Re: [PATCH v3 13/13] spi: atmel-quadspi: add support for sam9x60 qspi controller

Boris Brezillon
2019-02-02T07:29:33Z

On Sat, 2 Feb 2019 04:07:46 +0000
<Tudor.Ambarus@microchip.com> wrote:

> From: Tudor Ambarus <tudor.ambarus@microchip.com>
>
> The sam9x60 qspi controller uses 2 clocks, one for the peripheral register
> access, the other for the qspi core and phy. Both are mandatory. It uses
> different transfer type bits in IFR register. It has dedicated registers
> to specify a read or a write instruction: Read Instruction Code Register
> (RICR) and Write Instruction Code Register (WICR). ICR/RICR/WICR have
> identical fields.
>
> Tested with sst26vf064b jedec,spi-nor flash. Backward compatibility test
> done on sama5d2 qspi controller and mx25l25635e jedec,spi-nor flash.
>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> ---
> v3:
> - reorganize the code and change ops functions pointers to avoid code
> duplication. From the IP perspective, the transfer type bits are
> different, and what registers are written: ricr/wicr instead of icr.
> - treat just regular spi transfers. Mem transfers will be added together
> with dirmap support.
> v2:
> - rework clock handling
> - reorder setting of register values in set_cfg() calls -> move functions
> that can fail in the upper part of the function body.
>
> drivers/spi/atmel-quadspi.c | 295 +++++++++++++++++++++++++++++++++++---------
> 1 file changed, 234 insertions(+), 61 deletions(-)
>
> diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
> index c9548942535a..af1e4e25097a 100644
> --- a/drivers/spi/atmel-quadspi.c
> +++ b/drivers/spi/atmel-quadspi.c
> @@ -19,6 +19,7 @@
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/of.h>
> +#include <linux/of_platform.h>
> #include <linux/platform_device.h>
> #include <linux/spi/spi-mem.h>
>
> @@ -35,7 +36,9 @@
>
> #define QSPI_IAR 0x0030 /* Instruction Address Register */
> #define QSPI_ICR 0x0034 /* Instruction Code Register */
> +#define QSPI_WICR 0x0034 /* Write Instruction Code Register */
> #define QSPI_IFR 0x0038 /* Instruction Frame Register */
> +#define QSPI_RICR 0x003C /* Read Instruction Code Register */
>
> #define QSPI_SMR 0x0040 /* Scrambling Mode Register */
> #define QSPI_SKR 0x0044 /* Scrambling Key Register */
> @@ -88,7 +91,7 @@
> #define QSPI_SCR_DLYBS_MASK GENMASK(23, 16)
> #define QSPI_SCR_DLYBS(n) (((n) << 16) & QSPI_SCR_DLYBS_MASK)
>
> -/* Bitfields in QSPI_ICR (Instruction Code Register) */
> +/* Bitfields in QSPI_ICR (Read/Write Instruction Code Register) */
> #define QSPI_ICR_INST_MASK GENMASK(7, 0)
> #define QSPI_ICR_INST(inst) (((inst) << 0) & QSPI_ICR_INST_MASK)
> #define QSPI_ICR_OPT_MASK GENMASK(23, 16)
> @@ -117,6 +120,7 @@
> #define QSPI_IFR_CRM BIT(14)
> #define QSPI_IFR_NBDUM_MASK GENMASK(20, 16)
> #define QSPI_IFR_NBDUM(n) (((n) << 16) & QSPI_IFR_NBDUM_MASK)
> +#define QSPI_IFR_APBTFRTYP_READ BIT(24)

Maybe add a comment saying it's only available on SAM9X60 or prefix it
with SAM9X60.

