From 42ce7fd6319bed8ecb26d656c476365da46b29e9 Mon Sep 17 00:00:00 2001 From: Gregory CLEMENT Date: Wed, 29 Dec 2010 11:52:53 +0100 Subject: spi/omap2_mcspi.c: Force CS to be in inactive state after off-mode transition When SPI wake up from OFF mode, CS is in the wrong state: force it to the inactive state. During the system life, I monitored the CS behavior using a oscilloscope. I also activated debug in omap2_mcspi, so I saw when driver disable the clocks and restore context when device is not used.Each time the CS was in the correct state. It was only when system was put suspend to ram with off-mode activated that on resume the CS was in wrong state( ie activated). Changelog: * Change from v1 to v2: - Rebase on linus/master (after 2.6.37-rc1) - Do some clean-up and fix indentation on both patches - Add more explanations for patch 2 * Change from v2 to v3: - Use directly resume function of spi_master instead of using function - from spi_device as Grant Likely pointed it out. - Force this transition explicitly for each CS used by a device. * Change from v3 to v4: - Patch clean-up according to Kevin Hilman and checkpatch. - Now force CS to be in inactive state only if it was inactive when it was suspended. * Change from v4 to v5: - Rebase on linus/master (after 2.6.37-rc3) - Collapse some lines as pointed by Grant Likely - Fix a spelling * Change from v5 to v6: - Rebase on linus/master (after 2.6.37-rc7) - Use CONFIG_SUSPEND instead of CONFIG_PM - Didn't use legacy PM methods anymore. Instead, add a struct dev_pm_ops and add the resume method there. - Fix multi-line comment style * Change from v6 to v7: - Rebase on linus/master (after 2.6.37-rc8) - Drop an extra line Signed-off-by: Gregory CLEMENT Acked-by: David Brownell Reviewed-by: Kevin Hilman Signed-off-by: Grant Likely --- drivers/spi/omap2_mcspi.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'drivers/spi/omap2_mcspi.c') diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c index 2a651e61bfbf..951a160fc27f 100644 --- a/drivers/spi/omap2_mcspi.c +++ b/drivers/spi/omap2_mcspi.c @@ -1305,10 +1305,49 @@ static int __exit omap2_mcspi_remove(struct platform_device *pdev) /* work with hotplug and coldplug */ MODULE_ALIAS("platform:omap2_mcspi"); +#ifdef CONFIG_SUSPEND +/* + * When SPI wake up from off-mode, CS is in activate state. If it was in + * unactive state when driver was suspend, then force it to unactive state at + * wake up. + */ +static int omap2_mcspi_resume(struct device *dev) +{ + struct spi_master *master = dev_get_drvdata(dev); + struct omap2_mcspi *mcspi = spi_master_get_devdata(master); + struct omap2_mcspi_cs *cs; + + omap2_mcspi_enable_clocks(mcspi); + list_for_each_entry(cs, &omap2_mcspi_ctx[master->bus_num - 1].cs, + node) { + if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) { + + /* + * We need to toggle CS state for OMAP take this + * change in account. + */ + MOD_REG_BIT(cs->chconf0, OMAP2_MCSPI_CHCONF_FORCE, 1); + __raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0); + MOD_REG_BIT(cs->chconf0, OMAP2_MCSPI_CHCONF_FORCE, 0); + __raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0); + } + } + omap2_mcspi_disable_clocks(mcspi); + return 0; +} +#else +#define omap2_mcspi_resume NULL +#endif + +static const struct dev_pm_ops omap2_mcspi_pm_ops = { + .resume = omap2_mcspi_resume, +}; + static struct platform_driver omap2_mcspi_driver = { .driver = { .name = "omap2_mcspi", .owner = THIS_MODULE, + .pm = &omap2_mcspi_pm_ops }, .remove = __exit_p(omap2_mcspi_remove), }; -- cgit From 07fe0351702b6f0c9749e80cdbcb758686b0fe9b Mon Sep 17 00:00:00 2001 From: Russell King - ARM Linux Date: Fri, 7 Jan 2011 15:49:20 +0000 