From ce1dac560a74220f2e53845ec0723b562288aed4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Wed, 8 May 2024 11:56:10 +0200 Subject: [PATCH 1/7] spi: imx: Don't expect DMA for i.MX{25,35,50,51,53} cspi devices MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit While in commit 2dd33f9cec90 ("spi: imx: support DMA for imx35") it was claimed that DMA works on i.MX25, i.MX31 and i.MX35 the respective device trees don't add DMA channels. The Reference manuals of i.MX31 and i.MX25 also don't mention the CSPI core being DMA capable. (I didn't check the others.) Since commit e267a5b3ec59 ("spi: spi-imx: Use dev_err_probe for failed DMA channel requests") this results in an error message spi_imx 43fa4000.spi: error -ENODEV: can't get the TX DMA channel! during boot. However that isn't fatal and the driver gets loaded just fine, just without using DMA. Signed-off-by: Uwe Kleine-König Link: https://patch.msgid.link/20240508095610.2146640-2-u.kleine-koenig@pengutronix.de Signed-off-by: Mark Brown --- drivers/spi/spi-imx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 33164ebdb583..1439883326cf 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -1050,7 +1050,7 @@ static struct spi_imx_devtype_data imx35_cspi_devtype_data = { .rx_available = mx31_rx_available, .reset = mx31_reset, .fifo_size = 8, - .has_dmamode = true, + .has_dmamode = false, .dynamic_burst = false, .has_targetmode = false, .devtype = IMX35_CSPI, From 40b3d0838a1ff242e61f341e49226074bbdd319f Mon Sep 17 00:00:00 2001 From: David Lechner Date: Thu, 20 Jun 2024 11:43:58 -0500 Subject: [PATCH 2/7] spi: axi-spi-engine: fix sleep calculation The sleep calculation was not taking into account increased delay when the SPI device is not running at the maximum SCLK frequency. Rounding down when one SCLK tick was the same as the instruction execution time was fine, but it rounds down too much when SCLK is slower. This changes the rounding to round up instead while still taking into account the instruction execution time so that small delays remain accurate. Fixes: be9070bcf670 ("spi: axi-spi-engine: fix sleep ticks calculation") Signed-off-by: David Lechner Link: https://patch.msgid.link/20240620-spi-axi-spi-engine-fix-sleep-time-v1-1-b20b527924a0@baylibre.com Signed-off-by: Mark Brown --- drivers/spi/spi-axi-spi-engine.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/drivers/spi/spi-axi-spi-engine.c b/drivers/spi/spi-axi-spi-engine.c index e358ac5b4509..96a524772549 100644 --- a/drivers/spi/spi-axi-spi-engine.c +++ b/drivers/spi/spi-axi-spi-engine.c @@ -164,16 +164,20 @@ static void spi_engine_gen_xfer(struct spi_engine_program *p, bool dry, } static void spi_engine_gen_sleep(struct spi_engine_program *p, bool dry, - int delay_ns, u32 sclk_hz) + int delay_ns, int inst_ns, u32 sclk_hz) { unsigned int t; - /* negative delay indicates error, e.g. from spi_delay_to_ns() */ - if (delay_ns <= 0) + /* + * Negative delay indicates error, e.g. from spi_delay_to_ns(). And if + * delay is less that the instruction execution time, there is no need + * for an extra sleep instruction since the instruction execution time + * will already cover the required delay. + */ + if (delay_ns < 0 || delay_ns <= inst_ns) return; - /* rounding down since executing the instruction adds a couple of ticks delay */ - t = DIV_ROUND_DOWN_ULL((u64)delay_ns * sclk_hz, NSEC_PER_SEC); + t = DIV_ROUND_UP_ULL((u64)(delay_ns - inst_ns) * sclk_hz, NSEC_PER_SEC); while (t) { unsigned int n = min(t, 256U); @@ -220,10 +224,16 @@ static void spi_engine_compile_message(struct spi_message *msg, bool dry, struct spi_device *spi = msg->spi; struct spi_controller *host = spi->controller; struct spi_transfer *xfer; - int clk_div, new_clk_div; + int clk_div, new_clk_div, inst_ns; bool keep_cs = false; u8 bits_per_word = 0; + /* + * Take into account instruction execution time for more accurate sleep + * times, especially when the delay is small. + */ + inst_ns = DIV_ROUND_UP(NSEC_PER_SEC, host->max_speed_hz); + clk_div = 1; spi_engine_program_add_cmd(p, dry, @@ -252,7 +262,7 @@ static void spi_engine_compile_message(struct spi_message *msg, bool dry, spi_engine_gen_xfer(p, dry, xfer); spi_engine_gen_sleep(p, dry, spi_delay_to_ns(&xfer->delay, xfer), - xfer->effective_speed_hz); + inst_ns, xfer->effective_speed_hz); if (xfer->cs_change) { if (list_is_last(&xfer->transfer_list, &msg->transfers)) { @@ -262,7 +272,7 @@ static void spi_engine_compile_message(struct spi_message *msg, bool dry, spi_engine_gen_cs(p, dry, spi, false); spi_engine_gen_sleep(p, dry, spi_delay_to_ns( - &xfer->cs_change_delay, xfer), + &xfer->cs_change_delay, xfer), inst_ns, xfer->effective_speed_hz); if (!list_next_entry(xfer, transfer_list)->cs_off) From 1762dc01fc78ef5f19693e9317eae7491c6c7e1b Mon Sep 17 00:00:00 2001 From: Bastien Curutchet Date: Mon, 24 Jun 2024 09:17:45 +0200 Subject: [PATCH 3/7] spi: davinci: Unset POWERDOWN bit when releasing resources On the OMAPL138, the SPI reference clock is provided by the Power and Sleep Controller (PSC). The PSC's datasheet says that 'some peripherals have special programming requirements and additional recommended steps you must take before you can invoke the PSC module state transition'. I didn't find more details in documentation but it appears that PSC needs the SPI to clear the POWERDOWN bit before disabling the clock. Indeed, when this bit is set, the PSC gets stuck in transitions from enable to disable state. Clear the POWERDOWN bit when releasing driver's resources Signed-off-by: Bastien Curutchet Link: https://patch.msgid.link/20240624071745.17409-1-bastien.curutchet@bootlin.com Signed-off-by: Mark Brown --- drivers/spi/spi-davinci.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c index be3998104bfb..f7e8b5efa50e 100644 --- a/drivers/spi/spi-davinci.c +++ b/drivers/spi/spi-davinci.c @@ -984,6 +984,9 @@ static int davinci_spi_probe(struct platform_device *pdev) return ret; free_dma: + /* This bit needs to be cleared to disable dpsi->clk */ + clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK); + if (dspi->dma_rx) { dma_release_channel(dspi->dma_rx); dma_release_channel(dspi->dma_tx); @@ -1013,6 +1016,9 @@ static void davinci_spi_remove(struct platform_device *pdev) spi_bitbang_stop(&dspi->bitbang); + /* This bit needs to be cleared to disable dpsi->clk */ + clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK); + if (dspi->dma_rx) { dma_release_channel(dspi->dma_rx); dma_release_channel(dspi->dma_tx); From 8221545c440b5f83f00b3e5a92bbc86bf268bad4 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Thu, 4 Jul 2024 13:05:48 +0100 Subject: [PATCH 4/7] spi: omap2-mcspi: Revert multi mode support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit There have been multiple reports that the multi-mode support in the OMAP2 McSPI driver has caused regressions on existing systems. There's been some discussion and some proposed changes but nothing that's been tested by all the reporters. Drop the patch for v6.10, hopefully we can get to the bottom of the issue and reenable the feature for v6.11. Reported-by: Colin Foster Reported-by: João Paulo Gonçalves Fixes: e64d3b6fc9a3 ("spi: omap2-mcpsi: Enable MULTI-mode in more situations") Signed-off-by: Mark Brown Link: https://patch.msgid.link/20240704-spi-revert-omap2-multi-v1-1-69357ef13fdc@kernel.org Signed-off-by: Mark Brown --- drivers/spi/spi-omap2-mcspi.c | 15 +-------------- 1 file changed, 1 insertion(+), 14 deletions(-) diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index 7e3083b83534..002f29dbcea6 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -1277,24 +1277,11 @@ static int omap2_mcspi_prepare_message(struct spi_controller *ctlr, /* * Check if this transfer contains only one word; - * OR contains 1 to 4 words, with bits_per_word == 8 and no delay between each word - * OR contains 1 to 2 words, with bits_per_word == 16 and no delay between each word - * - * If one of the two last case is true, this also change the bits_per_word of this - * transfer to make it a bit faster. - * It's not an issue