[PATCH 2/2] mtd: spi-nor: add rockchip serial flash controller driver
Shawn Lin
shawn.lin at rock-chips.com
Tue Nov 15 17:59:18 PST 2016
Hi Marek,
Thanks for reviewing my patch, and it's really
helpful to improve it. :) See my feedback for
your comments below.
On 2016/11/16 4:52, Marek Vasut wrote:
> On 11/11/2016 10:16 AM, Shawn Lin wrote:
>> Add rockchip serial flash controller driver
>>
>> Signed-off-by: Shawn Lin <shawn.lin at rock-chips.com>
>
>
> [...]
>
>> diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
>> index 4a682ee..48c5e0e 100644
>> --- a/drivers/mtd/spi-nor/Kconfig
>> +++ b/drivers/mtd/spi-nor/Kconfig
>> @@ -65,6 +65,13 @@ config SPI_HISI_SFC
>> help
>> This enables support for hisilicon SPI-NOR flash controller.
>>
>> +config SPI_ROCKCHIP_SFC
>
> Keep this list sorted please.
yup, will fix.
>
>> + 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.
>> +
>> config SPI_NXP_SPIFI
>> tristate "NXP SPI Flash Interface (SPIFI)"
>> depends on OF && (ARCH_LPC18XX || COMPILE_TEST)
>
>
> [...]
>
>> +/* Interrypt mask */
>
> Interrupt :)
will fix. :)
>
>> +#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)
>
>
> [...]
>
>> +enum rockchip_sfc_iftype {
>> + IF_TYPE_STD,
>> + IF_TYPE_DUAL,
>> + IF_TYPE_QUAD,
>> +};
>> +
>> +struct rockchip_sfc {
>> + struct device *dev;
>> + struct mutex lock;
>> + void __iomem *regbase;
>> + struct clk *hclk;
>> + struct clk *clk;
>> + void *buffer;
>> + dma_addr_t dma_buffer;
>
> The naming (buffer) could use some improvement or comment for clarification.
>
>> + struct completion cp;
>> + struct spi_nor *nor[SFC_MAX_CHIP_NUM];
>
> Should be MAX_CHIPSELECT_NUM , for clarity.
seems sane, will fix.
>
>> + u32 num_chip;
>
> u8
>
>> + bool use_dma;
>> + bool negative_edge;
>
> Negative edge ... of what ?
For how the inner sample logic to letch the data. It should be
configured differently for different Socs. I will add a comment
here to clarify it.
>
>> +};
>> +
>> +struct rockchip_sfc_priv {
>> + u32 cs;
>
> Doesn't this board support only 4 CS ? Use u8 :-)
>
good catch, will fix it.
>> + u32 clk_rate;
>> + struct rockchip_sfc *sfc;
>> +};
>> +
>> +static int get_if_type(enum read_mode flash_read)
>> +{
>> + enum rockchip_sfc_iftype if_type;
>> +
>> + switch (flash_read) {
>> + case SPI_NOR_DUAL:
>> + if_type = IF_TYPE_DUAL;
>> + break;
>> + case SPI_NOR_QUAD:
>> + if_type = IF_TYPE_QUAD;
>> + break;
>> + case SPI_NOR_NORMAL:
>> + case SPI_NOR_FAST:
>> + default:
>
> Should the default case really fall back to 1-bit mode or should it
> rather report error ?
It's derived from nor->flash_read, so personlly I think there should
never fall into the default case, but it would make sense to return
-EINVAL instead of falling into 1-bit mode. I will fix it.
>
>> + if_type = IF_TYPE_STD;
>> + break;
>> + }
>> +
>> + return if_type;
>> +}
>> +
>> +static int rockchip_sfc_reset(struct rockchip_sfc *sfc)
>> +{
>> + unsigned long timeout = jiffies + HZ;
>> + int err = -ETIMEDOUT;
>> + u32 status;
>> +
>> + writel_relaxed(SFC_RCVR_RESET, sfc->regbase + SFC_RCVR);
>> +
>> + while (time_before(jiffies, timeout)) {
>
> Would readl_poll_*() from include/linux/iopoll.h help here ?