>
> /* Bitfields in QSPI_SMR (Scrambling Mode Register) */
> #define QSPI_SMR_SCREN BIT(0)
> @@ -133,16 +137,39 @@
> #define QSPI_WPSR_WPVSRC(src) (((src) << 8) & QSPI_WPSR_WPVSRC)
>
>
> +/* Describes register values. */
> +struct atmel_qspi_cfg {
> + u32 icr;
> + u32 iar;
> + u32 ifr;
> +};
> +
> +struct atmel_qspi_caps;
> +
> struct atmel_qspi {
> void __iomem *regs;
> void __iomem *mem;
> struct clk *pclk;
> + struct clk *qspick;
> struct platform_device *pdev;
> + const struct atmel_qspi_caps *caps;
> u32 pending;
> u32 smm;
> struct completion cmd_completion;
> };
>
> +struct atmel_qspi_ops {
> + void (*set_tfrtyp)(const struct spi_mem_op *op,
> + struct atmel_qspi_cfg *cfg);
> + void (*write_regs)(void __iomem *base, const struct spi_mem_op *op,
> + const struct atmel_qspi_cfg *cfg);
> +};
> +
> +struct atmel_qspi_caps {
> + const struct atmel_qspi_ops *ops;
> + bool has_qspick;
> +};
> +
> struct atmel_qspi_mode {
> u8 cmd_buswidth;
> u8 addr_buswidth;
> @@ -200,30 +227,36 @@ static bool atmel_qspi_supports_op(struct spi_mem *mem,
> return true;
> }
>
> -static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
> +static int atmel_qspi_set_mode(struct atmel_qspi_cfg *cfg,
> + const struct spi_mem_op *op)
> {
> - struct atmel_qspi *aq = spi_controller_get_devdata(mem->spi->master);
> - void __iomem *base = aq->regs;
> - int mode;
> - u32 dummy_cycles = 0;
> - u32 iar, icr, ifr, sr;
> - int err = 0;
> -
> - iar = 0;
> - icr = QSPI_ICR_INST(op->cmd.opcode);
> - ifr = QSPI_IFR_INSTEN;
> + int mode = atmel_qspi_find_mode(op);
>
> - /* Set the QSPI controller in Serial Memory Mode */
> - if (aq->smm != QSPI_MR_SMM) {
> - writel_relaxed(QSPI_MR_SMM, base + QSPI_MR);
> - aq->smm = QSPI_MR_SMM;
> - }
> -
> - mode = atmel_qspi_find_mode(op);
> if (mode < 0)
> return mode;
> + cfg->ifr = sama5d2_qspi_modes[mode].config;

Looks like modes are the same for sama5d2 and sam9x60, so maybe you
should rename the sama5d2_qspi_modes variable into something more
generic.

> + return 0;
> +}
>
> - ifr |= sama5d2_qspi_modes[mode].config;
> +/*

Kernel doc headers should starts with /**, but maybe you did that on
purpose to avoid having this header parsed in case someone decides to
add this file to the list of files parsed for doc creation.

> + * atmel_qspi_set_address_mode() - set address mode.
> + * @cfg: contains register values
> + * @op: describes a SPI memory operation
> + *
> + * The controller allows 24 and 32-bit addressing while NAND-flash requires
> + * 16-bit long. Handling 8-bit long addresses is done using the option field.
> + * For the 16-bit addresses, the workaround depends of the number of requested
> + * dummy bits. If there are 8 or more dummy cycles, the address is shifted and
> + * sent with the first dummy byte. Otherwise opcode is disabled and the first
> + * byte of the address contains the command opcode (works only if the opcode and
> + * address use the same buswidth). The limitation is when the 16-bit address is
> + * used without enough dummy cycles and the opcode is using a different buswidth
> + * than the address.

This comment would better be placed directly in the function just
before the switch() statement.

