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Message-ID: <1738897e-7d77-aecd-cc36-6a0fb32fc121@linux.intel.com>
Date: Fri, 23 Aug 2019 13:18:59 +0800
From: "Ramuthevar, Vadivel MuruganX"
<vadivel.muruganx.ramuthevar@...ux.intel.com>
To: Vignesh Raghavendra <vigneshr@...com>,
linux-mtd@...ts.infradead.org
Cc: devicetree@...r.kernel.org, boris.brezillon@...e-electrons.com,
richard@....at, linux-kernel@...r.kernel.org,
david.oberhollenzer@...ma-star.at, jwboyer@...il.com,
computersforpeace@...il.com, dwmw2@...radead.org,
cyrille.pitchen@...el.com
Subject: Re: [PATCH v1 2/2] mtd: spi-nor: cadence-quadspi: disable the DMA,
DAC and auto poll
Hi Vignesh,
On 22/8/2019 5:03 PM, Vignesh Raghavendra wrote:
> Hi,
>
> On 19/08/19 5:24 PM, Ramuthevar, Vadivel MuruganX wrote:
>> From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@...ux.intel.com>
>>
>> On Intel Lightening Mountain(LGM) SoCs QSPI controller do not use
> s/Lightening/Lightning
Thank you so much for the review comments and your time.
(Intel -> Intel's , Lightening -> Lightning) will update
>> Direct Memory Access(DMA), Direct Access Controller(DAC) and
>> auto-poll features. This patch introduces to properly disable DMA,
>> DAC for data transfer instead it uses indirect data transfer.
>> and also auto polling.
>>
> Please split into two patch, one disabling DAC mode and DMA and other
> disabling auto polling feature.
Agreed!
>> Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@...ux.intel.com>
>> ---
>> drivers/mtd/spi-nor/Kconfig | 2 +-
>> drivers/mtd/spi-nor/cadence-quadspi.c | 62 ++++++++++++++++++++++++++++++-----
>> 2 files changed, 55 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
>> index 6de83277ce8b..ba2e372ae514 100644
>> --- a/drivers/mtd/spi-nor/Kconfig
>> +++ b/drivers/mtd/spi-nor/Kconfig
>> @@ -34,7 +34,7 @@ config SPI_ASPEED_SMC
>>
>> config SPI_CADENCE_QUADSPI
>> tristate "Cadence Quad SPI controller"
>> - depends on OF && (ARM || ARM64 || COMPILE_TEST)
>> + depends on OF && (ARM || ARM64 || COMPILE_TEST || X86)
>> help
>> Enable support for the Cadence Quad SPI Flash controller.
>>
>> diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
>> index 67f15a1f16fd..83ae28e055f4 100644
>> --- a/drivers/mtd/spi-nor/cadence-quadspi.c
>> +++ b/drivers/mtd/spi-nor/cadence-quadspi.c
>> @@ -67,6 +67,7 @@ struct cqspi_st {
>>
>> void __iomem *iobase;
>> void __iomem *ahb_base;
>> + resource_size_t ahb_phy_addr;
> What does this represent? trigger address to be programmed in
> CQSPI_REG_INDIRECTTRIGGER reg? If so why not use cdns,trigger-address
> property?
indirect operations are controlled and triggered by software via
specific APB control/configuration registers instead of AHB access to
flash data.
Yes , sure will use the trigger-address property.
>> resource_size_t ahb_size;
>> struct completion transfer_complete;
>> struct mutex bus_mutex;
>> @@ -134,6 +135,8 @@ struct cqspi_driver_platdata {
>> #define CQSPI_REG_RD_INSTR_TYPE_DATA_MASK 0x3
>> #define CQSPI_REG_RD_INSTR_DUMMY_MASK 0x1F
>>
>> +#define CQSPI_REG_WR_COMPLETION_CTRL 0x38
>> +#define CQSPI_REG_WR_COMPLETION_DISABLE_AUTO_POLL BIT(14)
>> #define CQSPI_REG_WR_INSTR 0x08
>> #define CQSPI_REG_WR_INSTR_OPCODE_LSB 0
>> #define CQSPI_REG_WR_INSTR_TYPE_ADDR_LSB 12
>> @@ -214,6 +217,7 @@ struct cqspi_driver_platdata {
>> #define CQSPI_REG_INDIRECTWRWATERMARK 0x74
>> #define CQSPI_REG_INDIRECTWRSTARTADDR 0x78
>> #define CQSPI_REG_INDIRECTWRBYTES 0x7C
>> +#define CQSPI_REG_INDIRECTTRIGGERADDRRANGE 0x80
>>
> Where is this used? Lets not add defines without a code snippet using it.
agreed, remove it.
