADDR_BITS_SHIFT	10
>> +#define  SFC_CTRL_CMD_BITS_SHIFT	8
>> +#define  SFC_CTRL_PHASE_SEL_NEGETIVE	BIT(1)
>> +
>> +/* Interrupt mask */
>> +#define SFC_IMR				0x4
>> +#define  SFC_IMR_RX_FULL		BIT(0)
>> +#define  SFC_IMR_RX_UFLOW		BIT(1)
>> +#define  SFC_IMR_TX_OFLOW		BIT(2)
>> +#define  SFC_IMR_TX_EMPTY		BIT(3)
>> +#define  SFC_IMR_TRAN_FINISH		BIT(4)
>> +#define  SFC_IMR_BUS_ERR		BIT(5)
>> +#define  SFC_IMR_NSPI_ERR		BIT(6)
>> +#define  SFC_IMR_DMA			BIT(7)
>> +/* Interrupt clear */
>> +#define SFC_ICLR			0x8
>> +#define  SFC_ICLR_RX_FULL		BIT(0)
>> +#define  SFC_ICLR_RX_UFLOW		BIT(1)
>> +#define  SFC_ICLR_TX_OFLOW		BIT(2)
>> +#define  SFC_ICLR_TX_EMPTY		BIT(3)
>> +#define  SFC_ICLR_TRAN_FINISH		BIT(4)
>> +#define  SFC_ICLR_BUS_ERR		BIT(5)
>> +#define  SFC_ICLR_NSPI_ERR		BIT(6)
>> +#define  SFC_ICLR_DMA			BIT(7)
>> +/* FIFO threshold level */
>> +#define SFC_FTLR			0xc
>> +#define  SFC_FTLR_TX_SHIFT		0
>> +#define  SFC_FTLR_TX_MASK		0x1f
>> +#define  SFC_FTLR_RX_SHIFT		8
>> +#define  SFC_FTLR_RX_MASK		0x1f
>> +/* Reset FSM and FIFO */
>> +#define SFC_RCVR			0x10
>> +#define  SFC_RCVR_RESET			BIT(0)
>> +/* Enhanced mode */
>> +#define SFC_AX				0x14
>> +/* Address Bit number */
>> +#define SFC_ABIT			0x18
>> +/* Interrupt status */
>> +#define SFC_ISR				0x1c
>> +#define  SFC_ISR_RX_FULL_SHIFT		BIT(0)
>> +#define  SFC_ISR_RX_UFLOW_SHIFT		BIT(1)
>> +#define  SFC_ISR_TX_OFLOW_SHIFT		BIT(2)
>> +#define  SFC_ISR_TX_EMPTY_SHIFT		BIT(3)
>> +#define  SFC_ISR_TX_FINISH_SHIFT	BIT(4)
>> +#define  SFC_ISR_BUS_ERR_SHIFT		BIT(5)
>> +#define  SFC_ISR_NSPI_ERR_SHIFT		BIT(6)
>> +#define  SFC_ISR_DMA_SHIFT		BIT(7)
>> +/* FIFO status */
>> +#define SFC_FSR				0x20
>> +#define  SFC_FSR_TX_IS_FULL		BIT(0)
>> +#define  SFC_FSR_TX_IS_EMPTY		BIT(1)
>> +#define  SFC_FSR_RX_IS_EMPTY		BIT(2)
>> +#define  SFC_FSR_RX_IS_FULL		BIT(3)
>> +/* FSM status */
>> +#define SFC_SR				0x24
>> +#define  SFC_SR_IS_IDLE			0x0
>> +#define  SFC_SR_IS_BUSY			0x1
>> +/* Raw interrupt status */
>> +#define SFC_RISR			0x28
>> +#define  SFC_RISR_RX_FULL		BIT(0)
>> +#define  SFC_RISR_RX_UNDERFLOW		BIT(1)
>> +#define  SFC_RISR_TX_OVERFLOW		BIT(2)
>> +#define  SFC_RISR_TX_EMPTY		BIT(3)
>> +#define  SFC_RISR_TRAN_FINISH		BIT(4)
>> +#define  SFC_RISR_BUS_ERR		BIT(5)
>> +#define  SFC_RISR_NSPI_ERR		BIT(6)
>> +#define  SFC_RISR_DMA			BIT(7)
>> +/* Master trigger */
>> +#define SFC_DMA_TRIGGER			0x80
>> +/* Src or Dst addr for master */
>> +#define SFC_DMA_ADDR			0x84
>> +/* Command */
>> +#define SFC_CMD				0x100
>> +#define  SFC_CMD_IDX_SHIFT		0
>> +#define  SFC_CMD_DUMMY_SHIFT		8
>> +#define  SFC_CMD_DIR_RD			0
>> +#define  SFC_CMD_DIR_WR			1
>> +#define  SFC_CMD_DIR_SHIFT		12
>> +#define  SFC_CMD_ADDR_ZERO		(0x0 << 14)