> + */
> +static int atmel_qspi_set_address_mode(struct atmel_qspi_cfg *cfg,
> + const struct spi_mem_op *op)
> +{
> + u32 dummy_cycles = 0;
>
> if (op->dummy.buswidth && op->dummy.nbytes)
> dummy_cycles = op->dummy.nbytes * 8 / op->dummy.buswidth;
> @@ -233,28 +266,28 @@ static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
> case 0:
> break;
> case 1:
> - ifr |= QSPI_IFR_OPTEN | QSPI_IFR_OPTL_8BIT;
> - icr |= QSPI_ICR_OPT(op->addr.val & 0xff);
> + cfg->ifr |= QSPI_IFR_OPTEN | QSPI_IFR_OPTL_8BIT;
> + cfg->icr = QSPI_ICR_OPT(op->addr.val & 0xff);
> break;
> case 2:
> if (dummy_cycles < 8 / op->addr.buswidth) {
> - ifr &= ~QSPI_IFR_INSTEN;
> - ifr |= QSPI_IFR_ADDREN;
> - iar = (op->cmd.opcode << 16) |
> - (op->addr.val & 0xffff);
> + cfg->ifr &= ~QSPI_IFR_INSTEN;
> + cfg->ifr |= QSPI_IFR_ADDREN;
> + cfg->iar = (op->cmd.opcode << 16) |
> + (op->addr.val & 0xffff);
> } else {
> - ifr |= QSPI_IFR_ADDREN;
> - iar = (op->addr.val << 8) & 0xffffff;
> + cfg->ifr |= QSPI_IFR_ADDREN;
> + cfg->iar = (op->addr.val << 8) & 0xffffff;
> dummy_cycles -= 8 / op->addr.buswidth;
> }
> break;
> case 3:
> - ifr |= QSPI_IFR_ADDREN;
> - iar = op->addr.val & 0xffffff;
> + cfg->ifr |= QSPI_IFR_ADDREN;
> + cfg->iar = op->addr.val & 0xffffff;
> break;
> case 4:
> - ifr |= QSPI_IFR_ADDREN | QSPI_IFR_ADDRL;
> - iar = op->addr.val & 0x7ffffff;
> + cfg->ifr |= QSPI_IFR_ADDREN | QSPI_IFR_ADDRL;
> + cfg->iar = op->addr.val & 0x7ffffff;
> break;
> default:
> return -ENOTSUPP;
> @@ -263,22 +296,99 @@ static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
>
> /* Set number of dummy cycles */
> if (dummy_cycles)
> - ifr |= QSPI_IFR_NBDUM(dummy_cycles);
> + cfg->ifr |= QSPI_IFR_NBDUM(dummy_cycles);
>
> - /* Set data enable */
> - if (op->data.nbytes)
> - ifr |= QSPI_IFR_DATAEN;
> + return 0;
> +}
>
> +static void atmel_qspi_sama5d2_set_tfrtyp(const struct spi_mem_op *op,
> + struct atmel_qspi_cfg *cfg)
> +{
> if (op->data.dir == SPI_MEM_DATA_OUT)
> - ifr |= QSPI_IFR_SAMA5D2_WRITE_TRSFR;
> + cfg->ifr |= QSPI_IFR_SAMA5D2_WRITE_TRSFR;
> +}
>
> +static void atmel_qspi_sama5d2_write_regs(void __iomem *base,
> + const struct spi_mem_op *op,
> + const struct atmel_qspi_cfg *cfg)
> +{
> /* Clear pending interrupts */
> (void)readl_relaxed(base + QSPI_SR);
>
> /* Set QSPI Instruction Frame registers */
> - writel_relaxed(iar, base + QSPI_IAR);
> - writel_relaxed(icr, base + QSPI_ICR);
> - writel_relaxed(ifr, base + QSPI_IFR);
> + writel_relaxed(cfg->iar, base + QSPI_IAR);
> + writel_relaxed(cfg->icr, base + QSPI_ICR);
> + writel_relaxed(cfg->ifr, base + QSPI_IFR);
> +}
> +
> +static void atmel_qspi_sam9x60_set_tfrtyp(const struct spi_mem_op *op,
> + struct atmel_qspi_cfg *cfg)
> +{
> + if (!op->addr.nbytes && op->data.dir == SPI_MEM_DATA_IN)
> + cfg->ifr |= QSPI_IFR_APBTFRTYP_READ;
> +}
> +
> +static void atmel_qspi_sam9x60_write_regs(void __iomem *base,
> + const struct spi_mem_op *op,
> + const struct atmel_qspi_cfg *cfg)
> +{
> + /* Clear pending interrupts */
> + (void)readl_relaxed(base + QSPI_SR);
> +
> + /* Set QSPI Instruction Frame registers */
> + writel_relaxed(cfg->iar, base + QSPI_IAR);
> + if (op->data.dir == SPI_MEM_DATA_IN)
> + writel_relaxed(cfg->icr, base + QSPI_RICR);
> + else
> + writel_relaxed(cfg->icr, base + QSPI_ICR);
> + writel_relaxed(cfg->ifr, base + QSPI_IFR);
> +}
> +
> +static int atmel_qspi_set_cfg(struct atmel_qspi *aq,
> + const struct spi_mem_op *op,
> + struct atmel_qspi_cfg *cfg)
> +{
> + void __iomem *base = aq->regs;
> + int ret;
> +
> + /* Set the QSPI controller in Serial Memory Mode */
> + if (aq->smm != QSPI_MR_SMM) {
> + writel_relaxed(QSPI_MR_SMM, base + QSPI_MR);

aq->reqs +

and you can get rid of base.