>
Brilliant, it looks great to me.
>> + status = readl_relaxed(sfc->regbase + SFC_RCVR);
>> + if (!(status & SFC_RCVR_RESET)) {
>> + err = 0;
>> + break;
>> + }
>> + msleep(20);
>> + }
>> +
>> + if (err)
>> + dev_err(sfc->dev, "SFC reset never finished\n");
>
> Should the writel() below be executed if an error happened ?
It's needed since when doing reset after failing to finish
a previous transfer for whatever reason, we could observed some of the
interrupts triggered. Although we masked them but we could still
find them from the raw interrupt status register. So cleaning
it explicitly make senses.
>
>> + 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 */
>
> What phase ? Please clarify the comment. Also, don't you have to
> configure the register if sfc->negative_edge == 0 too ?
will elaborate more.
Your comment makes me think it twice. The loader should
already set this but we could override it agian in case
of some other code clear it. I was assuming that the reset
value of it meets what we need for "sfc->negative_edge == 0",
but I think I am wrong since we still need to prevent some other
whatever code modified it before jumping into rockchip_sfc_probe.
So yes, I will fix it. :)
>
>> + if (sfc->negative_edge)
>> + writel_relaxed(SFC_CTRL_PHASE_SEL_NEGETIVE <<
>> + SFC_CTRL_PHASE_SEL_SHIFT,
>> + sfc->regbase + SFC_CTRL);
>> + return 0;
>> +}
>> +
>> +static int rockchip_sfc_prep(struct spi_nor *nor, enum spi_nor_ops ops)
>> +{
>> + struct rockchip_sfc_priv *priv = nor->priv;
>> + struct rockchip_sfc *sfc = priv->sfc;
>> + int ret;
>> +
>> + mutex_lock(&sfc->lock);
>> +
>> + 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_priv *priv = nor->priv;
>> + struct rockchip_sfc *sfc = priv->sfc;
>> +
>> + clk_disable_unprepare(sfc->clk);
>> + mutex_unlock(&sfc->lock);
>> +}
>> +
>> +static int rockchip_sfc_wait_op_finish(struct rockchip_sfc *sfc)
>> +{
>> + unsigned long timeout = jiffies + 2 * HZ;
>> + int err = -ETIMEDOUT;
>> + 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.
>> + */
>> + while (time_before(jiffies, timeout)) {
>
> readl_poll_*() ?
sure.
>
>> + status = readl_relaxed(sfc->regbase + SFC_FSR);
>> + if (((status >> SFC_FSR_TX_EMPTY_SHIFT) &
>> + SFC_FSR_TX_EMPTY_MASK) == SFC_FSR_TX_IS_EMPTY) {
>> + err = 0;
>> + break;
>> + }
>> + msleep(20);
>> + }
>> +
>> + if (err)
>> + dev_err(sfc->dev, "SFC tx never empty\n");
>> +
>> + return err;
>> +}
>> +
>> +static int rockchip_sfc_op_reg(struct spi_nor *nor,
>> + u8 opcode, int len, u8 optype)
>> +{
>> + struct rockchip_sfc_priv *priv = nor->priv;
>> + struct rockchip_sfc *sfc = priv->sfc;
>> + u32 reg;
>> +
>> + if (((readl_relaxed(sfc->regbase + SFC_FSR) >> SFC_FSR_TX_EMPTY_SHIFT) &
>> + SFC_FSR_TX_EMPTY_MASK) != SFC_FSR_TX_IS_EMPTY ||
>> + ((readl_relaxed(sfc->regbase + SFC_FSR) >>
>> + SFC_FSR_RX_EMPTY_SHIFT) &
>> + SFC_FSR_RX_EMPTY_MASK) != SFC_FSR_RX_IS_EMPTY ||
>> + (readl_relaxed(sfc->regbase + SFC_SR) == SFC_SR_IS_BUSY))
>> + rockchip_sfc_reset(sfc);
>
> This is chaos, please fix this condition so it's actually readable. You
> can ie. read the FSR into a variable, do your shifting/anding magic and
> then do if (var1 || var2 || var3) {} .
okay, will make it more clearly.