>> +#define  SFC_CMD_ADDR_24BITS		(0x1 << 14)
>> +#define  SFC_CMD_ADDR_32BITS		(0x2 << 14)
>> +#define  SFC_CMD_ADDR_FRS		(0x3 << 14)
>> +#define  SFC_CMD_TRAN_BYTES_SHIFT	16
>> +#define  SFC_CMD_CS_SHIFT		30
>> +/* Address */
>> +#define SFC_ADDR			0x104
>> +/* Data */
>> +#define SFC_DATA			0x108
>> +
>> +#define SFC_MAX_CHIPSELECT_NUM		4
>> +#define SFC_DMA_MAX_LEN			0x4000
>> +#define SFC_CMD_DUMMY(x) \
>> +	((x) << SFC_CMD_DUMMY_SHIFT)
>> +
>> +enum rockchip_sfc_iftype {
>> +	IF_TYPE_STD,
>> +	IF_TYPE_DUAL,
>> +	IF_TYPE_QUAD,
>> +};
>> +
>> +struct rockchip_sfc;
>> +struct rockchip_sfc_chip_priv {
>> +	u8 cs;
>> +	u32 clk_rate;
>> +	struct spi_nor nor;
>> +	struct rockchip_sfc *sfc;
>> +};
>> +
>> +struct rockchip_sfc {
>> +	struct device *dev;
>> +	struct mutex lock;
>> +	void __iomem *regbase;
>> +	struct clk *hclk;
>> +	struct clk *clk;
>> +	/* virtual mapped addr for dma_buffer */
>> +	void *buffer;
>> +	dma_addr_t dma_buffer;
>> +	struct completion cp;
>> +	struct rockchip_sfc_chip_priv flash[SFC_MAX_CHIPSELECT_NUM];
>> +	u32 num_chip;
>> +	bool use_dma;
>> +	/* use negative edge of hclk to latch data */
>> +	bool negative_edge;
>> +};
>> +
>> +static int get_if_type(struct rockchip_sfc *sfc, enum read_mode flash_read)
>> +{
>> +	if (flash_read == SPI_NOR_DUAL)
>> +		return IF_TYPE_DUAL;
>> +	else if (flash_read == SPI_NOR_QUAD)
>> +		return IF_TYPE_QUAD;
>> +	else if (flash_read == SPI_NOR_NORMAL ||
>> +		 flash_read == SPI_NOR_FAST)
>> +		return IF_TYPE_STD;
>> +
>> +	dev_err(sfc->dev, "unsupported SPI read mode\n");
>> +	return -EINVAL;
>> +}
>> +
>> +static int rockchip_sfc_reset(struct rockchip_sfc *sfc)
>> +{
>> +	int err;
>> +	u32 status;
>> +
>> +	writel_relaxed(SFC_RCVR_RESET, sfc->regbase + SFC_RCVR);
>> +
>> +	err = readl_poll_timeout(sfc->regbase + SFC_RCVR, status,
>> +				 !(status & SFC_RCVR_RESET), 20,
>> +				 jiffies_to_usecs(HZ));
>> +	if (err)
>> +		dev_err(sfc->dev, "SFC reset never finished\n");
>> +
>> +	/* Still need to clear the masked interrupt from RISR */
>> +	writel_relaxed(SFC_ICLR_RX_FULL | SFC_ICLR_RX_UFLOW |
>> +		       SFC_ICLR_TX_OFLOW | SFC_ICLR_TX_EMPTY |
>> +		       SFC_ICLR_TRAN_FINISH | SFC_ICLR_BUS_ERR |
>> +		       SFC_ICLR_NSPI_ERR | SFC_ICLR_DMA,
>> +		       sfc->regbase + SFC_ICLR);
>> +	return err;
>> +}
>> +
>> +static int rockchip_sfc_init(struct rockchip_sfc *sfc)
>> +{
>> +	int err;
>> +
>> +	err = rockchip_sfc_reset(sfc);
>> +	if (err)
>> +		return err;
>> +
>> +	/* Mask all eight interrupts */
>> +	writel_relaxed(0xff, sfc->regbase + SFC_IMR);
>> +
>> +	/*
>> +	 * Phase configure for sfc to latch data by using
>> +	 * ahb clock, and this configuration should be Soc
>> +	 * specific.