>> #define CQSPI_REG_CMDADDRESS 0x94
>> #define CQSPI_REG_CMDREADDATALOWER 0xA0
>> @@ -470,6 +474,18 @@ static int cqspi_command_write_addr(struct spi_nor *nor,
>> return cqspi_exec_flash_cmd(cqspi, reg);
>> }
>>
>> +static int cqspi_disable_auto_poll(struct cqspi_st *cqspi)
>> +{
>> + void __iomem *reg_base = cqspi->iobase;
>> + unsigned int reg;
>> +
>> + reg = readl(reg_base + CQSPI_REG_WR_COMPLETION_CTRL);
>> + reg |= CQSPI_REG_WR_COMPLETION_DISABLE_AUTO_POLL;
>> + writel(reg, reg_base + CQSPI_REG_WR_COMPLETION_CTRL);
>> +
>> + return 0;
>> +}
>> +
>> static int cqspi_read_setup(struct spi_nor *nor)
>> {
>> struct cqspi_flash_pdata *f_pdata = nor->priv;
>> @@ -507,6 +523,11 @@ static int cqspi_read_setup(struct spi_nor *nor)
>> reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
>> reg |= (nor->addr_width - 1);
>> writel(reg, reg_base + CQSPI_REG_SIZE);
>> +
>> + /* Disable auto-polling */
>> + if (!f_pdata->use_direct_mode)
>> + cqspi_disable_auto_poll(cqspi);
>> +
> This is a one time setup. So move this to cqspi_controller_init(). More
> comments at the end of the patch
Agreed
>> return 0;
>> }
>>
>> @@ -517,12 +538,16 @@ static int cqspi_indirect_read_execute(struct spi_nor *nor, u8 *rxbuf,
>> struct cqspi_st *cqspi = f_pdata->cqspi;
>> void __iomem *reg_base = cqspi->iobase;
>> void __iomem *ahb_base = cqspi->ahb_base;
>> + resource_size_t ahb_phy_addr = cqspi->ahb_phy_addr;
>> unsigned int remaining = n_rx;
>> unsigned int mod_bytes = n_rx % 4;
>> unsigned int bytes_to_read = 0;
>> u8 *rxbuf_end = rxbuf + n_rx;
>> int ret = 0;
>>
>> + if (!f_pdata->use_direct_mode)
>> + writel(ahb_phy_addr, reg_base + CQSPI_REG_INDIRECTTRIGGER);
>> +
> Drop this and use cdns,trigger-address DT property which takes care of
> programming CQSPI_REG_INDIRECTTRIGGER in cqspi_controller_init()
Agreed
>> writel(from_addr, reg_base + CQSPI_REG_INDIRECTRDSTARTADDR);
>> writel(remaining, reg_base + CQSPI_REG_INDIRECTRDBYTES);
>>
>> @@ -609,6 +634,14 @@ static int cqspi_write_setup(struct spi_nor *nor)
>> struct cqspi_st *cqspi = f_pdata->cqspi;
>> void __iomem *reg_base = cqspi->iobase;
>>
>> + /* Disable the DMA and direct access controller */
>> + if (!f_pdata->use_direct_mode) {
>> + reg = readl(reg_base + CQSPI_REG_CONFIG);
>> + reg &= ~CQSPI_REG_CONFIG_ENB_DIR_ACC_CTRL;
>> + reg &= ~CQSPI_REG_CONFIG_DMA_MASK;
> DMA is disabled by default right? No need to clear it explicitly.
On Intel LGM SoC there is no DMA, in-case of it if enabled , system may
crash that is the reason, we are disabling it.
Let me double confirm the code changes and validate on platform.
