On 04/07/2016 04:10 AM, Jiancheng Xue wrote: > Hi Brian, > Thank you very much for your comments. I'll fix these issues in next version. > In addition, for easy understanding I'd like to rewrite hisi_spi_nor_write and > hisi_spi_nor_read. Your comments on these modifications will be highly appreciated. Would you please stop top-posting ? It rubs some people the wrong way. > static int hisi_spi_nor_read(struct spi_nor *nor, loff_t from, size_t len, > size_t *retlen, u_char *read_buf) > { > struct hifmc_priv *priv = nor->priv; > struct hifmc_host *host = priv->host; > int i; > > /* read all bytes in only one time */ > if (len <= HIFMC_DMA_MAX_LEN) { > hisi_spi_nor_dma_transfer(nor, from, host->dma_buffer, > len, FMC_OP_READ); > memcpy(read_buf, host->buffer, len); Is all the ad-hoc memcpying necessary? I think you can use dma_map_single() and co to obtain DMAble memory for your controller's use and then you can probably get rid of most of this stuff. > } else { > /* read HIFMC_DMA_MAX_LEN bytes at a time */ > for (i = 0; i < len; i += HIFMC_DMA_MAX_LEN) { > hisi_spi_nor_dma_transfer(nor, from + i, host->dma_buffer, > HIFMC_DMA_MAX_LEN, FMC_OP_READ); > memcpy(read_buf + i, host->buffer, HIFMC_DMA_MAX_LEN); > } > /* read remaining bytes */ > i -= HIFMC_DMA_MAX_LEN; > hisi_spi_nor_dma_transfer(nor, from + i, host->dma_buffer, > len - i, FMC_OP_READ); > memcpy(read_buf + i, host->buffer, len - i); > } > *retlen = len; > > return 0; > } > > Because "len" passed from spi_nor_write is smaller than nor->page_size, and nor->page_size > is smaller than the length of host->dma_buffer. We can transfer "len" bytes data by > hisi_spi_nor_dma_transfer at one time. hisi_spi_nor_write can be simplified like below: > > static void hisi_spi_nor_write(struct spi_nor *nor, loff_t to, > size_t len, size_t *retlen, const u_char *write_buf) > { > struct hifmc_priv *priv = nor->priv; > struct hifmc_host *host = priv->host; > > /* len is smaller than dma buffer length*/ > memcpy(host->buffer, write_buf, len); > hisi_spi_nor_dma_transfer(nor, to, host->dma_buffer, len, > FMC_OP_WRITE); > > *retlen = len; > } > > Regards, > Jiancheng > > On 2016/4/4 14:44, Brian Norris wrote: >> Hi Jiancheng, >> >> Looking good. In addition to Marek's comments, I have just a few small >> comments. I'll post a small diff at the end, and a few inline comments. >> >> On Mon, Mar 28, 2016 at 05:15:28PM +0800, Jiancheng Xue wrote: >>> Hi Marek, >>> Firstly, thank you very much for your comments. >>> >>> On 2016/3/27 9:47, Marek Vasut wrote: >>>> On 03/26/2016 09:11 AM, Jiancheng Xue wrote: >>>>> Add hisilicon spi-nor flash controller driver >>>>> >>>>> Signed-off-by: Binquan Peng <pengbinquan@xxxxxxxxxx> >>>>> Signed-off-by: Jiancheng Xue <xuejiancheng@xxxxxxxxxx> >>>>> Acked-by: Rob Herring <robh@xxxxxxxxxx> >>>>> Reviewed-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx> >>>>> Reviewed-by: Jagan Teki <jteki@xxxxxxxxxxxx> >>>>> --- >>>>> change log >>>>> v9: >>>>> Fixed issues pointed by Jagan Teki. >>>> >>>> It'd be really great if you could list which exact issues you fixed. >>>> >>> >>> OK. I'll describe the history log more detailed in next version. >>> >>>>> v8: >>>>> Fixed issues pointed by Ezequiel Garcia