>> +	 */
>> +	if (sfc->negative_edge)
>> +		writel_relaxed(SFC_CTRL_PHASE_SEL_NEGETIVE,
>> +			       sfc->regbase + SFC_CTRL);
>> +	else
>> +		writel_relaxed(0, sfc->regbase + SFC_CTRL);
>> +
>> +	return 0;
>> +}
>> +
>> +static int rockchip_sfc_prep(struct spi_nor *nor, enum spi_nor_ops ops)
>> +{
>> +	struct rockchip_sfc_chip_priv *priv = nor->priv;
>> +	struct rockchip_sfc *sfc = priv->sfc;
>> +	int ret;
>> +
>> +	mutex_lock(&sfc->lock);
>> +	pm_runtime_get_sync(sfc->dev);
>> +
>> +	ret = clk_set_rate(sfc->clk, priv->clk_rate);
>> +	if (ret)
>> +		goto out;
>> +
>> +	ret = clk_prepare_enable(sfc->clk);
>> +	if (ret)
>> +		goto out;
>> +
>> +	return 0;
>> +
>> +out:
>> +	mutex_unlock(&sfc->lock);
>> +	return ret;
>> +}
>> +
>> +static void rockchip_sfc_unprep(struct spi_nor *nor, enum spi_nor_ops ops)
>> +{
>> +	struct rockchip_sfc_chip_priv *priv = nor->priv;
>> +	struct rockchip_sfc *sfc = priv->sfc;
>> +
>> +	clk_disable_unprepare(sfc->clk);
>> +	mutex_unlock(&sfc->lock);
>> +	pm_runtime_mark_last_busy(sfc->dev);
>> +	pm_runtime_put_autosuspend(sfc->dev);
>> +}
>> +
>> +static int rockchip_sfc_wait_op_finish(struct rockchip_sfc *sfc)
>> +{
>> +	int err;
>> +	u32 status;
>> +
>> +	/*
>> +	 * Note: tx and rx share the same fifo, so the rx's water level
>> +	 * is the same as rx's, which means this function could be reused
>> +	 * for checking the read operations as well.
>> +	 */
>> +	err = readl_poll_timeout(sfc->regbase + SFC_FSR, status,
>> +				 status & SFC_FSR_TX_IS_EMPTY,
>> +				 20, jiffies_to_usecs(2 * HZ));
>> +	if (err)
>> +		dev_err(sfc->dev, "SFC fifo never empty\n");
>> +
>> +	return err;
>> +}
>> +
>> +static int rockchip_sfc_op_reg(struct spi_nor *nor,
>> +				u8 opcode, int len, u8 optype)
>> +{
>> +	struct rockchip_sfc_chip_priv *priv = nor->priv;
>> +	struct rockchip_sfc *sfc = priv->sfc;
>> +	u32 reg;
>> +	bool tx_no_empty, rx_no_empty, is_busy;
>> +	int err;
>> +
>> +	reg = readl_relaxed(sfc->regbase + SFC_FSR);
>> +	tx_no_empty = !(reg & SFC_FSR_TX_IS_EMPTY);
>> +	rx_no_empty = !(reg & SFC_FSR_RX_IS_EMPTY);
>> +
>> +	is_busy = readl_relaxed(sfc->regbase + SFC_SR);
>> +
>> +	if (tx_no_empty || rx_no_empty || is_busy) {
>> +		err = rockchip_sfc_reset(sfc);
>> +		if (err)
>> +			return err;
>> +	}
>> +
>> +	reg = opcode << SFC_CMD_IDX_SHIFT;
>> +	reg |= len << SFC_CMD_TRAN_BYTES_SHIFT;
>> +	reg |= priv->cs << SFC_CMD_CS_SHIFT;
>> +	reg |= optype << SFC_CMD_DIR_SHIFT;
>> +
>> +	writel_relaxed(reg, sfc->regbase + SFC_CMD);
>> +
>> +	return rockchip_sfc_wait_op_finish(sfc);
>> +}
>> +
>> +static void rockchip_sfc_read_fifo(struct rockchip_sfc *sfc, u8 *buf, int len)
>> +{
>> +	u32 tmp, i;
>> +	int total_len = len;
>> +
>> +	/* 32-bit access only */
>> +	if (len >= 4 && !((u32)buf & 0x03)) {
>> +		ioread32_rep(sfc->regbase + SFC_DATA, buf, len >> 2);
>> +		len %= 4;
>> +		buf += total_len - len;
>> +	}
>> +
>> +	/* read the rest bytes */
>> +	for (i = 0; i < len; i++) {
>> +		if (!(i & 0x03))
>> +			tmp = readl_relaxed(sfc->regbase + SFC_DATA);
>> +		buf[i] = (tmp >> ((i & 0x03) * 8)) & 0xff;
>> +	}
>> +}
>> +
>> +static int rockchip_sfc_read_reg(struct spi_nor *nor, u8 opcode,
>> +				 u8 *buf, int len)
>> +{
>> +	struct rockchip_sfc_chip_priv *priv = nor->priv;
>> +	struct rockchip_sfc *sfc = priv->sfc;
>> +	int ret;
>> +
>> +	ret = rockchip_sfc_op_reg(nor, opcode, len, SFC_CMD_DIR_RD);
>> +	if (ret)
>> +		return ret;
>> +
>> +	rockchip_sfc_read_fifo(sfc, buf, len);
>> +
>> +	return 0;
>> +}
>> +
>> +static int rockchip_sfc_write_reg(struct spi_nor *nor, u8 opcode,
>> +				  u8 *buf, int len)
>> +{
>> +	struct rockchip_sfc_chip_priv *priv = nor->priv;
>> +	struct rockchip_sfc *sfc = priv->sfc;
>> +	u32 dwords;
>> +
>> +	/* Align bytes to dwords */
>> +	dwords = DIV_ROUND_UP(len, sizeof(u32));
>> +	iowrite32_rep(sfc->regbase + SFC_DATA, buf, dwords);
>> +
>> +	return rockchip_sfc_op_reg(nor, opcode, len, SFC_CMD_DIR_WR);
>> +}
>> +
>> +static inline void rockchip_sfc_setup_transfer(struct spi_nor *nor,
>> +					       loff_t from_to,
>> +					       size_t len, u8 op_type)
>> +{
>> +	struct rockchip_sfc_chip_priv *priv = nor->priv;
>> +	struct rockchip_sfc *sfc = priv->sfc;
>> +	u32 reg;
>> +	u8 if_type = 0;
>> +
>> +	if_type = get_if_type(sfc, nor->flash_read);
>> +	writel_relaxed((if_type << SFC_CTRL_DATA_BITS_SHIFT) |
>> +		       (if_type << SFC_CTRL_ADDR_BITS_SHIFT) |
>> +		       (if_type << SFC_CTRL_CMD_BITS_SHIFT) |
>> +		       (sfc->negative_edge ? SFC_CTRL_PHASE_SEL_NEGETIVE : 0),
>> +		       sfc->regbase + SFC_CTRL);
>
> Marek rose an issue when commenting v3:
>
> Looking at that code it seems that even if the hardware can support SPI
> 1-1-n protocols, this driver actually allows SPI n-n-n protocols.