Subject: spi/omap: Fix DMA API usage in OMAP MCSPI driver Running the latest kernel on the 4430SDP board with DMA API debugging enabled results in this: WARNING: at lib/dma-debug.c:803 check_unmap+0x19c/0x6f0() NULL NULL: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x000000008129901a] [size=260 bytes] Modules linked in: Backtrace: [] (dump_backtrace+0x0/0x10c) from [] (dump_stack+0x18/0x1c) r7:c1839dc0 r6:c0198578 r5:c0304b17 r4:00000323 [] (dump_stack+0x0/0x1c) from [] (warn_slowpath_common+0x58/0x70) [] (warn_slowpath_common+0x0/0x70) from [] (warn_slowpath_fmt+0x38/0x40) r8:c1839e40 r7:00000000 r6:00000104 r5:00000000 r4:8129901a [] (warn_slowpath_fmt+0x0/0x40) from [] (check_unmap+0x19c/0x6f0) r3:c03110de r2:c0304e6b [] (check_unmap+0x0/0x6f0) from [] (debug_dma_unmap_page+0x74/0x80) [] (debug_dma_unmap_page+0x0/0x80) from [] (omap2_mcspi_work+0x514/0xbf0) [] (omap2_mcspi_work+0x0/0xbf0) from [] (process_one_work+0x294/0x400) [] (process_one_work+0x0/0x400) from [] (worker_thread+0x220/0x3f8) [] (worker_thread+0x0/0x3f8) from [] (kthread+0x88/0x90) [] (kthread+0x0/0x90) from [] (do_exit+0x0/0x5fc) r7:00000013 r6:c005e924 r5:c0073848 r4:c1829ee0 ---[ end trace 1b75b31a2719ed20 ]--- I've no idea why this driver uses NULL for dma_unmap_single instead of the &spi->dev that is laying around just waiting to be used in that function - but it's an easy fix. Also replace this comment with a FIXME comment: /* Do DMA mapping "early" for better error reporting and * dcache use. Note that if dma_unmap_single() ever starts * to do real work on ARM, we'd need to clean up mappings * for previous transfers on *ALL* exits of this loop... */ as the comment is not true - we do work in dma_unmap() functions, particularly on ARMv6 and above. I've corrected the existing unmap functions but if any others are required they must be added ASAP. Signed-off-by: Russell King Acked-by: Tony Lindgren Signed-off-by: Grant Likely --- drivers/spi/omap2_mcspi.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) (limited to 'drivers/spi/omap2_mcspi.c') diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c index 2a651e61bfbf..df85990bb335 100644 --- a/drivers/spi/omap2_mcspi.c +++ b/drivers/spi/omap2_mcspi.c @@ -397,7 +397,7 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) if (tx != NULL) { wait_for_completion(&mcspi_dma->dma_tx_completion); - dma_unmap_single(NULL, xfer->tx_dma, count, DMA_TO_DEVICE); + dma_unmap_single(&spi->dev, xfer->tx_dma, count, DMA_TO_DEVICE); /* for TX_ONLY mode, be sure all words have shifted out */ if (rx == NULL) { @@ -412,7 +412,7 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) if (rx != NULL) { wait_for_completion(&mcspi_dma->dma_rx_completion); - dma_unmap_single(NULL, xfer->rx_dma, count, DMA_FROM_DEVICE); + dma_unmap_single(&spi->dev, xfer->rx_dma, count, DMA_FROM_DEVICE); omap2_mcspi_set_enable(spi, 0); if (l & OMAP2_MCSPI_CHCONF_TURBO) { @@ -1025,11 +1025,6 @@ static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m) if (m->is_dma_mapped || len < DMA_MIN_BYTES) continue; - /* Do DMA mapping "early" for better error reporting and - * dcache use. Note that if dma_unmap_single() ever starts - * to do real work on ARM, we'd need to clean up mappings - * for previous transfers on *ALL* exits of this loop... - */ if (tx_buf != NULL) { t->tx_dma = dma_map_single(&spi->dev, (void *) tx_buf, len, DMA_TO_DEVICE); @@ -1046,7 +1041,7 @@ static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m) dev_dbg(&spi->dev, "dma %cX %d bytes error\n", 'R', len); if (tx_buf != NULL) - dma_unmap_single(NULL, t->tx_dma, + dma_unmap_single(&spi->dev, t->tx_dma, len, DMA_TO_DEVICE); return -EINVAL; } -- cgit