From c955a0cc8a286e5da1ebb88c19201e9bab8c2422 Mon Sep 17 00:00:00 2001 From: Patrice Chotard Date: Tue, 18 May 2021 18:27:52 +0200 Subject: spi: spi-mem: add automatic poll status functions With STM32 QSPI, it is possible to poll the status register of the device. This could be done to offload the CPU during an operation (erase or program a SPI NAND for example). spi_mem_poll_status API has been added to handle this feature. This new function take care of the offload/non-offload cases. For the non-offload case, use read_poll_timeout() to poll the status in order to release CPU during this phase. For example, previously, when erasing large area, in non-offload case, CPU load can reach ~50%, now it decrease to ~35%. Signed-off-by: Patrice Chotard Signed-off-by: Christophe Kerello Reviewed-by: Boris Brezillon Link: https://lore.kernel.org/r/20210518162754.15940-2-patrice.chotard@foss.st.com Signed-off-by: Mark Brown --- drivers/spi/spi-mem.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) (limited to 'drivers/spi') diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c index 1513553e4080..177b3e21febf 100644 --- a/drivers/spi/spi-mem.c +++ b/drivers/spi/spi-mem.c @@ -6,6 +6,7 @@ * Author: Boris Brezillon */ #include +#include #include #include #include @@ -743,6 +744,91 @@ static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv) return container_of(drv, struct spi_mem_driver, spidrv.driver); } +static int spi_mem_read_status(struct spi_mem *mem, + const struct spi_mem_op *op, + u16 *status) +{ + const u8 *bytes = (u8 *)op->data.buf.in; + int ret; + + ret = spi_mem_exec_op(mem, op); + if (ret) + return ret; + + if (op->data.nbytes > 1) + *status = ((u16)bytes[0] << 8) | bytes[1]; + else + *status = bytes[0]; + + return 0; +} + +/** + * spi_mem_poll_status() - Poll memory device status + * @mem: SPI memory device + * @op: the memory operation to execute + * @mask: status bitmask to ckeck + * @match: (status & mask) expected value + * @initial_delay_us: delay in us before starting to poll + * @polling_delay_us: time to sleep between reads in us + * @timeout_ms: timeout in milliseconds + * + * This function polls a status register and returns when + * (status & mask) == match or when the timeout has expired. + * + * Return: 0 in case of success, -ETIMEDOUT in case of error, + * -EOPNOTSUPP if not supported. + */ +int spi_mem_poll_status(struct spi_mem *mem, + const struct spi_mem_op *op, + u16 mask, u16 match, + unsigned long initial_delay_us, + unsigned long polling_delay_us, + u16 timeout_ms) +{ + struct spi_controller *ctlr = mem->spi->controller; + int ret = -EOPNOTSUPP; + int read_status_ret; + u16 status; + + if (op->data.nbytes < 1 || op->data.nbytes > 2 || + op->data.dir != SPI_MEM_DATA_IN) + return -EINVAL; + + if (ctlr->mem_ops && ctlr->mem_ops->poll_status) { + ret = spi_mem_access_start(mem); + if (ret) + return ret; + + ret = ctlr->mem_ops->poll_status(mem, op, mask, match, + initial_delay_us, polling_delay_us, + timeout_ms); + + spi_mem_access_end(mem); + } + + if (ret == -EOPNOTSUPP) { + if (!spi_mem_supports_op(mem, op)) + return ret; + + if (initial_delay_us < 10) + udelay(initial_delay_us); + else + usleep_range((initial_delay_us >> 2) + 1, + initial_delay_us); + + ret = read_poll_timeout(spi_mem_read_status, read_status_ret, + (read_status_ret || ((status) & mask) == match), + polling_delay_us, timeout_ms * 1000, false, mem, + op, &status); + if (read_status_ret) + return read_status_ret; + } + + return ret; +} +EXPORT_SYMBOL_GPL(spi_mem_poll_status); + static int spi_mem_probe(struct spi_device *spi) { struct spi_mem_driver *memdrv = to_spi_mem_drv(spi->dev.driver); -- cgit v1.2.3 From 86d1c6bbae32122c5f703b2d8acccf5d4258f2bb Mon Sep 17 00:00:00 2001 From: Patrice Chotard Date: Tue, 18 May 2021 18:27:54 +0200 Subject: spi: stm32-qspi: add automatic poll status feature STM32 QSPI is able to automatically poll a specified register inside the memory and relieve the CPU from this task. As example, when erasing a large memory area, we got cpu load equal to 50%. This patch allows to perform the same operation with a cpu load around 2%. Signed-off-by: Christophe Kerello Signed-off-by: Patrice Chotard Link: https://lore.kernel.org/r/20210518162754.15940-4-patrice.chotard@foss.st.com Signed-off-by: Mark Brown --- drivers/spi/spi-stm32-qspi.c | 86 +++++++++++++++++++++++++++++++++++++++----- 1 file changed, 78 insertions(+), 8 deletions(-) (limited to 'drivers/spi') diff --git a/drivers/spi/spi-stm32-qspi.c b/drivers/spi/spi-stm32-qspi.c index 7e640ccc7e77..69fd220a2894 100644 --- a/drivers/spi/spi-stm32-qspi.c +++ b/drivers/spi/spi-stm32-qspi.c @@ -36,6 +36,7 @@ #define CR_FTIE BIT(18) #define CR_SMIE BIT(19) #define CR_TOIE BIT(20) +#define CR_APMS BIT(22) #define CR_PRESC_MASK GENMASK(31, 24) #define QSPI_DCR 0x04 @@ -53,6 +54,7 @@ #define QSPI_FCR 0x0c #define FCR_CTEF BIT(0) #define FCR_CTCF BIT(1) +#define FCR_CSMF BIT(3) #define QSPI_DLR 0x10 @@ -107,6 +109,7 @@ struct stm32_qspi { u32 clk_rate; struct stm32_qspi_flash flash[STM32_QSPI_MAX_NORCHIP]; struct completion data_completion; + struct completion match_completion; u32 fmode; struct dma_chan *dma_chtx; @@ -115,6 +118,7 @@ struct stm32_qspi { u32 cr_reg; u32 dcr_reg; + unsigned long status_timeout; /* * to protect device configuration, could be different between @@ -128,11 +132,20 @@ static irqreturn_t stm32_qspi_irq(int irq, void *dev_id) struct stm32_qspi *qspi = (struct stm32_qspi *)dev_id; u32 cr, sr; + cr = readl_relaxed(qspi->io_base + QSPI_CR); sr = readl_relaxed(qspi->io_base + QSPI_SR); + if (cr & CR_SMIE && sr & SR_SMF) { + /* disable irq */ + cr &= ~CR_SMIE; + writel_relaxed(cr, qspi->io_base + QSPI_CR); + complete(&qspi->match_completion); + + return IRQ_HANDLED; + } + if (sr & (SR_TEF | SR_TCF)) { /* disable irq */ - cr = readl_relaxed(qspi->io_base + QSPI_CR); cr &= ~CR_TCIE & ~CR_TEIE; writel_relaxed(cr, qspi->io_base + QSPI_CR); complete(&qspi->data_completion); @@ -319,6 +332,24 @@ out: return err; } +static int stm32_qspi_wait_poll_status(struct stm32_qspi *qspi, + const struct spi_mem_op *op) +{ + u32 cr; + + reinit_completion(&qspi->match_completion); + cr = readl_relaxed(qspi->io_base + QSPI_CR); + writel_relaxed(cr | CR_SMIE, qspi->io_base + QSPI_CR); + + if (!wait_for_completion_timeout(&qspi->match_completion, + msecs_to_jiffies(qspi->status_timeout))) + return -ETIMEDOUT; + + writel_relaxed(FCR_CSMF, qspi->io_base + QSPI_FCR); + + return 0; +} + static int stm32_qspi_get_mode(struct stm32_qspi *qspi, u8 buswidth) { if (buswidth == 4) @@ -332,7 +363,7 @@ static int stm32_qspi_send(struct spi_mem *mem, const struct spi_mem_op *op) struct stm32_qspi *qspi = spi_controller_get_devdata(mem->spi->master); struct stm32_qspi_flash *flash = &qspi->flash[mem->spi->chip_select]; u32 ccr, cr; - int timeout, err = 0; + int timeout, err = 0, err_poll_status = 0; dev_dbg(qspi->dev, "cmd:%#x mode:%d.