>
> However with the current spi-nor framework, the values of the enum
> read_mode must be understood this way:
> SPI_NOR_FAST or SPI_NOR_NORMAL: SPI 1-1-1 protocol
> SPI_NOR_DUAL: SPI 1-1-2 protocol
> SPI_NOR_QUAD: SPI 1-1-4 protocol
>
> Support to other SPI protocols such as SPI 1-4-4 or SPI 4-4-4 as not been
> accepted in mainline yet.
>
> Below in this driver, spi_nor_scan() is called with the value SPI_NOR_QUAD
> hence it asks the spi-nor framework for using the SPI 1-1-4 (and not SPI
> 4-4-4) *when supported by the QSPI memory*.
>
> Also since the driver was tested with a Winbond w25q256 memory, let me warn
> you that currently the SPI_NOR_QUAD_READ flag is *NOT* set in the "w25q256"
> entry of the spi_nor_ids[] array. So this claims this memory is not capable
> of using the SPI 1-1-4 protocol even if the Winbond memory actually
> supports this protocol. Then the spi-nor framework selects the SPI 1-1-1
> protocol as a fallback.
> That's why you have succeeded in using your driver but it would have failed
> with another QSPI memory with its SPI_NOR_QUAD_READ flag due to a protocol
> mismatch.
>
> So with the current spi-nor framework you must set
> SFC_CTRL_{DATA|ADDR}_BITS_SHIFT to IF_TYPE_STD.
>
> Later, once the patch adding support to other SPI protocols would have been
> accepted in mainline, you could update your driver to tell the spi-nor
> framework that the rockchip controller also supports SPI 1-2-2 and SPI
> 1-4-4 protocols.
>

Thanks, I will fix it in v5.

>
>> +
>> +	if (op_type == SFC_CMD_DIR_WR)
>> +		reg = nor->program_opcode << SFC_CMD_IDX_SHIFT;
>> +	else
>> +		reg = nor->read_opcode << SFC_CMD_IDX_SHIFT;
>> +
>> +	reg |= op_type << SFC_CMD_DIR_SHIFT;
>> +	reg |= (nor->addr_width == 4) ?
>> +		SFC_CMD_ADDR_32BITS : SFC_CMD_ADDR_24BITS;
>> +
>> +	reg |= priv->cs << SFC_CMD_CS_SHIFT;
>> +	reg |= len << SFC_CMD_TRAN_BYTES_SHIFT;
>
> Looking at the definitions of SFC_CMD_TRAN_BYTES_SHIFT (16) and
> SFC_CMD_CS_SHIFT (30), I understand that the bitfield for the transfer
> length lays between bits 16 and 30 hence a 14 bit value at most.
> So what if len is greater than 16384? It overflows in the cs bitfield?
>
> You should apply masks to avoid such overflows and also test the len value
> then report the actual number of transferred bytes.

Sure, will fix.