>
>> + reg = (opcode & SFC_CMD_IDX_MASK) << SFC_CMD_IDX_SHIFT;
>> + reg |= (len & SFC_CMD_TRAN_BYTES_MASK) << SFC_CMD_TRAN_BYTES_SHIFT;
>> + reg |= (priv->cs & SFC_CMD_CS_MASK) << SFC_CMD_CS_SHIFT;
>> + reg |= (optype & SFC_CMD_DIR_MASK) << SFC_CMD_DIR_SHIFT;
>> +
>> + writel_relaxed(reg, sfc->regbase + SFC_CMD);
>> +
>> + return rockchip_sfc_wait_op_finish(sfc);
>> +}
>> +
>> +static int rockchip_sfc_read_reg(struct spi_nor *nor, u8 opcode,
>> + u8 *buf, int len)
>> +{
>> + struct rockchip_sfc_priv *priv = nor->priv;
>> + struct rockchip_sfc *sfc = priv->sfc;
>> + int ret;
>> + u32 tmp;
>> + u32 i;
>> +
>> + ret = rockchip_sfc_op_reg(nor, opcode, len, SFC_CMD_DIR_RD);
>> + if (ret)
>> + return ret;
>> +
>> + while (len > 0) {
>> + tmp = readl_relaxed(sfc->regbase + SFC_DATA);
>> + for (i = 0; i < len; i++)
>> + *buf++ = (u8)((tmp >> (i * 8)) & 0xff);
>
> Won't this fail for len > 4 ?
nope, this loop will reduce 4 for each successful readl. And
reading the remained bytes which isn't aligned to DWORD, isn't it?
>
> Also, you can use ioread32_rep() here, but (!) that won't work for
> unaligned reads, which I dunno if they can happen here, but please do
> double-check.
yes, I have checked this API as well as others like memcpy_{to,from}io
, etc. They will generate a external abort for arm core as the unaligned
(DWORD) read/write via AHB aren't supported by Rockchip Socs. So I have
to open code these stuff. This could be easily found for other
upstreamed rockchip drivers. :)
>
>> + len = len - 4;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int rockchip_sfc_write_reg(struct spi_nor *nor, u8 opcode,
>> + u8 *buf, int len)
>> +{
>> + struct rockchip_sfc_priv *priv = nor->priv;
>> + struct rockchip_sfc *sfc = priv->sfc;
>> + u32 words, i;
>> +
>> + /* Align bytes to words */
>> + words = (len + 3) >> 2;
>> +
>> + for (i = 0; i < words; i++)
>> + writel_relaxed(*(buf + 4 * i), sfc->regbase + SFC_DATA);
>
> See above about the ioread32_rep()/iowrite32_rep(), but careful about
> unaligned (len % 4 != 0) case.
Ditto for above. :)
>
>> + return rockchip_sfc_op_reg(nor, opcode, len, SFC_CMD_DIR_WR);
>> +}
>> +
>> +static int rockchip_sfc_dma_transfer(struct spi_nor *nor, loff_t from_to,
>> + dma_addr_t dma_buf, size_t len, u8 op_type)
>> +{
>> + struct rockchip_sfc_priv *priv = nor->priv;
>> + struct rockchip_sfc *sfc = priv->sfc;
>> + u32 reg;
>> + u8 if_type = 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);
>> +
>> + if (op_type == SFC_CMD_DIR_WR)
>> + reg = (SFC_CMD_DIR_WR << SFC_CMD_DIR_SHIFT) |
>> + ((nor->program_opcode & SFC_CMD_IDX_MASK) <<
>> + SFC_CMD_IDX_SHIFT);
>> + else
>> + reg = (SFC_CMD_DIR_RD << SFC_CMD_DIR_SHIFT) |
>> + ((nor->read_opcode & SFC_CMD_IDX_MASK) <<
>> + SFC_CMD_IDX_SHIFT);
>
> reg = nor->read_opcode & SFC_CMD_IDX_MASK) << SFC_CMD_IDX_SHIFT;
> reg |= op_type << SFC_CMD_DIR_SHIFT;
will improve.
