From 45b064d73d6a5cfcfa76012b91e2afc98e341664 Mon Sep 17 00:00:00 2001 From: Alexander Sverdlin Date: Fri, 27 Feb 2015 16:30:01 +0100 Subject: spi: pl022: Remove incorrect TxFIFO full reporting According to PL022 specification, TNF bit states for "Transmit FIFO Not full". So the logic here is inverted. But "Receive Overrun Interrupt", which is handled here, is only triggered on Rx errors. So instead of fixing the if statement, remove the whole message. Signed-off-by: Alexander Sverdlin Signed-off-by: Mark Brown --- drivers/spi/spi-pl022.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'drivers') diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c index 89ca162801da..4381fcf2389c 100644 --- a/drivers/spi/spi-pl022.c +++ b/drivers/spi/spi-pl022.c @@ -1280,9 +1280,6 @@ static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id) if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF) dev_err(&pl022->adev->dev, "RXFIFO is full\n"); - if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_TNF) - dev_err(&pl022->adev->dev, - "TXFIFO is full\n"); /* * Disable and clear interrupts, disable SSP, -- cgit v1.2.3 From 85fa4e1f094183d230c47fa1e83373f692dc05ec Mon Sep 17 00:00:00 2001 From: Alexander Sverdlin Date: Fri, 27 Feb 2015 16:30:07 +0100 Subject: spi: pl022: Don't touch unspecified bits in interrupt mask PL022 Programmers model explicitely states "do not modify undefined register bits". Correct the "all enable" interrupt mask so that it only enables defined ones. Signed-off-by: Alexander Sverdlin Signed-off-by: Mark Brown --- drivers/spi/spi-pl022.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c index 4381fcf2389c..a45406aa2b14 100644 --- a/drivers/spi/spi-pl022.c +++ b/drivers/spi/spi-pl022.c @@ -285,7 +285,12 @@ */ #define DEFAULT_SSP_REG_IMSC 0x0UL #define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC -#define ENABLE_ALL_INTERRUPTS (~DEFAULT_SSP_REG_IMSC) +#define ENABLE_ALL_INTERRUPTS ( \ + SSP_IMSC_MASK_RORIM | \ + SSP_IMSC_MASK_RTIM | \ + SSP_IMSC_MASK_RXIM | \ + SSP_IMSC_MASK_TXIM \ +) #define CLEAR_ALL_INTERRUPTS 0x3 -- cgit v1.2.3 From 7183d1ebda477c48e5f51f854a766c96b6c0e142 Mon Sep 17 00:00:00 2001 From: Alexander Sverdlin Date: Fri, 27 Feb 2015 16:30:15 +0100 Subject: spi: pl022: Remove dead code "flag" variable does nothing, remove it. Signed-off-by: Alexander Sverdlin Signed-off-by: Mark Brown --- drivers/spi/spi-pl022.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'drivers') diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c index a45406aa2b14..e96189c7834c 100644 --- a/drivers/spi/spi-pl022.c +++ b/drivers/spi/spi-pl022.c @@ -1256,7 +1256,6 @@ static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id) struct pl022 *pl022 = dev_id; struct spi_message *msg = pl022->cur_msg; u16 irq_status = 0; - u16 flag = 0; if (unlikely(!msg)) { dev_err(&pl022->adev->dev, @@ -1305,8 +1304,7 @@ static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id) readwriter(pl022); - if ((pl022->tx == pl022->tx_end) && (flag == 0)) { - flag = 1; + if (pl022->tx == pl022->tx_end) { /* Disable Transmit interrupt, enable receive interrupt */ writew((readw(SSP_IMSC(pl022->virtbase)) & ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM, -- cgit v1.2.3 From ea022bbb0090975a21c581d8405fbe90043a6eda Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Sun, 8 Mar 2015 14:56:38 +0100 Subject: spi: Remove support for legacy PM All SPI drivers have been converted from legacy suspend/resume callbacks to dev_pm_ops. So we can finally remove support for legacy PM from the SPI core. Since there aren't any special bus specific things to do during suspend/resume and since the PM core will automatically