>
>> +
>> +	if (op_type == SFC_CMD_DIR_RD)
>> +		reg |= SFC_CMD_DUMMY(nor->read_dummy);
>> +
>> +	/* Should minus one as 0x0 means 1 bit flash address */
>> +	writel_relaxed(nor->addr_width * 8 - 1, sfc->regbase + SFC_ABIT);
>> +	writel_relaxed(reg, sfc->regbase + SFC_CMD);
>> +	writel_relaxed(from_to, sfc->regbase + SFC_ADDR);
>> +}
>> +
>> +static int rockchip_sfc_do_dma_transfer(struct spi_nor *nor, loff_t from_to,
>> +					dma_addr_t dma_buf, size_t len,
>> +					u8 op_type)
>> +{
>> +	struct rockchip_sfc_chip_priv *priv = nor->priv;
>> +	struct rockchip_sfc *sfc = priv->sfc;
>> +	u32 reg;
>> +	int err = 0;
>> +
>> +	init_completion(&sfc->cp);
>> +
>> +	writel_relaxed(SFC_ICLR_RX_FULL | SFC_ICLR_RX_UFLOW |
>> +		       SFC_ICLR_TX_OFLOW | SFC_ICLR_TX_EMPTY |
>> +		       SFC_ICLR_TRAN_FINISH | SFC_ICLR_BUS_ERR |
>> +		       SFC_ICLR_NSPI_ERR | SFC_ICLR_DMA,
>> +		       sfc->regbase + SFC_ICLR);
>> +
>> +	/* Enable transfer complete interrupt */
>> +	reg = readl_relaxed(sfc->regbase + SFC_IMR);
>> +	reg &= ~SFC_IMR_TRAN_FINISH;
>> +	writel_relaxed(reg, sfc->regbase + SFC_IMR);
>> +
>> +	rockchip_sfc_setup_transfer(nor, from_to, len, op_type);
>> +	writel_relaxed(dma_buf, sfc->regbase + SFC_DMA_ADDR);
>> +
>> +	/*
>> +	 * Start dma but note that the sfc->dma_buffer is derived from
>> +	 * dmam_alloc_coherent so we don't actually need any sync operations
>> +	 * for coherent dma memory.
>> +	 */
>> +	writel_relaxed(0x1, sfc->regbase + SFC_DMA_TRIGGER);
>> +
>> +	/* Wait for the interrupt. */
>> +	if (!wait_for_completion_timeout(&sfc->cp, msecs_to_jiffies(2000))) {
>> +		dev_err(sfc->dev, "DMA wait for transfer finish timeout\n");
>> +		err = -ETIMEDOUT;
>> +	}
>> +
>> +	/* Disable transfer finish interrupt */
>> +	reg = readl_relaxed(sfc->regbase + SFC_IMR);
>> +	reg |= SFC_IMR_TRAN_FINISH;
>> +	writel_relaxed(reg, sfc->regbase + SFC_IMR);
>> +
>> +	if (err) {
>> +		rockchip_sfc_reset(sfc);
>> +		return err;
>> +	}
>> +
>> +	return rockchip_sfc_wait_op_finish(sfc);
>> +}
>> +
>> +static inline int rockchip_sfc_pio_write(struct rockchip_sfc *sfc, u_char *buf,
>> +					 size_t len)
>> +{
>> +	u32 dwords;
>> +
>> +	/*
>> +	 * Align bytes to dwords, although we will write some extra
>> +	 * bytes to fifo but the transfer bytes number in SFC_CMD
>> +	 * register will make sure we just send out the expected
>> +	 * byte numbers and the extra bytes will be clean before
>> +	 * setting up the next transfer. We should always round up
>> +	 * to align to DWORD as the ahb for Rockchip Socs won't
>> +	 * support non-aligned-to-DWORD transfer.
>> +	 */
>> +	dwords = DIV_ROUND_UP(len, sizeof(u32));
>> +	iowrite32_rep(sfc->regbase + SFC_DATA, buf, dwords);
>> +
>> +	return rockchip_sfc_wait_op_finish(sfc);
>> +}
>> +
>> +static inline int rockchip_sfc_pio_read(struct rockchip_sfc *sfc, u_char *buf,
>> +					size_t len)
>> +{
>> +	rockchip_sfc_read_fifo(sfc, buf, len);
>> +
>> +	return rockchip_sfc_wait_op_finish(sfc);
>> +}
>> +
>> +static int rockchip_sfc_pio_transfer(struct spi_nor *nor, loff_t from_to,
>> +				     size_t len, u_char *buf, u8 op_type)
>> +{
>> +	struct rockchip_sfc_chip_priv *priv = nor->priv;
>> +	struct rockchip_sfc *sfc = priv->sfc;
>> +
>> +	rockchip_sfc_setup_transfer(nor, from_to, len, op_type);
>> +
>> +	if (op_type == SFC_CMD_DIR_WR)
>> +		return rockchip_sfc_pio_write(sfc, buf, len);
>> +	else
>> +		return rockchip_sfc_pio_read(sfc, buf, len);
>> +}
>> +
>> +static int rockchip_sfc_dma_transfer(struct spi_nor *nor, loff_t from_to,
>> +				     size_t len, u_char *buf, u8 op_type)
>> +{
>> +	struct rockchip_sfc_chip_priv *priv = nor->priv;
>> +	struct rockchip_sfc *sfc = priv->sfc;
>> +	size_t offset;
>> +	int ret;
>> +	dma_addr_t dma_addr = 0;
>> +	int dma_dir;
>> +
>> +	dma_dir = (op_type == SFC_CMD_DIR_RD) ?
>> +		   DMA_FROM_DEVICE : DMA_TO_DEVICE;
>> +
>> +	for (offset = 0; offset < len; offset += SFC_DMA_MAX_LEN) {
>> +		size_t trans = min_t(size_t, SFC_DMA_MAX_LEN, len - offset);
>> +
>> +		dma_addr = dma_map_single(NULL, (void *)buf, trans, dma_dir);
> not good: buf may have been allocated with vmalloc() hence the pages of buf
> are not garanteed to be contiguous in physical memory.