> + aq->smm = QSPI_MR_SMM;
> + }
> +
> + ret = atmel_qspi_set_mode(cfg, op);
> + if (ret)
> + return ret;
> +
> + ret = atmel_qspi_set_address_mode(cfg, op);
> + if (ret)
> + return ret;
> +
> + cfg->ifr |= QSPI_IFR_INSTEN;
> + cfg->icr |= QSPI_ICR_INST(op->cmd.opcode);
> +
> + /* Set data enable */
> + if (op->data.nbytes)
> + cfg->ifr |= QSPI_IFR_DATAEN;
> +
> + aq->caps->ops->set_tfrtyp(op, cfg);
> + aq->caps->ops->write_regs(base, op, cfg);
> +
> + return 0;
> +}
> +
> +static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
> +{
> + struct atmel_qspi *aq = spi_controller_get_devdata(mem->spi->master);
> + void __iomem *base = aq->regs;
> + struct atmel_qspi_cfg cfg = {0};
> + u32 sr;
> + int err;
> +
> + err = atmel_qspi_set_cfg(aq, op, &cfg);
> + if (err)
> + return err;
>
> /* Skip to the final steps if there is no data */
> if (op->data.nbytes) {
> @@ -287,11 +397,11 @@ static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
>
> /* Send/Receive data */
> if (op->data.dir == SPI_MEM_DATA_IN)
> - _memcpy_fromio(op->data.buf.in,
> - aq->mem + iar, op->data.nbytes);
> + _memcpy_fromio(op->data.buf.in, aq->mem + cfg.iar,
> + op->data.nbytes);
> else
> - _memcpy_toio(aq->mem + iar,
> - op->data.buf.out, op->data.nbytes);
> + _memcpy_toio(aq->mem + cfg.iar, op->data.buf.out,
> + op->data.nbytes);
>
> /* Release the chip-select */
> writel_relaxed(QSPI_CR_LASTXFER, base + QSPI_CR);
> @@ -391,9 +501,22 @@ static int atmel_qspi_probe(struct platform_device *pdev)
> struct spi_controller *ctrl;
> struct atmel_qspi *aq;
> struct resource *res;
> + const struct atmel_qspi_caps *caps;
> + struct device *dev = &pdev->dev;

If you really want to do this &pdev->dev -> dev conversion (which I
don't think is necessary given that we don't have over 80 chars lines),
please do it in separate patch.

