From 794912cff6dba8b5e93948243299bb0b2cb11277 Mon Sep 17 00:00:00 2001 From: Michal Suchanek Date: Mon, 13 Jun 2016 17:46:50 +0000 Subject: [PATCH 1/6] spi: sunxi: expose maximum transfer size limit The sun4i spi hardware can trasfer at most 63 bytes of data without DMA support so report the limitation. Same for sun6i. Signed-off-by: Michal Suchanek Acked-by: Maxime Ripard Signed-off-by: Mark Brown --- drivers/spi/spi-sun4i.c | 6 ++++++ drivers/spi/spi-sun6i.c | 5 +++++ 2 files changed, 11 insertions(+) diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c index 1ddd9e2309b6..07ce7c97750e 100644 --- a/drivers/spi/spi-sun4i.c +++ b/drivers/spi/spi-sun4i.c @@ -167,6 +167,11 @@ static void sun4i_spi_set_cs(struct spi_device *spi, bool enable) sun4i_spi_write(sspi, SUN4I_CTL_REG, reg); } +static size_t sun4i_spi_max_transfer_size(struct spi_device *spi) +{ + return SUN4I_FIFO_DEPTH - 1; +} + static int sun4i_spi_transfer_one(struct spi_master *master, struct spi_device *spi, struct spi_transfer *tfr) @@ -394,6 +399,7 @@ static int sun4i_spi_probe(struct platform_device *pdev) master->bits_per_word_mask = SPI_BPW_MASK(8); master->dev.of_node = pdev->dev.of_node; master->auto_runtime_pm = true; + master->max_transfer_size = sun4i_spi_max_transfer_size; sspi->hclk = devm_clk_get(&pdev->dev, "ahb"); if (IS_ERR(sspi->hclk)) { diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c index 42e2c4bd690a..6fa6ff12ae61 100644 --- a/drivers/spi/spi-sun6i.c +++ b/drivers/spi/spi-sun6i.c @@ -153,6 +153,10 @@ static void sun6i_spi_set_cs(struct spi_device *spi, bool enable) sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg); } +static size_t sun6i_spi_max_transfer_size(struct spi_device *spi) +{ + return SUN6I_FIFO_DEPTH - 1; +} static int sun6i_spi_transfer_one(struct spi_master *master, struct spi_device *spi, @@ -393,6 +397,7 @@ static int sun6i_spi_probe(struct platform_device *pdev) master->bits_per_word_mask = SPI_BPW_MASK(8); master->dev.of_node = pdev->dev.of_node; master->auto_runtime_pm = true; + master->max_transfer_size = sun6i_spi_max_transfer_size; sspi->hclk = devm_clk_get(&pdev->dev, "ahb"); if (IS_ERR(sspi->hclk)) { From 77cca63acc444d0eee66d3631659831b6339c95e Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Thu, 23 Jun 2016 18:01:34 +0100 Subject: [PATCH 2/6] spi: ti-qspi: spelling mistake: "trasnfers" -> "transfers" trivial fix to spelling mistake in dev_dbg message Signed-off-by: Colin Ian King Signed-off-by: Mark Brown --- drivers/spi/spi-ti-qspi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c index 443f664534e1..e0e5c6aaa5cb 100644 --- a/drivers/spi/spi-ti-qspi.c +++ b/drivers/spi/spi-ti-qspi.c @@ -141,7 +141,7 @@ static int ti_qspi_setup(struct spi_device *spi) u32 clk_ctrl_reg, clk_rate, clk_mask; if (spi->master->busy) { - dev_dbg(qspi->dev, "master busy doing other trasnfers\n"); + dev_dbg(qspi->dev, "master busy doing other transfers\n"); return -EBUSY; } From 0b06d8cf4f9307887d52776d77bdbc8d6dd9d98d Mon Sep 17 00:00:00 2001 From: Michal Suchanek Date: Tue, 14 Jun 2016 12:10:04 +0000 Subject: [PATCH 3/6] spi: sunxi: set maximum and minimum speed of SPI master The speed limits are unset in the sun4i and sun6i SPI drivers. The maximum speed of SPI master is used when maximum speed of SPI slave is not specified. Also the __spi_validate function should check that transfer speeds do not exceed the master limits. The user manual for A10 and A31 specifies maximum speed of the SPI clock as 100MHz and minimum as 3kHz. Setting the SPI clock to out-of-spec values can lock up the SoC. Signed-off-by: Michal Suchanek -- v2: new patch v3: fix constant style Signed-off-by: Mark Brown --- drivers/spi/spi-sun4i.c | 2 ++ drivers/spi/spi-sun6i.