>
> Just write a ubifs image into your QSPI memory and try to mount it. You are
> very likely to notice some issues/crashes.
>

You are right. I wasn't aware that the buf from vmalloc will pass in
here so I need to check the address and if that was coming from vmalloc,
we should use pre-allocated dma buf and do a copy here, although it's
quite low performance. :)


>
>> +
>> +		if (dma_mapping_error(sfc->dev, dma_addr)) {
>> +			/*
>> +			 * If we use pre-allocated dma_buffer, we need to
>> +			 * do a copy here.
>> +			 */
>> +			if (op_type == SFC_CMD_DIR_WR)
>> +				memcpy(sfc->buffer, buf + offset, trans);
>> +
>> +			dma_addr = 0;
>> +		}
>> +
>> +		if (op_type == SFC_CMD_DIR_WR)
>> +			/*
>> +			 * Flush the write data from write_buf to dma_addr
>> +			 * if using dynamic allocated dma buffer before dma
>> +			 * moves data from dma_addr to fifo.
>> +			 */
>> +			dma_sync_single_for_device(sfc->dev, dma_addr,
>> +						   trans, DMA_TO_DEVICE);
>> +
>> +
>> +		/* If failing to map dma, use pre-allocated area instead */
>> +		ret = rockchip_sfc_do_dma_transfer(nor, from_to + offset,
>> +						dma_addr ? dma_addr :
>> +						sfc->dma_buffer,
>> +						trans, op_type);
>> +
>> +		if (dma_addr) {
>> +			/*
>> +			 * Invalidate the read data from dma_addr if using
>> +			 * dynamic allocated dma buffer after dma moves data
>> +			 * from fifo to dma_addr.
>> +			 */
>> +			if (op_type == SFC_CMD_DIR_RD)
>> +				dma_sync_single_for_cpu(sfc->dev, dma_addr,
>> +							trans, DMA_FROM_DEVICE);
>> +
>> +			dma_unmap_single(NULL, dma_addr,
>> +					 trans, dma_dir);
>> +		}
>> +
>> +		if (ret) {
>> +			dev_warn(nor->dev, "DMA read timeout\n");
>> +			return ret;
>> +		}
>> +		/*
>> +		 * If we use pre-allocated dma_buffer for read, we need to
>> +		 * do a copy here.
>> +		 */
>> +		if (!dma_addr && (op_type == SFC_CMD_DIR_RD))
>> +			memcpy(buf + offset, sfc->buffer, trans);
>> +	}
>> +
>> +	return len;
>> +}
>> +
>> +static ssize_t rockchip_sfc_do_rd_wr(struct spi_nor *nor, loff_t from_to,
>> +				     size_t len, u_char *buf, u32 op_type)
>> +{
>> +	struct rockchip_sfc_chip_priv *priv = nor->priv;
>> +	struct rockchip_sfc *sfc = priv->sfc;
>> +	int ret;
>> +
>> +	if (likely(sfc->use_dma))
>> +		return rockchip_sfc_dma_transfer(nor, from_to, len,
>> +						 buf, op_type);
>> +
>> +	/* Fall back to PIO mode if DMA isn't present */
>> +	ret = rockchip_sfc_pio_transfer(nor, from_to, len,
>> +					(u_char *)buf, op_type);
>> +	if (ret) {
>> +		if (op_type == SFC_CMD_DIR_RD)
>> +			dev_warn(nor->dev, "PIO read timeout\n");
>> +		else
>> +			dev_warn(nor->dev, "PIO write timeout\n");
>> +		return ret;
>> +	}
>> +
>> +	return len;
>> +}
>> +
>> +static ssize_t rockchip_sfc_read(struct spi_nor *nor, loff_t from,
>> +				 size_t len, u_char *read_buf)
>> +{
>> +	return rockchip_sfc_do_rd_wr(nor, from, len,
>> +				     read_buf, SFC_CMD_DIR_RD);
>> +}
>> +
>> +static ssize_t rockchip_sfc_write(struct spi_nor *nor, loff_t to,
>> +				  size_t len, const u_char *write_buf)
>> +{
>> +	return rockchip_sfc_do_rd_wr(nor, to, len,
>> +				     (u_char *)write_buf,
>> +				     SFC_CMD_DIR_WR);
>> +}
>> +
>> +static int rockchip_sfc_register(struct device_node *np,
>> +				 struct rockchip_sfc *sfc)
>> +{
>> +	struct device *dev = sfc->dev;
>> +	struct mtd_info *mtd;
>> +	struct spi_nor *nor;
>> +	int ret;
>> +
>> +	nor = &sfc->flash[sfc->num_chip].nor;
>> +	nor->dev = dev;
>> +	spi_nor_set_flash_node(nor, np);
>> +
>> +	ret = of_property_read_u8(np, "reg", &sfc->flash[sfc->num_chip].cs);