and Brian Norris. >>>>> Moved dts binding file to mtd directory. >>>>> Changed the compatible string more specific. >>>> >>>> [...] >> >> ^^ You were using <linux/of_device.h> in here, even though you don't >> need any of its contents. You just wanted <linux/of.h> and >> <linux/platform_device.h>. >> >>>> >>>>> +/* Hardware register offsets and field definitions */ >>>>> +#define FMC_CFG 0x00 >>>>> +#define SPI_NOR_ADDR_MODE BIT(10) >>>>> +#define FMC_GLOBAL_CFG 0x04 >>>>> +#define FMC_GLOBAL_CFG_WP_ENABLE BIT(6) >>>>> +#define FMC_SPI_TIMING_CFG 0x08 >>>>> +#define TIMING_CFG_TCSH(nr) (((nr) & 0xf) << 8) >>>>> +#define TIMING_CFG_TCSS(nr) (((nr) & 0xf) << 4) >>>>> +#define TIMING_CFG_TSHSL(nr) ((nr) & 0xf) >>>>> +#define CS_HOLD_TIME 0x6 >>>>> +#define CS_SETUP_TIME 0x6 >>>>> +#define CS_DESELECT_TIME 0xf >>>>> +#define FMC_INT 0x18 >>>>> +#define FMC_INT_OP_DONE BIT(0) >>>>> +#define FMC_INT_CLR 0x20 >>>>> +#define FMC_CMD 0x24 >>>>> +#define FMC_CMD_CMD1(_cmd) ((_cmd) & 0xff) >>>> >>>> Drop the underscores in the argument names. >>>> >>> OK. >>>>> +#define FMC_ADDRL 0x2c >>>>> +#define FMC_OP_CFG 0x30 >>>>> +#define OP_CFG_FM_CS(_cs) ((_cs) << 11) >>>>> +#define OP_CFG_MEM_IF_TYPE(_type) (((_type) & 0x7) << 7) >>>>> +#define OP_CFG_ADDR_NUM(_addr) (((_addr) & 0x7) << 4) >>>>> +#define OP_CFG_DUMMY_NUM(_dummy) ((_dummy) & 0xf) >>>>> +#define FMC_DATA_NUM 0x38 >>>>> +#define FMC_DATA_NUM_CNT(_n) ((_n) & 0x3fff) >>>>> +#define FMC_OP 0x3c >>>>> +#define FMC_OP_DUMMY_EN BIT(8) >>>>> +#define FMC_OP_CMD1_EN BIT(7) >>>>> +#define FMC_OP_ADDR_EN BIT(6) >>>>> +#define FMC_OP_WRITE_DATA_EN BIT(5) >>>>> +#define FMC_OP_READ_DATA_EN BIT(2) >>>>> +#define FMC_OP_READ_STATUS_EN BIT(1) >>>>> +#define FMC_OP_REG_OP_START BIT(0) >>>> >>>> [...] >>>> >>>>> +enum hifmc_iftype { >>>>> + IF_TYPE_STD, >>>>> + IF_TYPE_DUAL, >>>>> + IF_TYPE_DIO, >>>>> + IF_TYPE_QUAD, >>>>> + IF_TYPE_QIO, >>>>> +}; >>>>> + >>>>> +struct hifmc_priv { >>>>> + int chipselect; >>>> >>>> Can chipselect be set to < 0 values ? >>>> >>> The type will be changed to u32. >>> >>>>> + u32 clkrate; >>>>> + struct hifmc_host *host; >>>>> +}; >>>>> + >>>>> +#define HIFMC_MAX_CHIP_NUM 2 >>>> >>>> This does not scale very well, use dynamic allocation. >>>> >>> OK. Dynamic allocation will be used in next version. >>>>> +struct hifmc_host { >>>>> + struct device *dev; >>>>> + struct mutex lock; >>>>> + >>>>> + void __iomem *regbase; >>>>> + void __iomem *iobase; >>>>> + struct clk *clk; >>>>> + void *buffer; >>>>> + dma_addr_t dma_buffer; >>>>> + >>>>> + struct spi_nor nor[HIFMC_MAX_CHIP_NUM]; >>>>> + struct hifmc_priv priv[HIFMC_MAX_CHIP_NUM]; >>>>> + int num_chip; >>>>> +}; >>>>> + >>>>> +static inline int wait_op_finish(struct hifmc_host *host) >>>>> +{ >>>>> + unsigned int reg; >>>>> + >>>>> + return readl_poll_timeout(host->regbase + FMC_INT, reg, >>>>> + (reg & FMC_INT_OP_DONE), 0, FMC_WAIT_TIMEOUT); >>>>> +} >>>>> + >>>>> +static int get_if_type(enum read_mode flash_read) >>>>> +{ >>>>> + enum hifmc_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: >>>>> + if_type = IF_TYPE_STD; >>>>> + break; >>>>> + } >>>>> + >>>>> + return if_type; >>>>> +} >>>>> + >>>>> +static void hisi_spi_nor_init(struct hifmc_host *host) >>>>> +{ >>>>> + unsigned int reg; >>>> >>>> Should be u32 here. >>>> >>> OK. >>>>> + reg = TIMING_CFG_TCSH(CS_HOLD_TIME) >>>>> + | TIMING_CFG_TCSS(CS_SETUP_TIME) >>>>> + | TIMING_CFG_TSHSL(CS_DESELECT_TIME); >>>>> + writel(reg, host->regbase + FMC_SPI_TIMING_CFG); >>>>> +} >>>>> + >>>>> +static int hisi_spi_nor_prep(struct spi_nor *nor, enum spi_nor_ops ops) >>>>> +{ >>>>> + struct hifmc_priv *priv = nor->priv; >>>>> + struct hifmc_host *host = priv->host; >>>>> + int ret; >>>>> + >>>>> + mutex_lock(&host->lock); >>>> >>>> Why do you need the mutex lock here ? Let me guess -- SPI NOR framework >>>> locks a mutex in struct spi_nor , but that's not enough if you have >>>> multiple SPI NORs on the same bus, because concurrent access to multiple >>>> SPI NOR flashes needs locking on the controller level, right ? >>>> >>> Yes, you are quite right. The controller can connect with two SPI NOR flashes >>> on one board. This lock is used on the controller level. >> >> Yeah... we should probably implement some common controller logic in the >> core eventually. But the mutex is necessary for now. >> >>>>> + ret = clk_set_rate(host->clk, priv->clkrate); >>>>> + if (ret) >>>>> + goto out; >>>>> + >>>>> + ret = clk_prepare_enable(host->clk); >>>>> + if (ret) >>>>> + goto out; >>>>> + >>>>> + return 0; >>>>> + >>>>> +out: >>>>> + mutex_unlock(&host->lock); >>>>> + return ret; >>>>> +} >>>>> + >>>>> +static void hisi_spi_nor_unprep(struct spi_nor *nor, enum spi_nor_ops ops) >>>>> +{ >>>>> + struct hifmc_priv *priv = nor->priv; >>>>> + struct hifmc_host *host = priv->host; >>>>> + >>>>> + clk_disable_unprepare(host->clk); >>>>> + mutex_unlock(&host->lock); >>>>> +} >>>>> + >>>>> +static void hisi_spi_nor_cmd_prepare(struct hifmc_host *host, u8 cmd, >>>>> + u32 *opcfg) >>>>> +{ >>>>> + u32 reg; >>>>> + >>>>> + *opcfg |= FMC_OP_CMD1_EN; >>>>> + switch (cmd) { >>>>> + case SPINOR_OP_RDID: >>>>> + case SPINOR_OP_RDSR: >>>>> + case SPINOR_OP_RDCR: >>>>> + *opcfg |= FMC_OP_READ_DATA_EN; >>>>> + break; >>>>> + case SPINOR_OP_WREN: >>>>> + reg = readl(host->regbase + FMC_GLOBAL_CFG); >>>>> + if (reg & FMC_GLOBAL_CFG_WP_ENABLE) { >>>>> + reg &= ~FMC_GLOBAL_CFG_WP_ENABLE; >>>>> + writel(reg, host->regbase + FMC_GLOBAL_CFG); >>>>> + } >>>>> + break; >>>>> + case SPINOR_OP_WRSR: >>>>> + *opcfg |= FMC_OP_WRITE_DATA_EN; >>>>> + break; >>>>> + case SPINOR_OP_BE_4K: >>>>> + case SPINOR_OP_BE_4K_PMC: >>>>> + case SPINOR_OP_SE_4B: >>>>> + case SPINOR_OP_SE: >>>>> + *opcfg |= FMC_OP_ADDR_EN; >>>>> + break; >>>>> + case SPINOR_OP_EN4B: >>>>> + reg = readl(host->regbase + FMC_CFG); >>>>> + reg |= SPI_NOR_ADDR_MODE; >>>>> + writel(reg, host->regbase + FMC_CFG); >>>>> + break; >>>>> + case SPINOR_OP_EX4B: >>>>> + reg = readl(host->regbase + FMC_CFG); >>>>> + reg &= ~SPI_NOR_ADDR_MODE; >>>>> + writel(reg, host->regbase + FMC_CFG); >>>>> + break; >>>>> + case SPINOR_OP_CHIP_ERASE: >>>>> + default: >>>>> + break; >>>>> + } >>>> >>>> Won't the driver fail if we add new instructions into the SPI NOR core >>>> which are not handled by this huge switch statement ? >>>> >>> Only some of commands are needed to process in this stage for the controller. >>> Others have no needs. So this function won't return