>
>> + reg |= ((nor->addr_width == 4) ? SFC_CMD_ADDR_32BITS
>> + : SFC_CMD_ADDR_24BITS) << SFC_CMD_ADDR_SHIFT;
>
> Why don't you just define those SFC_CMD_ADDR_24BITS and co. with the
> shift in those bitfields already ? Then you wouldn't have to riddle this
> driver with FOO << BAR, but you'd only have FOO all over the place.
>
sounds good, will improve them..
>> + if_type = get_if_type(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 |
>
> Parenthesis missing around the statements ,
> (if_type << FOO) | (... << bar)
>
will improve it.
>> + sfc->negative_edge ?
>> + SFC_CTRL_PHASE_SEL_NEGETIVE << SFC_CTRL_PHASE_SEL_SHIFT :
>> + SFC_CTRL_PHASE_SEL_POSITIVE << SFC_CTRL_PHASE_SEL_SHIFT,
>> + sfc->regbase + SFC_CTRL);
>> +
>> + reg |= (priv->cs & SFC_CMD_CS_MASK) << SFC_CMD_CS_SHIFT;
>> + reg |= (len & SFC_CMD_TRAN_BYTES_MASK) << SFC_CMD_TRAN_BYTES_SHIFT;
>> +
>> + if (op_type == SFC_CMD_DIR_RD)
>> + reg |= (nor->read_dummy & SFC_CMD_DUMMY_MASK) <<
>> + SFC_CMD_DUMMY_SHIFT;
>
> Just define SFC_CMD_DUMMY(x) \
> (((x) & SFC_CMD_DUMMY_MASK) << SFC_CMD_DUMMY_SHIFT)
>
> And then use it ... reg |= SFC_CMD_DUMMY(nor->read_dummy);
sure.
>
>> + /* 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);
>> + writel_relaxed(dma_buf, sfc->regbase + SFC_DMA_ADDR);
>
> I hope the DMA buffer management is implemented correctly and you're not
> running into any weird cache issues.
you are right. I should sync it after doing read and before doing write.
>
>> + /* Start dma */
>> + 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.");
>> + return -ETIMEDOUT;
>> + }
>> +
>> + /* Disable transfer finish interrupt */
>> + reg = readl_relaxed(sfc->regbase + SFC_IMR);
>> + reg |= SFC_IMR_TRAN_FINISH;
>> + writel_relaxed(reg, sfc->regbase + SFC_IMR);
>> +
>> + 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 words, tx_wl, count, i;
>> + unsigned long timeout;
>> + int ret = 0;
>> + u32 *tbuf = (u32 *)buf;
>> +
>> + /* Align bytes to words */
>> + words = (len + 3) >> 2;
>> +
>> + while (words) {
>
> See iowrite32_rep() above, but I suspect you'll run into problems with
> $len which is not multiple of 4 .
>
Ditto for above.
>> + tx_wl = (readl_relaxed(sfc->regbase + SFC_FSR) >>
>> + SFC_FSR_TX_WATER_LVL_SHIFT) &
>> + SFC_FSR_TX_WATER_LVL_MASK;
>> +
>> + if (tx_wl > 0) {
>> + count = min_t(u32, words, tx_wl);
>> + for (i = 0; i < count; i++) {
>> + writel_relaxed(*tbuf++,
>> + sfc->regbase + SFC_DATA);
>> + words--;
>> + }
>> +
>> + if (words == 0)
>> + break;
>> + timeout = 0;
>> + } else {
>> + mdelay(1);
>> + if (timeout++ > SFC_MAX_IDLE_RETRY) {
>> + ret = -ETIMEDOUT;
>> + break;
>> + }
>> + }
>> + }
>> +
>> + if (ret)
>> + return ret;
>> + else
>> + return rockchip_sfc_wait_op_finish(sfc);
>> +}
>> +
>> +static inline int rockchip_sfc_pio_read(struct rockchip_sfc *sfc, u_char *buf,
>> + size_t len)
>> +{
>> + u32 words, rx_wl, count, i;
>> + unsigned long timeout;
>> + int ret = 0;
>> + u32 tmp;
>> + u32 *tbuf = (u32 *)buf;
>> + u_char *tbuf2;
>> +
>> + words = len >> 2;
>> + /* Get the remained bytes */
>> + len = len & 0x3;
>
> See above.