>> +	if (ret) {
>> +		dev_err(dev, "No reg property for %s\n",
>> +			np->full_name);
>> +		return ret;
>> +	}
>> +
>> +	ret = of_property_read_u32(np, "spi-max-frequency",
>> +			&sfc->flash[sfc->num_chip].clk_rate);
>> +	if (ret) {
>> +		dev_err(dev, "No spi-max-frequency property for %s\n",
>> +			np->full_name);
>> +		return ret;
>> +	}
>> +
>> +	sfc->flash[sfc->num_chip].sfc = sfc;
>> +	nor->priv = &(sfc->flash[sfc->num_chip]);
>> +
>> +	nor->prepare = rockchip_sfc_prep;
>> +	nor->unprepare = rockchip_sfc_unprep;
>> +	nor->read_reg = rockchip_sfc_read_reg;
>> +	nor->write_reg = rockchip_sfc_write_reg;
>> +	nor->read = rockchip_sfc_read;
>> +	nor->write = rockchip_sfc_write;
>> +	nor->erase = NULL;
>> +	ret = spi_nor_scan(nor, NULL, SPI_NOR_QUAD);
>> +	if (ret)
>> +		return ret;
>> +
>> +	mtd = &(nor->mtd);
>> +	mtd->name = np->name;
>> +	ret = mtd_device_register(mtd, NULL, 0);
>> +	if (ret)
>> +		return ret;
>> +
>> +	sfc->num_chip++;
>> +	return 0;
>> +}
>> +
>> +static void rockchip_sfc_unregister_all(struct rockchip_sfc *sfc)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < sfc->num_chip; i++)
>> +		mtd_device_unregister(&sfc->flash[i].nor.mtd);
>> +}
>> +
>> +static int rockchip_sfc_register_all(struct rockchip_sfc *sfc)
>> +{
>> +	struct device *dev = sfc->dev;
>> +	struct device_node *np;
>> +	int ret;
>> +
>> +	for_each_available_child_of_node(dev->of_node, np) {
>> +		ret = rockchip_sfc_register(np, sfc);
>> +		if (ret)
>> +			goto fail;
>> +
>> +		if (sfc->num_chip == SFC_MAX_CHIPSELECT_NUM) {
>> +			dev_warn(dev, "Exceeds the max cs limitation\n");
>> +			break;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +
>> +fail:
>> +	dev_err(dev, "Failed to register all chips\n");
>> +	/* Unregister all the _registered_ nor flash */
>> +	rockchip_sfc_unregister_all(sfc);
>> +	return ret;
>> +}
>> +
>> +static irqreturn_t rockchip_sfc_irq_handler(int irq, void *dev_id)
>> +{
>> +	struct rockchip_sfc *sfc = dev_id;
>> +	u32 reg;
>> +
>> +	reg = readl_relaxed(sfc->regbase + SFC_RISR);
>> +	dev_dbg(sfc->dev, "Get irq: 0x%x\n", reg);
>> +
>> +	/* Clear interrupt */
>> +	writel_relaxed(reg, sfc->regbase + SFC_ICLR);
>> +
>> +	if (reg & SFC_RISR_TRAN_FINISH)
>> +		complete(&sfc->cp);
>> +
>> +	return IRQ_HANDLED;
>> +}
>> +
>> +static int rockchip_sfc_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct resource *res;
>> +	struct rockchip_sfc *sfc;
>> +	int ret;
>> +
>> +	sfc = devm_kzalloc(dev, sizeof(*sfc), GFP_KERNEL);
>> +	if (!sfc)
>> +		return -ENOMEM;
>> +
>> +	platform_set_drvdata(pdev, sfc);
>> +	sfc->dev = dev;
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	sfc->regbase = devm_ioremap_resource(dev, res);
>> +	if (IS_ERR(sfc->regbase))
>> +		return PTR_ERR(sfc->regbase);
>> +
>> +	sfc->clk = devm_clk_get(&pdev->dev, "sfc");
>> +	if (IS_ERR(sfc->clk)) {
>> +		dev_err(&pdev->dev, "Failed to get sfc interface clk\n");
>> +		return PTR_ERR(sfc->clk);
>> +	}
>> +
>> +	sfc->hclk = devm_clk_get(&pdev->dev, "hsfc");
>> +	if (IS_ERR(sfc->hclk)) {
>> +		dev_err(&pdev->dev, "Failed to get sfc ahp clk\n");
>> +		return PTR_ERR(sfc->hclk);
>> +	}
>> +
>> +	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
>> +	if (ret) {
>> +		dev_warn(dev, "Unable to set dma mask\n");
>> +		return ret;
>> +	}
>> +
>> +	sfc->buffer = dmam_alloc_coherent(dev, SFC_DMA_MAX_LEN,
>> +			&sfc->dma_buffer, GFP_KERNEL);
>> +	if (!sfc->buffer)
>> +		return -ENOMEM;
>> +
>> +	mutex_init(&sfc->lock);
>> +
>> +	ret = clk_prepare_enable(sfc->hclk);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "Failed to enable hclk\n");