%d.%d.%d addr:%#llx len:%#x\n", op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth, @@ -378,6 +409,9 @@ static int stm32_qspi_send(struct spi_mem *mem, const struct spi_mem_op *op) if (op->addr.nbytes && qspi->fmode != CCR_FMODE_MM) writel_relaxed(op->addr.val, qspi->io_base + QSPI_AR); + if (qspi->fmode == CCR_FMODE_APM) + err_poll_status = stm32_qspi_wait_poll_status(qspi, op); + err = stm32_qspi_tx(qspi, op); /* @@ -387,7 +421,7 @@ static int stm32_qspi_send(struct spi_mem *mem, const struct spi_mem_op *op) * byte of device (device size - fifo size). like device size is not * knows, the prefetching is always stop. */ - if (err || qspi->fmode == CCR_FMODE_MM) + if (err || err_poll_status || qspi->fmode == CCR_FMODE_MM) goto abort; /* wait end of tx in indirect mode */ @@ -406,15 +440,49 @@ abort: cr, !(cr & CR_ABORT), 1, STM32_ABT_TIMEOUT_US); - writel_relaxed(FCR_CTCF, qspi->io_base + QSPI_FCR); + writel_relaxed(FCR_CTCF | FCR_CSMF, qspi->io_base + QSPI_FCR); - if (err || timeout) - dev_err(qspi->dev, "%s err:%d abort timeout:%d\n", - __func__, err, timeout); + if (err || err_poll_status || timeout) + dev_err(qspi->dev, "%s err:%d err_poll_status:%d abort timeout:%d\n", + __func__, err, err_poll_status, timeout); return err; } +static int stm32_qspi_poll_status(struct spi_mem *mem, const struct spi_mem_op *op, + u16 mask, u16 match, + unsigned long initial_delay_us, + unsigned long polling_rate_us, + unsigned long timeout_ms) +{ + struct stm32_qspi *qspi = spi_controller_get_devdata(mem->spi->master); + int ret; + + if (!spi_mem_supports_op(mem, op)) + return -EOPNOTSUPP; + + ret = pm_runtime_get_sync(qspi->dev); + if (ret < 0) { + pm_runtime_put_noidle(qspi->dev); + return ret; + } + + mutex_lock(&qspi->lock); + + writel_relaxed(mask, qspi->io_base + QSPI_PSMKR); + writel_relaxed(match, qspi->io_base + QSPI_PSMAR); + qspi->fmode = CCR_FMODE_APM; + qspi->status_timeout = timeout_ms; + + ret = stm32_qspi_send(mem, op); + mutex_unlock(&qspi->lock); + + pm_runtime_mark_last_busy(qspi->dev); + pm_runtime_put_autosuspend(qspi->dev); + + return ret; +} + static int stm32_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) { struct stm32_qspi *qspi = spi_controller_get_devdata(mem->spi->master); @@ -527,7 +595,7 @@ static int stm32_qspi_setup(struct spi_device *spi) flash->presc = presc; mutex_lock(&qspi->lock); - qspi->cr_reg = 3 << CR_FTHRES_SHIFT | CR_SSHIFT | CR_EN; + qspi->cr_reg = CR_APMS | 3 << CR_FTHRES_SHIFT | CR_SSHIFT | CR_EN; writel_relaxed(qspi->cr_reg, qspi->io_base + QSPI_CR); /* set dcr fsize to max address */ @@ -607,6 +675,7 @@ static const struct spi_controller_mem_ops stm32_qspi_mem_ops = { .exec_op = stm32_qspi_exec_op, .dirmap_create = stm32_qspi_dirmap_create, .dirmap_read = stm32_qspi_dirmap_read, + .poll_status = stm32_qspi_poll_status, }; static int stm32_qspi_probe(struct platform_device *pdev) @@ -661,6 +730,7 @@ static int stm32_qspi_probe(struct platform_device *pdev) } init_completion(&qspi->data_completion); + init_completion(&qspi->match_completion); qspi->clk = devm_clk_get(dev, NULL); if (IS_ERR(qspi->clk)) { -- cgit v1.2.3