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/drivers/spi/spi-sun4i.c b/drivers/spi/spi-sun4i.c index 07ce7c97750e..d02cf9829f1a 100644 --- a/drivers/spi/spi-sun4i.c +++ b/drivers/spi/spi-sun4i.c @@ -392,6 +392,8 @@ static int sun4i_spi_probe(struct platform_device *pdev) } sspi->master = master; + master->max_speed_hz = 100 * 1000 * 1000; + master->min_speed_hz = 3 * 1000; master->set_cs = sun4i_spi_set_cs; master->transfer_one = sun4i_spi_transfer_one; master->num_chipselect = 4; diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c index 6fa6ff12ae61..d5a6a2e5f54a 100644 --- a/drivers/spi/spi-sun6i.c +++ b/drivers/spi/spi-sun6i.c @@ -390,6 +390,8 @@ static int sun6i_spi_probe(struct platform_device *pdev) } sspi->master = master; + master->max_speed_hz = 100 * 1000 * 1000; + master->min_speed_hz = 3 * 1000; master->set_cs = sun6i_spi_set_cs; master->transfer_one = sun6i_spi_transfer_one; master->num_chipselect = 4; From b43afff7dc3719612dd5140fe2b0357ae1faf9b7 Mon Sep 17 00:00:00 2001 From: Bhaktipriya Shridhar Date: Sat, 2 Jul 2016 14:20:55 +0530 Subject: [PATCH 4/6] spi: spi-txx9: Remove deprecated create_singlethread_workqueue The workqueue "workqueue" has a single work item(&c->work) and hence doesn't require ordering. Also, it is not being used on a memory reclaim path. Hence, the singlethreaded workqueue has been replaced with the use of system_wq. System workqueues have been able to handle high level of concurrency for a long time now and hence it's not required to have a singlethreaded workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue created with create_singlethread_workqueue(), system_wq allows multiple work items to overlap executions even on the same CPU; however, a per-cpu workqueue doesn't have any CPU locality or global ordering guarantee unless the target CPU is explicitly specified and thus the increase of local concurrency shouldn't make any difference. Work item has been flushed in txx9spi_remove() to ensure that nothing is pending while disconnecting the driver. Signed-off-by: Bhaktipriya Shridhar Acked-by: Tejun Heo Signed-off-by: Mark Brown --- drivers/spi/spi-txx9.c | 11 ++--------- 1 file changed, 2 insertions(+), 9 deletions(-) diff --git a/drivers/spi/spi-txx9.c b/drivers/spi/spi-txx9.c index d69f8f8f3fa6..7492ea346b43 100644 --- a/drivers/spi/spi-txx9.c +++ b/drivers/spi/spi-txx9.c @@ -72,7 +72,6 @@ struct txx9spi { - struct workqueue_struct *workqueue; struct work_struct work; spinlock_t lock; /* protect 'queue' */ struct list_head queue; @@ -315,7 +314,7 @@ static int txx9spi_transfer(struct spi_device *spi, struct spi_message *m) spin_lock_irqsave(&c->lock, flags); list_add_tail(&m->queue, &c->queue); - queue_work(c->workqueue, &c->work); + schedule_work(&c->work); spin_unlock_irqrestore(&c->lock, flags); return 0; @@ -374,10 +373,6 @@ static int txx9spi_probe(struct platform_device *dev) if (ret) goto exit; - c->workqueue = create_singlethread_workqueue( - dev_name(master->dev.parent)); - if (!c->workqueue) - goto exit_busy; c->last_chipselect = -1; dev_info(&dev->dev, "at %#llx, irq %d, %dMHz\n", @@ -400,8 +395,6 @@ static int txx9spi_probe(struct platform_device *dev) exit_busy: ret = -EBUSY; exit: - if (c->workqueue) - destroy_workqueue(c->workqueue); clk_disable(c->clk); spi_master_put(master); return ret; @@ -412,7 +405,7 @@ static int txx9spi_remove(struct platform_device *dev) struct spi_master *master = platform_get_drvdata(dev); struct txx9spi *c = spi_master_get_devdata(master); - destroy_workqueue(c->workqueue); + flush_work(&c->work); clk_disable(c->clk); return 