failure. >> >> It's not ideal to have this sort of function if we can avoid it (since >> it's hard to figure out how to extend this for new opcodes). But it >> looks necessary for now. >> >>> I'll combine SPINOR_OP_CHIP_ERASE into the default case in next version. >>> >>>>> +} >>>> >>>> [...] >>>> >>>>> +static void hisi_spi_nor_write(struct spi_nor *nor, loff_t to, >>>>> + size_t len, size_t *retlen, const u_char *write_buf) >>>>> +{ >>>>> + struct hifmc_priv *priv = nor->priv; >>>>> + struct hifmc_host *host = priv->host; >>>>> + const unsigned char *ptr = write_buf; >>>>> + size_t actual_len; >>>>> + >>>>> + *retlen = 0; >>>>> + while (len > 0) { >>>>> + if (to & HIFMC_DMA_MASK) >>>>> + actual_len = (HIFMC_DMA_MAX_LEN - (to & HIFMC_DMA_MASK)) >>>>> + >= len ? len >>>>> + : (HIFMC_DMA_MAX_LEN - (to & HIFMC_DMA_MASK)); >>>> >>>> Rewrite this as something like the following snippet, for the sake of >>>> readability: >>>> >>>> actual_len = HIFMC_DMA_MAX_LEN - (to & HIFMC_DMA_MASK); >>>> if (actual_len >= len) >>>> actual_len = len; >>>> >>> OK. Thank you. >>>>> + else >>>>> + actual_len = (len >= HIFMC_DMA_MAX_LEN) >>>>> + ? HIFMC_DMA_MAX_LEN : len; >> >> Wait, why do you need the else case? Isn't this just equivalent to the >> first case? I'd suggest consolidating these two blocks, and dropping the >> ?: entirely, since (like Marek said) it's hurting readability. So: >> >> /* Don't cross HIFMC_DMA_MAX_LEN alignment boundaries */ >> if ((HIFMC_DMA_MAX_LEN - (to & HIFMC_DMA_MASK)) >= len) >> actual_len = len; >> else >> actual_len = HIFMC_DMA_MAX_LEN - (to & HIFMC_DMA_MASK); >> >>>>> + memcpy(host->buffer, ptr, actual_len); >>>>> + hisi_spi_nor_dma_transfer(nor, to, host->dma_buffer, actual_len, >>>>> + FMC_OP_WRITE); >>>>> + to += actual_len; >>>>> + ptr += actual_len; >>>>> + len -= actual_len; >>>>> + *retlen += actual_len; >>>>> + } >>>>> +} >> >> [...] >> >> Here's my diff: >> >> diff --git a/drivers/mtd/spi-nor/hisi-sfc.c b/drivers/mtd/spi-nor/hisi-sfc.c >> index e974c92a0a25..0c58fd3b8790 100644 >> --- a/drivers/mtd/spi-nor/hisi-sfc.c >> +++ b/drivers/mtd/spi-nor/hisi-sfc.c >> @@ -16,13 +16,15 @@ >> * 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/clk.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_platform.h> >> +#include <linux/of.h> >> +#include <linux/platform_device.h> >> #include <linux/slab.h> >> >> /* Hardware register offsets and field definitions */ >> @@ -343,13 +345,11 @@ static void hisi_spi_nor_write(struct spi_nor *nor, loff_t to, >> >> *retlen = 0; >> while (len > 0) { >> - if (to & HIFMC_DMA_MASK) >> - actual_len = (HIFMC_DMA_MAX_LEN - (to & HIFMC_DMA_MASK)) >> - >= len ? len >> - : (HIFMC_DMA_MAX_LEN - (to & HIFMC_DMA_MASK)); >> + /* Don't cross HIFMC_DMA_MAX_LEN alignment boundaries */ >> + if ((HIFMC_DMA_MAX_LEN - (to & HIFMC_DMA_MASK)) >= len) >> + actual_len = len; >> else >> - actual_len = (len >= HIFMC_DMA_MAX_LEN) >> - ? HIFMC_DMA_MAX_LEN : len; >> + actual_len = HIFMC_DMA_MAX_LEN - (to & HIFMC_DMA_MASK); >> memcpy(host->buffer, ptr, actual_len); >> hisi_spi_nor_dma_transfer(nor, to, host->dma_buffer, actual_len, >> FMC_OP_WRITE); >> >> . >> > -- Best regards, Marek Vasut -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html