>
>> + while (words) {
>> + rx_wl = (readl_relaxed(sfc->regbase + SFC_FSR) >>
>> + SFC_FSR_RX_WATER_LVL_SHIFT) &
>> + SFC_FSR_RX_WATER_LVL_MASK;
>> +
>> + if (rx_wl > 0) {
>> + count = min_t(u32, words, rx_wl);
>> + for (i = 0; i < count; i++) {
>> + *tbuf++ = readl_relaxed(sfc->regbase +
>> + SFC_DATA);
>> + words--;
>> + }
>> +
>> + if (words == 0)
>> + break;
>> + timeout = 0;
>> + } else {
>> + mdelay(1);
>> + if (timeout++ > SFC_MAX_IDLE_RETRY) {
>> + ret = -ETIMEDOUT;
>> + break;
>> + }
>> + }
>> + }
>> +
>> + if (ret)
>> + return ret;
>> +
>> + /* Read the remained bytes */
>> + timeout = 0;
>> + tbuf2 = (u_char *)tbuf;
>> + while (len) {
>> + rx_wl = (readl_relaxed(sfc->regbase + SFC_FSR) >>
>> + SFC_FSR_RX_WATER_LVL_SHIFT) &
>> + SFC_FSR_RX_WATER_LVL_MASK;
>> + if (rx_wl > 0) {
>> + tmp = readl_relaxed(sfc->regbase + SFC_DATA);
>> + for (i = 0; i < len; i++)
>> + tbuf2[i] = (u8)((tmp >> (i * 8)) & 0xff);
>> + goto done;
>> + } else {
>> + mdelay(1);
>> + if (timeout++ > SFC_MAX_IDLE_RETRY) {
>> + ret = -ETIMEDOUT;
>> + break;
>> + }
>> + }
>> + }
>> +done:
>> + if (ret)
>> + return ret;
>> + else
>> + 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_priv *priv = nor->priv;
>> + struct rockchip_sfc *sfc = priv->sfc;
>> + u32 reg;
>> + u8 if_type = 0;
>> +
>> + if (op_type == SFC_CMD_DIR_WR)
>> + reg = (SFC_CMD_DIR_WR << SFC_CMD_DIR_SHIFT) |
>> + ((nor->program_opcode & SFC_CMD_IDX_MASK) <<
>> + SFC_CMD_IDX_SHIFT);
>> + else
>> + reg = (SFC_CMD_DIR_RD << SFC_CMD_DIR_SHIFT) |
>> + ((nor->read_opcode & SFC_CMD_IDX_MASK) <<
>> + SFC_CMD_IDX_SHIFT);
>
> See above regarding this condition. I think you can factor out this
> common code too. Also nuke the bitshifts , see my comments on
> rockchip_sfc_dma_transfer .
>
sure. Will fix the bitshifts and factor out the common code.