> int irq, err = 0;
>
> - ctrl = spi_alloc_master(&pdev->dev, sizeof(*aq));
> + caps = of_device_get_match_data(dev);
> + if (!caps) {
> + dev_err(dev, "Could not retrieve QSPI caps\n");
> + return -EINVAL;
> + }
> +
> + if (!caps->ops->set_tfrtyp || !caps->ops->write_regs) {
> + dev_err(dev, "Could not retrieve QSPI ops\n");
> + return -EINVAL;
> + }
> +
> + ctrl = spi_alloc_master(dev, sizeof(*aq));
> if (!ctrl)
> return -ENOMEM;
>
> @@ -409,32 +532,33 @@ static int atmel_qspi_probe(struct platform_device *pdev)
>
> init_completion(&aq->cmd_completion);
> aq->pdev = pdev;
> + aq->caps = caps;
>
> /* Map the registers */
> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_base");
> - aq->regs = devm_ioremap_resource(&pdev->dev, res);
> + aq->regs = devm_ioremap_resource(dev, res);
> if (IS_ERR(aq->regs)) {
> - dev_err(&pdev->dev, "missing registers\n");
> + dev_err(dev, "missing registers\n");
> err = PTR_ERR(aq->regs);
> goto exit;
> }
>
> /* Map the AHB memory */
> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "qspi_mmap");
> - aq->mem = devm_ioremap_resource(&pdev->dev, res);
> + aq->mem = devm_ioremap_resource(dev, res);
> if (IS_ERR(aq->mem)) {
> - dev_err(&pdev->dev, "missing AHB memory\n");
> + dev_err(dev, "missing AHB memory\n");
> err = PTR_ERR(aq->mem);
> goto exit;
> }
>
> /* Get the peripheral clock */
> - aq->pclk = devm_clk_get(&pdev->dev, "pclk");
> + aq->pclk = devm_clk_get(dev, "pclk");
> if (IS_ERR(aq->pclk))
> - aq->pclk = devm_clk_get(&pdev->dev, NULL);
> + aq->pclk = devm_clk_get(dev, NULL);
>
> if (IS_ERR(aq->pclk)) {
> - dev_err(&pdev->dev, "missing peripheral clock\n");
> + dev_err(dev, "missing peripheral clock\n");
> err = PTR_ERR(aq->pclk);
> goto exit;
> }
> @@ -442,32 +566,52 @@ static int atmel_qspi_probe(struct platform_device *pdev)
> /* Enable the peripheral clock */
> err = clk_prepare_enable(aq->pclk);
> if (err) {
> - dev_err(&pdev->dev, "failed to enable the peripheral clock\n");
> + dev_err(dev, "failed to enable the peripheral clock\n");
> goto exit;
> }
>
> + if (caps->has_qspick) {
> + /* Get the QSPI system clock */
> + aq->qspick = devm_clk_get(dev, "qspick");
> + if (IS_ERR(aq->qspick)) {
> + dev_err(dev, "missing system clock\n");
> + err = PTR_ERR(aq->qspick);
> + goto disable_pclk;
> + }
> +
> + /* Enable the QSPI system clock */
> + err = clk_prepare_enable(aq->qspick);
> + if (err) {
> + dev_err(dev,
> + "failed to enable the QSPI system clock\n");
> + goto disable_pclk;
> + }
> + }
> +
> /* Request the IRQ */
> irq = platform_get_irq(pdev, 0);
> if (irq < 0) {
> - dev_err(&pdev->dev, "missing IRQ\n");
> + dev_err(dev, "missing IRQ\n");
> err = irq;
> - goto disable_pclk;
> + goto disable_qspick;
> }
> - err = devm_request_irq(&pdev->dev, irq, atmel_qspi_interrupt,
> - 0, dev_name(&pdev->dev), aq);
> + err = devm_request_irq(dev, irq, atmel_qspi_interrupt, 0,
> + dev_name(dev), aq);
> if (err)
> - goto disable_pclk;
> + goto disable_qspick;
>
> err = atmel_qspi_init(aq);
> if (err)
> - goto disable_pclk;
> + goto disable_qspick;
>
> err = spi_register_controller(ctrl);
> if (err)
> - goto disable_pclk;
> + goto disable_qspick;
>
> return 0;
>
> +disable_qspick:
> + clk_disable_unprepare(aq->qspick);
> disable_pclk:
> clk_disable_unprepare(aq->pclk);
> exit:
> @@ -483,6 +627,7 @@ static int atmel_qspi_remove(struct platform_device *pdev)
>
> spi_unregister_controller(ctrl);
> writel_relaxed(QSPI_CR_QSPIDIS, aq->regs + QSPI_CR);
> + clk_disable_unprepare(aq->qspick);
> clk_disable_unprepare(aq->pclk);
> return 0;
> }
> @@ -491,6 +636,7 @@ static int __maybe_unused atmel_qspi_suspend(struct device *dev)
> {
> struct atmel_qspi *aq = dev_get_drvdata(dev);
>
> + clk_disable_unprepare(aq->qspick);
> clk_disable_unprepare(aq->pclk);
>
> return 0;
> @@ -501,6 +647,7 @@ static int __maybe_unused atmel_qspi_resume(struct device *dev)
> struct atmel_qspi *aq = dev_get_drvdata(dev);
>
> clk_prepare_enable(aq->pclk);
> + clk_prepare_enable(aq->qspick);
>
> return atmel_qspi_init(aq);
> }
> @@ -508,8 +655,34 @@ static int __maybe_unused atmel_qspi_resume(struct device *dev)
> static SIMPLE_DEV_PM_OPS(atmel_qspi_pm_ops, atmel_qspi_suspend,
> atmel_qspi_resume);
>
> +static const struct atmel_qspi_ops atmel_sama5d2_qspi_ops = {
> + .set_tfrtyp = atmel_qspi_sama5d2_set_tfrtyp,
> + .write_regs = atmel_qspi_sama5d2_write_regs,
> +};
> +
> +static const struct atmel_qspi_caps atmel_sama5d2_qspi_caps = {
> + .ops = &atmel_sama5d2_qspi_ops,
> +};
> +
> +static const struct atmel_qspi_ops atmel_sam9x60_qspi_ops = {
> + .set_tfrtyp = atmel_qspi_sam9x60_set_tfrtyp,
> + .write_regs = atmel_qspi_sam9x60_write_regs,
> +};
> +
> +static const struct atmel_qspi_caps atmel_sam9x60_qspi_caps = {
> + .ops = &atmel_sam9x60_qspi_ops,
> + .has_qspick = true,
> +};
> +
> static const struct of_device_id atmel_qspi_dt_ids[] = {
> - { .compatible = "atmel,sama5d2-qspi" },
> + {
> + .compatible = "atmel,sama5d2-qspi",
> + .data = &atmel_sama5d2_qspi_caps,
> + },
> + {
> + .compatible = "microchip,sam9x60-qspi",
> + .data = &atmel_sam9x60_qspi_caps,
> + },
> { /* sentinel */ }
> };
>