>> +		goto err_hclk;
>> +	}
>> +
>> +	ret = clk_prepare_enable(sfc->clk);
>> +	if (ret) {
>> +		dev_err(&pdev->dev, "Failed to enable clk\n");
>> +		goto err_clk;
>> +	}
>> +
>> +	sfc->use_dma = !of_property_read_bool(sfc->dev->of_node,
>> +					      "rockchip,sfc-no-DMA");
>> +
>> +	sfc->negative_edge = of_device_is_compatible(sfc->dev->of_node,
>> +						     "rockchip,rk1108-sfc");
>> +	/* Find the irq */
>> +	ret = platform_get_irq(pdev, 0);
>> +	if (ret < 0) {
>> +		dev_err(dev, "Failed to get the irq\n");
>> +		goto err_irq;
>> +	}
>> +
>> +	ret = devm_request_irq(dev, ret, rockchip_sfc_irq_handler,
>> +			       0, pdev->name, sfc);
>> +	if (ret) {
>> +		dev_err(dev, "Failed to request irq\n");
>> +		goto err_irq;
>> +	}
>> +
>> +	sfc->num_chip = 0;
>> +	ret = rockchip_sfc_init(sfc);
>> +	if (ret)
>> +		goto err_irq;
>> +
>> +	pm_runtime_get_noresume(&pdev->dev);
>> +	pm_runtime_set_active(&pdev->dev);
>> +	pm_runtime_enable(&pdev->dev);
>> +	pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
>> +	pm_runtime_use_autosuspend(&pdev->dev);
>> +
>> +	ret = rockchip_sfc_register_all(sfc);
>> +	if (ret)
>> +		goto err_register;
>> +
>> +	clk_disable_unprepare(sfc->clk);
>> +	pm_runtime_put_autosuspend(&pdev->dev);
>> +	return 0;
>> +
>> +err_register:
>> +	pm_runtime_disable(&pdev->dev);
>> +	pm_runtime_set_suspended(&pdev->dev);
>> +	pm_runtime_put_noidle(&pdev->dev);
>> +err_irq:
>> +	clk_disable_unprepare(sfc->clk);
>> +err_clk:
>> +	clk_disable_unprepare(sfc->hclk);
>> +err_hclk:
>> +	mutex_destroy(&sfc->lock);
>> +	return ret;
>> +}
>> +
>> +static int rockchip_sfc_remove(struct platform_device *pdev)
>> +{
>> +	struct rockchip_sfc *sfc = platform_get_drvdata(pdev);
>> +
>> +	pm_runtime_get_sync(&pdev->dev);
>> +	pm_runtime_disable(&pdev->dev);
>> +	pm_runtime_put_noidle(&pdev->dev);
>> +
>> +	rockchip_sfc_unregister_all(sfc);
>> +	mutex_destroy(&sfc->lock);
>> +	clk_disable_unprepare(sfc->clk);
>> +	clk_disable_unprepare(sfc->hclk);
>> +	return 0;
>> +}
>> +
>> +#ifdef CONFIG_PM
>> +int rockchip_sfc_runtime_suspend(struct device *dev)
>> +{
>> +	struct rockchip_sfc *sfc = dev_get_drvdata(dev);
>> +
>> +	clk_disable_unprepare(sfc->hclk);
>> +	return 0;
>> +}
>> +
>> +int rockchip_sfc_runtime_resume(struct device *dev)
>> +{
>> +	struct rockchip_sfc *sfc = dev_get_drvdata(dev);
>> +
>> +	clk_prepare_enable(sfc->hclk);
>> +	return rockchip_sfc_reset(sfc);
>> +}
>> +#endif /* CONFIG_PM */
>> +
>> +static const struct of_device_id rockchip_sfc_dt_ids[] = {
>> +	{ .compatible = "rockchip,sfc"},
>> +	{ /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(of, rockchip_sfc_dt_ids);
>> +
>> +static const struct dev_pm_ops rockchip_sfc_dev_pm_ops = {
>> +	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
>> +				pm_runtime_force_resume)
>> +	SET_RUNTIME_PM_OPS(rockchip_sfc_runtime_suspend,
>> +			   rockchip_sfc_runtime_resume, NULL)
>> +};
>> +
>> +static struct platform_driver rockchip_sfc_driver = {
>> +	.driver = {
>> +		.name	= "rockchip-sfc",
>> +		.of_match_table = rockchip_sfc_dt_ids,
>> +		.pm = &rockchip_sfc_dev_pm_ops,
>> +	},
>> +	.probe	= rockchip_sfc_probe,
>> +	.remove	= rockchip_sfc_remove,
>> +};
>> +module_platform_driver(rockchip_sfc_driver);
>> +
>> +MODULE_LICENSE("GPL v2");
>> +MODULE_DESCRIPTION("Rockchip Serial Flash Controller Driver");
>> +MODULE_AUTHOR("Shawn Lin <shawn.lin at rock-chips.com>");
>>
>
>
>
>


-- 
Best Regards
Shawn Lin




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