>> + reg |= ((nor->addr_width == 4) ? SFC_CMD_ADDR_32BITS
>> + : SFC_CMD_ADDR_24BITS) << SFC_CMD_ADDR_SHIFT;
>> +
>> + if_type = get_if_type(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 << SFC_CTRL_PHASE_SEL_SHIFT :
>> + SFC_CTRL_PHASE_SEL_POSITIVE << SFC_CTRL_PHASE_SEL_SHIFT,
>> + sfc->regbase + SFC_CTRL);
>> +
>> + reg |= (priv->cs & SFC_CMD_CS_MASK) << SFC_CMD_CS_SHIFT;
>> + reg |= (len & SFC_CMD_TRAN_BYTES_MASK) << SFC_CMD_TRAN_BYTES_SHIFT;
>> +
>> + if (op_type == SFC_CMD_DIR_RD)
>> + reg |= (nor->read_dummy & SFC_CMD_DUMMY_MASK) <<
>> + SFC_CMD_DUMMY_SHIFT;
>> +
>> + /* 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);
>> +
>> + 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 ssize_t rockchip_sfc_read(struct spi_nor *nor, loff_t from, size_t len,
>> + u_char *read_buf)
>> +{
>> + struct rockchip_sfc_priv *priv = nor->priv;
>> + struct rockchip_sfc *sfc = priv->sfc;
>> + size_t offset;
>> + int ret;
>> + dma_addr_t dma_addr = 0;
>> +
>> + if (!sfc->use_dma)
>> + goto no_dma;
>> +
>> + 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 *)read_buf,
>> + trans, DMA_FROM_DEVICE);
>> + if (dma_mapping_error(sfc->dev, dma_addr))
>> + dma_addr = 0;
>> +
>> + /* Fail to map dma, use pre-allocated area instead */
>> + ret = rockchip_sfc_dma_transfer(nor, from + offset,
>> + dma_addr ? dma_addr :
>> + sfc->dma_buffer,
>> + trans, SFC_CMD_DIR_RD);
>> + if (ret) {
>> + dev_warn(nor->dev, "DMA read timeout\n");
>> + return ret;
>> + }
>> + if (!dma_addr)
>> + memcpy(read_buf + offset, sfc->buffer, trans);
>> + }
>> +
>> + return len;
>> +
>> +no_dma:
>> + ret = rockchip_sfc_pio_transfer(nor, from, len,
>> + read_buf, SFC_CMD_DIR_RD);
>> + if (ret) {
>> + dev_warn(nor->dev, "PIO read timeout\n");
>> + return ret;
>> + }
>> + return len;
>> +}
>> +
>> +static ssize_t rockchip_sfc_write(struct spi_nor *nor, loff_t to,
>> + size_t len, const u_char *write_buf)
>> +{
>> + struct rockchip_sfc_priv *priv = nor->priv;
>> + struct rockchip_sfc *sfc = priv->sfc;
>> + size_t offset;
>> + int ret;
>> + dma_addr_t dma_addr = 0;
>> +
>> + if (!sfc->use_dma)
>> + goto no_dma;
>
> Seems like there's a lot of similarity between read/write .
I was thinking to combine read/write with a extra argument to
indicate WR/RD. But as we could see still some differece between
WR and RD and there are already some condiction checks. So it
will make the code hard to read with stuffing lots of condition
checks. So I splited out read and write strightforward. :)
>
>> + 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 *)write_buf,
>> + trans, DMA_TO_DEVICE);
>> + if (dma_mapping_error(sfc->dev, dma_addr)) {
>> + dma_addr = 0;
>> + memcpy(sfc->buffer, write_buf + offset, trans);
>> + }
>> +
>> + /* Fail to map dma, use pre-allocated area instead */
>> + ret = rockchip_sfc_dma_transfer(nor, to + offset,
>> + dma_addr ? dma_addr :
>> + sfc->dma_buffer,
>> + trans, SFC_CMD_DIR_WR);
>> + if (dma_addr)
>> + dma_unmap_single(NULL, dma_addr,
>> + trans, DMA_TO_DEVICE);
>> + if (ret) {
>> + dev_warn(nor->dev, "DMA write timeout\n");
>> + return ret;
>> + }
>> + }
>> +
>> + return len;
>> +no_dma:
>> + ret = rockchip_sfc_pio_transfer(nor, to, len,
>> + (u_char *)write_buf, SFC_CMD_DIR_WR);
>> + if (ret) {
>> + dev_warn(nor->dev, "PIO write timeout\n");
>> + return ret;
>> + }
>> + return len;
>> +}
>> +
>> +/**
>> + * Get spi flash device information and register it as a mtd device.