0; } From cf9f4327a306be58df6c0b3817d7ef06a2a3da03 Mon Sep 17 00:00:00 2001 From: Mika Westerberg Date: Mon, 4 Jul 2016 17:18:15 +0300 Subject: [PATCH 5/6] spi: spidev: Add ACPI probing support Some IoT and maker software stacks are using spidev to perform raw access to the SPI bus instead of relying existing drivers provided by the kernel. They then implement their own "drivers" in userspace on top of the spidev raw interface. This is far from being an ideal solution but we do not want to prevent using mainline Linux in these devices. Now, it turns out that Windows has similar SPI devices than spidev which allow raw access on the SPI bus to userspace programs as described in the link below: https://msdn.microsoft.com/windows/hardware/drivers/spb/spi-tests-in-mitt These SPI test devices are also meant to be used during development and testing. In order to allow usage of spidev for development and testing in Linux, add those same ACPI IDs to the spidev driver (which is Linux counterpart of the Windows SPI test devices), but complain loudly so that users know it is not good idea to use it in production systems. Instead they should be using proper drivers for peripherals connected to the SPI bus. Signed-off-by: Mika Westerberg Signed-off-by: Mark Brown --- drivers/spi/spidev.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c index e3c19f30f591..2e05046f866b 100644 --- a/drivers/spi/spidev.c +++ b/drivers/spi/spidev.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include @@ -700,6 +701,43 @@ static const struct of_device_id spidev_dt_ids[] = { MODULE_DEVICE_TABLE(of, spidev_dt_ids); #endif +#ifdef CONFIG_ACPI + +/* Dummy SPI devices not to be used in production systems */ +#define SPIDEV_ACPI_DUMMY 1 + +static const struct acpi_device_id spidev_acpi_ids[] = { + /* + * The ACPI SPT000* devices are only meant for development and + * testing. Systems used in production should have a proper ACPI + * description of the connected peripheral and they should also use + * a proper driver instead of poking directly to the SPI bus. + */ + { "SPT0001", SPIDEV_ACPI_DUMMY }, + { "SPT0002", SPIDEV_ACPI_DUMMY }, + { "SPT0003", SPIDEV_ACPI_DUMMY }, + {}, +}; +MODULE_DEVICE_TABLE(acpi, spidev_acpi_ids); + +static void spidev_probe_acpi(struct spi_device *spi) +{ + const struct acpi_device_id *id; + + if (!has_acpi_companion(&spi->dev)) + return; + + id = acpi_match_device(spidev_acpi_ids, &spi->dev); + if (WARN_ON(!id)) + return; + + if (id->driver_data == SPIDEV_ACPI_DUMMY) + dev_warn(&spi->dev, "do not use this driver in production systems!\n"); +} +#else +static inline void spidev_probe_acpi(struct spi_device *spi) {} +#endif + /*-------------------------------------------------------------------------*/ static int spidev_probe(struct spi_device *spi) @@ -719,6 +757,8 @@ static int spidev_probe(struct spi_device *spi) !of_match_device(spidev_dt_ids, &spi->dev)); } + spidev_probe_acpi(spi); + /* Allocate driver data */ spidev = kzalloc(sizeof(*spidev), GFP_KERNEL); if (!spidev) @@ -789,6 +829,7 @@ static struct spi_driver spidev_spi_driver = { .driver = { .name = "spidev", .of_match_table = of_match_ptr(spidev_dt_ids), + .acpi_match_table = ACPI_PTR(spidev_acpi_ids), }, .probe = spidev_probe, .remove = spidev_remove, From 0d35773979b9c0925edfefeaac173bbeafc83d94 Mon Sep 17 00:00:00 2001 From: Bhaktipriya Shridhar Date: Sun, 10 Jul 2016 19:42:13 +0530 Subject: [PATCH 6/6] spi: spi-topcliff-pch: Remove deprecated create_singlethread_workqueue The workqueue "wk" serves as a queue for carrying out execution of requests. It has a single work item(&drv_data->work) and hence doesn't require ordering. Also, it