>> + writel(reg, reg_base + CQSPI_REG_CONFIG);
>> + }
>> +
> And Move this hunk to cqspi_controller_init()
Sure
>> /* Set opcode. */
>> reg = nor->program_opcode << CQSPI_REG_WR_INSTR_OPCODE_LSB;
>> writel(reg, reg_base + CQSPI_REG_WR_INSTR);
>> @@ -619,6 +652,11 @@ static int cqspi_write_setup(struct spi_nor *nor)
>> reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
>> reg |= (nor->addr_width - 1);
>> writel(reg, reg_base + CQSPI_REG_SIZE);
>> +
>> + /* Disable auto-polling */
>> + if (!f_pdata->use_direct_mode)
>> + cqspi_disable_auto_poll(cqspi);
>> +
>> return 0;
>> }
>>
>> @@ -1165,13 +1203,16 @@ static int cqspi_of_get_pdata(struct platform_device *pdev)
>> return -ENXIO;
>> }
>>
>> - if (of_property_read_u32(np, "cdns,trigger-address",
>> - &cqspi->trigger_address)) {
>> - dev_err(&pdev->dev, "couldn't determine trigger-address\n");
>> - return -ENXIO;
>> - }
>> + if (!of_device_is_compatible(np, "intel,lgm-qspi")) {
>> + if (of_property_read_u32(np, "cdns,trigger-address",
>> + &cqspi->trigger_address)) {
>> + dev_err(&pdev->dev,
>> + "couldn't determine trigger-address\n");
>> + return -ENXIO;
>> + }
>>
> Why? Can you populate cdns,trigger-address with same address as
> res_ahb->start? That should eliminate need for cqspi->ahb_phy_addr
functionality not worked during the development time, better check and
validate, try to use
the same available as you have suggested.
>> - cqspi->rclk_en = of_property_read_bool(np, "cdns,rclk-en");
>> + cqspi->rclk_en = of_property_read_bool(np, "cdns,rclk-en");
>> + }
>>
>> return 0;
>> }
>> @@ -1301,7 +1342,8 @@ static int cqspi_setup_flash(struct cqspi_st *cqspi, struct device_node *np)
>> f_pdata->registered = true;
>>
>> if (mtd->size <= cqspi->ahb_size) {
>> - f_pdata->use_direct_mode = true;
>> + f_pdata->use_direct_mode =
>> + !(of_device_is_compatible(np, "intel,lgm-qspi"));
> Instead, introduce a new quirk (similar to CQSPI_NEEDS_WR_DELAY) and
> then use the flag to determine when to set use_direct_mode flag. Flag
> can also be used to disable DAC mode in cqspi_controller_init().
>
> And also use cqspi_driver_platdata to populate quirks for the compatible
Agreed
>> dev_dbg(nor->dev, "using direct mode for %s\n",
>> mtd->name);
>>
>> @@ -1347,7 +1389,10 @@ static int cqspi_probe(struct platform_device *pdev)
>> }
>>
>> /* Obtain QSPI clock. */
>> - cqspi->clk = devm_clk_get(dev, NULL);
>> + if (of_device_is_compatible(np, "intel,lgm-qspi"))
>> + cqspi->clk = devm_clk_get(dev, "qspi");
>> + else
>> + cqspi->clk = devm_clk_get(dev, NULL);
> Does IP have more than 1 clock input? If yes, please document all input
> clk names in Documentation/devicetree/bindings/mtd/cadence-quadspi.txt.
>
> Also, can be simplified to:
>
> cqspi->clk = devm_clk_get(dev, "qspi");
> if (IS_ERR(cqspi->clk))
> /* Try w/o clk id */
> cqspi->clk = devm_clk_get(dev, NULL);
>
> If there is only one clk input in DT, then just drop above code.
IP need only one clock.
will update and address your comments in next version patch-set.
---
With Best Regards
Vadivel Murugan
>> if (IS_ERR(cqspi->clk)) {
>> dev_err(dev, "Cannot claim QSPI clock.\n");
>> return PTR_ERR(cqspi->clk);
>> @@ -1369,6 +1414,7 @@ static int cqspi_probe(struct platform_device *pdev)
>> return PTR_ERR(cqspi->ahb_base);
>> }
>> cqspi->mmap_phys_base = (dma_addr_t)res_ahb->start;
>> + cqspi->ahb_phy_addr = res_ahb->start;
>> cqspi->ahb_size = resource_size(res_ahb);
>>
>> init_completion(&cqspi->transfer_complete);
>>
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