>> + */
>> +static int rockchip_sfc_register(struct device_node *np,
>> + struct rockchip_sfc *sfc)
>> +{
>> + struct device *dev = sfc->dev;
>> + struct spi_nor *nor;
>> + struct rockchip_sfc_priv *priv;
>> + struct mtd_info *mtd;
>> + int ret;
>> +
>> + nor = devm_kzalloc(dev, sizeof(*nor), GFP_KERNEL);
>> + if (!nor)
>> + return -ENOMEM;
>
> You can embed struct spi_nor in struct rockchip_sfc_priv and drop this
> allocation . Also it'd be a good idea to rename rockchip_sfc_priv to
> something like rockchip_sfc_chip_priv to make it explicit this is a
> per-chip private data -- which you can even pre-allocate in rockchi_sfc
> structure as a static array of (four) such structures (see cadence qspi
> driver for how this is done there).
>
sure, will improve it.
>> + nor->dev = dev;
>> + spi_nor_set_flash_node(nor, np);
>> +
>> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
>> + if (!priv)
>> + return -ENOMEM;
>> +
>> + ret = of_property_read_u32(np, "reg", &priv->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",
>> + &priv->clk_rate);
>> + if (ret) {
>> + dev_err(dev, "No spi-max-frequency property for %s\n",
>> + np->full_name);
>> + return ret;
>> + }
>> +
>> + priv->sfc = sfc;
>> + nor->priv = priv;
>> +
>> + 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->nor[sfc->num_chip] = nor;
>> + 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->nor[i]->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_CHIP_NUM) {
>> + dev_warn(dev, "Exceeds the max cs limitation\n");
>> + break;
>> + }
>> + }
>> +
>> + return 0;
>> +
>> +fail:
>> + dev_err(dev, "Failed to register all chip\n");
>> + rockchip_sfc_unregister_all(sfc);
>
> See cadence qspi where we only unregister the registered flashes.
> Implement it the same way here.
>
yup, but I'm afraid that rockchip_sfc_unregister_all confused you
as it actually unregisters the registered ones, not for all.
static void rockchip_sfc_unregister_all(struct rockchip_sfc *sfc)
{
int i;
for (i = 0; i < sfc->num_chip; i++)
mtd_device_unregister(&sfc->nor[i]->mtd);
}
sfc->num_chip stands for how many flashes registered successfully.
>> + 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_IRQ_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;
>> + }
>> +
>> + if (of_property_read_bool(sfc->dev->of_node, "rockchip,sfc-no-dma"))
>> + sfc->use_dma = false;
>> + else
>> + sfc->use_dma = true;
>
> sfc->use_dma = !of_property_read_bool(sfc->dev->of_node,
> "rockchip,sfc-no-dma");
>
will improve.
>> + if (of_device_is_compatible(sfc->dev->of_node,
>> + "rockchip,rk1108-sfc"))
>> + sfc->negative_edge = true;
>> + else
>> + sfc->negative_edge = false;
>
> See above
>
Ditto.
>> + /* 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;
>> + }
>> +
>> + ret = rockchip_sfc_init(sfc);
>> + if (ret)
>> + goto err_init;
>> +
>> + ret = rockchip_sfc_register_all(sfc);
>> + if (ret)
>> + goto err_init;
>> +
>> + clk_disable_unprepare(sfc->clk);
>> + return 0;
>> +
>> +err_irq:
>> +err_init:
>
> Drop the err_irq: label unless you plan to handle the error (which you
> should).
will remove.
>
>> + 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);
>> +
>> + rockchip_sfc_unregister_all(sfc);
>> + mutex_destroy(&sfc->lock);
>> + clk_disable_unprepare(sfc->clk);
>> + clk_disable_unprepare(sfc->hclk);
>> + return 0;
>> +}
>> +
>> +static const struct of_device_id rockchip_sfc_dt_ids[] = {
>> + { .compatible = "rockchip,sfc"},
>> + { /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(of, rockchip_sfc_dt_ids);
>> +
>> +static struct platform_driver rockchip_sfc_driver = {
>> + .driver = {
>> + .name = "rockchip-sfc",
>> + .of_match_table = rockchip_sfc_dt_ids,
>> + },
>> + .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 is missing
sure.
>
>
>
--
Best Regards
Shawn Lin
More information about the linux-mtd
mailing list