to change the bits_per_word here even if the multi-mode is not - * applicable for this message, the signal on the wire will be the same. */ if (bits_per_word < 8 && tr->len == 1) { /* multi-mode is applicable, only one word (1..7 bits) */ - } else if (tr->word_delay.value == 0 && bits_per_word == 8 && tr->len <= 4) { - /* multi-mode is applicable, only one "bigger" word (8,16,24,32 bits) */ - tr->bits_per_word = tr->len * bits_per_word; - } else if (tr->word_delay.value == 0 && bits_per_word == 16 && tr->len <= 2) { - /* multi-mode is applicable, only one "bigger" word (16,32 bits) */ - tr->bits_per_word = tr->len * bits_per_word / 2; } else if (bits_per_word >= 8 && tr->len == bits_per_word / 8) { - /* multi-mode is applicable, only one word (9..15,17..32 bits) */ + /* multi-mode is applicable, only one word (8..32 bits) */ } else { /* multi-mode is not applicable: more than one word in the transfer */ mcspi->use_multi_mode = false; From c86a918b1bdba78fb155184f8d88dfba1e63335d Mon Sep 17 00:00:00 2001 From: David Lechner Date: Mon, 8 Jul 2024 20:05:28 -0500 Subject: [PATCH 5/7] spi: don't unoptimize message in spi_async() Calling spi_maybe_unoptimize_message() in spi_async() is wrong because the message is likely to be in the queue and not transferred yet. This can corrupt the message while it is being used by the controller driver. spi_maybe_unoptimize_message() is already called in the correct place in spi_finalize_current_message() to balance the call to spi_maybe_optimize_message() in spi_async(). Fixes: 7b1d87af14d9 ("spi: add spi_optimize_message() APIs") Signed-off-by: David Lechner Link: https://patch.msgid.link/20240708-spi-mux-fix-v1-1-6c8845193128@baylibre.com Signed-off-by: Mark Brown --- drivers/spi/spi.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index fc13fa192189..679ee414cbea 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -4432,8 +4432,6 @@ int spi_async(struct spi_device *spi, struct spi_message *message) spin_unlock_irqrestore(&ctlr->bus_lock_spinlock, flags); - spi_maybe_unoptimize_message(message); - return ret; } EXPORT_SYMBOL_GPL(spi_async); From ca52aa4c60f76566601b42e935b8a78f0fb4f8eb Mon Sep 17 00:00:00 2001 From: David Lechner Date: Mon, 8 Jul 2024 20:05:29 -0500 Subject: [PATCH 6/7] spi: add defer_optimize_message controller flag Adding spi_optimize_message() broke the spi-mux driver because it calls spi_async() from it's transfer_one_message() callback. This resulted in passing an incorrectly optimized message to the controller. For example, if the underlying controller has an optimize_message() callback, this would have not been called and can cause a crash when the underlying controller driver tries to transfer the message. Also, since the spi-mux driver swaps out the controller pointer by replacing msg->spi, __spi_unoptimize_message() was being called with a different controller than the one used in __spi_optimize_message(). This could cause a crash when attempting to free the message resources when __spi_unoptimize_message() is called in spi_finalize_current_message() since it is being called with a controller that did not allocate the resources. This is fixed by adding a defer_optimize_message flag for controllers. This flag causes all of the spi_[maybe_][un]optimize_message() calls to be a no-op (other than attaching a pointer to the spi device to the message). This allows the spi-mux driver to pass an unmodified message to spi_async() in spi_mux_transfer_one_message() after the spi device has been swapped out. This causes __spi_optimize_message() and __spi_unoptimize_message() to be called only once per message and with the correct/same controller in each case. Reported-by: Oleksij Rempel Closes: https://lore.kernel.org/linux-spi/Zn6HMrYG2b7epUxT@pengutronix.de/ Reported-by: Marc Kleine-Budde Closes: https://lore.kernel.org/linux-spi/20240628-awesome-discerning-bear-1621f9-mkl@pengutronix.de/ Fixes: 7b1d87af14d9 ("spi: add spi_optimize_message() APIs") Signed-off-by: David Lechner Link: https://patch.msgid.link/20240708-spi-mux-fix-v1-2-6c8845193128@baylibre.com Signed-off-by: Mark Brown --- drivers/spi/spi-mux.c | 1 + drivers/spi/spi.c | 18 +++++++++++++++++- include/linux/spi/spi.h | 4 ++++ 3 files changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-mux.c b/drivers/spi/spi-mux.c index 5d72e3d59df8..f4b619cc2657 100644 --- a/drivers/spi/spi-mux.c +++ b/drivers/spi/spi-mux.c @@ -164,6 +164,7 @@ static int spi_mux_probe(struct spi_device *spi) ctlr->bus_num = -1; ctlr->dev.of_node = spi->dev.of_node; ctlr->must_async = true; + ctlr->defer_optimize_message = true; ret = devm_spi_register_controller(&spi->dev, ctlr); if (ret) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 679ee414cbea..0f04e832f9ec 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2151,7 +2151,8 @@ static void __spi_unoptimize_message(struct spi_message *msg) */ static void spi_maybe_unoptimize_message(struct spi_message *msg) { - if (!msg->pre_optimized && msg->optimized) + if (!msg->pre_optimized && msg->optimized && + !msg->spi->controller->defer_optimize_message) __spi_unoptimize_message(msg); } @@ -4294,6 +4295,11 @@ static int __spi_optimize_message(struct spi_device *spi, static int spi_maybe_optimize_message(struct spi_device *spi, struct spi_message *msg) { + if (spi->controller->defer_optimize_message) { + msg->spi = spi; + return 0; + } + if (msg->pre_optimized) return 0; @@ -4324,6 +4330,13 @@ int spi_optimize_message(struct spi_device *spi, struct spi_message *msg) { int ret; + /* + * Pre-optimization is not supported and optimization is deferred e.g. + * when using spi-mux. + */ + if (spi->controller->defer_optimize_message) + return 0; + ret = __spi_optimize_message(spi, msg); if (ret) return ret; @@ -4350,6 +4363,9 @@ EXPORT_SYMBOL_GPL(spi_optimize_message); */ void spi_unoptimize_message(struct spi_message *msg) { + if (msg->spi->controller->defer_optimize_message) + return; + __spi_unoptimize_message(msg); msg->pre_optimized = false; } diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 98fdef6e28f2..67b9a15a5330 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -533,6 +533,9 @@ extern struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 ch * @queue_empty: signal green light for opportunistically skipping the queue * for spi_sync transfers. * @must_async: disable all fast paths in the core + * @defer_optimize_message: set to true if controller cannot pre-optimize messages + * and needs to defer the optimization step until the message is actually + * being transferred * * Each SPI controller can communicate with one or more @spi_device * children. These make a small bus, sharing MOSI, MISO and SCK signals @@ -776,6 +779,7 @@ struct spi_controller { /* Flag for enabling opportunistic skipping of the queue in spi_sync */ bool queue_empty; bool must_async; + bool defer_optimize_message; }; static inline void *spi_controller_get_devdata(struct spi_controller *ctlr) From c8bd922d924bb4ab6c6c488310157d1a27996f31 Mon Sep 17 00:00:00 2001 From: David Lechner Date: Mon, 8 Jul 2024 20:05:30 -0500 Subject: [PATCH 7/7] spi: mux: set ctlr->bits_per_word_mask Like other SPI controller flags, bits_per_word_mask may be used by a peripheral driver, so it needs to reflect the capabilities of the underlying controller. Signed-off-by: David Lechner Link: https://patch.msgid.link/20240708-spi-mux-fix-v1-3-6c8845193128@baylibre.com Signed-off-by: Mark Brown --- drivers/spi/spi-mux.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/spi/spi-mux.c b/drivers/spi/spi-mux.c index f4b619cc2657..c02c4204442f 100644 --- a/drivers/spi/spi-mux.c +++ b/drivers/spi/spi-mux.c @@ -158,6 +158,7 @@ static int spi_mux_probe(struct spi_device *spi) /* supported modes are the same as our parent's */ ctlr->mode_bits = spi->controller->mode_bits; ctlr->flags = spi->controller->flags; + ctlr->bits_per_word_mask = spi->controller->bits_per_word_mask; ctlr->transfer_one_message = spi_mux_transfer_one_message; ctlr->setup = spi_mux_setup; ctlr->num_chipselect = mux_control_states(priv->mux);