is not being used on a memory reclaim path. Hence, the singlethreaded workqueue has been replaced with the use of system_wq. System workqueues have been able to handle high level of concurrency for a long time now and hence it's not required to have a singlethreaded workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue created with create_singlethread_workqueue(), system_wq allows multiple work items to overlap executions even on the same CPU; however, a per-cpu workqueue doesn't have any CPU locality or global ordering guarantee unless the target CPU is explicitly specified and thus the increase of local concurrency shouldn't make any difference. Work item has been flushed in pch_spi_free_resources() to ensure that there are no pending tasks while disconnecting the driver. Also dropped the label 'err_return' since it's not being used anymore. Signed-off-by: Bhaktipriya Shridhar Signed-off-by: Mark Brown --- drivers/spi/spi-topcliff-pch.c | 26 +++----------------------- 1 file changed, 3 insertions(+), 23 deletions(-) diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c index 93dfcee0f987..c54ee6674471 100644 --- a/drivers/spi/spi-topcliff-pch.c +++ b/drivers/spi/spi-topcliff-pch.c @@ -133,8 +133,6 @@ struct pch_spi_dma_ctrl { * @io_remap_addr: The remapped PCI base address * @master: Pointer to the SPI master structure * @work: Reference to work queue handler - * @wk: Workqueue for carrying out execution of the - * requests * @wait: Wait queue for waking up upon receiving an * interrupt. * @transfer_complete: Status of SPI Transfer @@ -169,7 +167,6 @@ struct pch_spi_data { unsigned long io_base_addr; struct spi_master *master; struct work_struct work; - struct workqueue_struct *wk; wait_queue_head_t wait; u8 transfer_complete; u8 bcurrent_msg_processing; @@ -517,8 +514,7 @@ static int pch_spi_transfer(struct spi_device *pspi, struct spi_message *pmsg) dev_dbg(&pspi->dev, "%s - Invoked list_add_tail\n", __func__); - /* schedule work queue to run */ - queue_work(data->wk, &data->work); + schedule_work(&data->work); dev_dbg(&pspi->dev, "%s - Invoked queue work\n", __func__); retval = 0; @@ -674,7 +670,7 @@ static void pch_spi_nomore_transfer(struct pch_spi_data *data) *more messages) */ dev_dbg(&data->master->dev, "%s:Invoke queue_work\n", __func__); - queue_work(data->wk, &data->work); + schedule_work(&data->work); } else if (data->board_dat->suspend_sts || data->status == STATUS_EXITING) { dev_dbg(&data->master->dev, @@ -1266,14 +1262,7 @@ static void pch_spi_free_resources(struct pch_spi_board_data *board_dat, { dev_dbg(&board_dat->pdev->dev, "%s ENTRY\n", __func__); - /* free workqueue */ - if (data->wk != NULL) { - destroy_workqueue(data->wk); - data->wk = NULL; - dev_dbg(&board_dat->pdev->dev, - "%s destroy_workqueue invoked successfully\n", - __func__); - } + flush_work(&data->work); } static int pch_spi_get_resources(struct pch_spi_board_data *board_dat, @@ -1283,14 +1272,6 @@ static int pch_spi_get_resources(struct pch_spi_board_data *board_dat, dev_dbg(&board_dat->pdev->dev, "%s ENTRY\n", __func__); - /* create workqueue */ - data->wk = create_singlethread_workqueue(KBUILD_MODNAME); - if (!data->wk) { - dev_err(&board_dat->pdev->dev, - "%s create_singlet hread_workqueue failed\n", __func__); - retval = -EBUSY; - goto err_return; - } /* reset PCH SPI h/w */ pch_spi_reset(data->master); @@ -1299,7 +1280,6 @@ static int pch_spi_get_resources(struct pch_spi_board_data *board_dat, dev_dbg(&board_dat->pdev->dev, "%s data->irq_reg_sts=true\n", __func__); -err_return: if (retval != 0) { dev_err(&board_dat->pdev->dev, "%s FAIL:invoking pch_spi_free_resources\n", __func__);