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Message-ID: <53dcc9a9-6adb-a1de-cfb4-11a68e5d3d4c@ti.com>
Date: Thu, 22 Aug 2019 14:33:18 +0530
From: Vignesh Raghavendra <vigneshr@...com>
To: "Ramuthevar, Vadivel MuruganX"
<vadivel.muruganx.ramuthevar@...ux.intel.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,
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
> 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.
> 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?
> 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.
> #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
> 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()
> 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.
> + writel(reg, reg_base + CQSPI_REG_CONFIG);
> + }
> +
And Move this hunk to cqspi_controller_init()
> /* 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
> - 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
> 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.
> 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);
>
--
Regards
Vignesh
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