fallback directly to using the device's PM ops if no bus PM ops are specified there is no need to have any special SPI bus PM ops. Signed-off-by: Lars-Peter Clausen Signed-off-by: Mark Brown --- drivers/spi/spi.c | 114 ------------------------------------------------ include/linux/spi/spi.h | 4 -- 2 files changed, 118 deletions(-) (limited to 'drivers') diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index c64a3e59fce3..7a2b7a7cb650 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -129,125 +129,11 @@ static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) return 0; } -#ifdef CONFIG_PM_SLEEP -static int spi_legacy_suspend(struct device *dev, pm_message_t message) -{ - int value = 0; - struct spi_driver *drv = to_spi_driver(dev->driver); - - /* suspend will stop irqs and dma; no more i/o */ - if (drv) { - if (drv->suspend) - value = drv->suspend(to_spi_device(dev), message); - else - dev_dbg(dev, "... can't suspend\n"); - } - return value; -} - -static int spi_legacy_resume(struct device *dev) -{ - int value = 0; - struct spi_driver *drv = to_spi_driver(dev->driver); - - /* resume may restart the i/o queue */ - if (drv) { - if (drv->resume) - value = drv->resume(to_spi_device(dev)); - else - dev_dbg(dev, "... can't resume\n"); - } - return value; -} - -static int spi_pm_suspend(struct device *dev) -{ - const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; - - if (pm) - return pm_generic_suspend(dev); - else - return spi_legacy_suspend(dev, PMSG_SUSPEND); -} - -static int spi_pm_resume(struct device *dev) -{ - const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; - - if (pm) - return pm_generic_resume(dev); - else - return spi_legacy_resume(dev); -} - -static int spi_pm_freeze(struct device *dev) -{ - const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; - - if (pm) - return pm_generic_freeze(dev); - else - return spi_legacy_suspend(dev, PMSG_FREEZE); -} - -static int spi_pm_thaw(struct device *dev) -{ - const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; - - if (pm) - return pm_generic_thaw(dev); - else - return spi_legacy_resume(dev); -} - -static int spi_pm_poweroff(struct device *dev) -{ - const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; - - if (pm) - return pm_generic_poweroff(dev); - else - return spi_legacy_suspend(dev, PMSG_HIBERNATE); -} - -static int spi_pm_restore(struct device *dev) -{ - const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; - - if (pm) - return pm_generic_restore(dev); - else - return spi_legacy_resume(dev); -} -#else -#define spi_pm_suspend NULL -#define spi_pm_resume NULL -#define spi_pm_freeze NULL -#define spi_pm_thaw NULL -#define spi_pm_poweroff NULL -#define spi_pm_restore NULL -#endif - -static const struct dev_pm_ops spi_pm = { - .suspend = spi_pm_suspend, - .resume = spi_pm_resume, - .freeze = spi_pm_freeze, - .thaw = spi_pm_thaw, - .poweroff = spi_pm_poweroff, - .restore = spi_pm_restore, - SET_RUNTIME_PM_OPS( - pm_generic_runtime_suspend, - pm_generic_runtime_resume, - NULL - ) -}; - struct bus_type spi_bus_type = { .name = "spi", .dev_groups = spi_dev_groups, .match = spi_match_device, .uevent = spi_uevent, - .pm = &spi_pm, }; EXPORT_SYMBOL_GPL(spi_bus_type); diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index ed9489d893a4..9f6b481e8672 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -162,8 +162,6 @@ struct spi_transfer; * @remove: Unbinds this driver from the spi device * @shutdown: Standard shutdown callback used during system state * transitions such as powerdown/halt and kexec - * @suspend: Standard suspend callback used during system state transitions - * @resume: Standard resume callback used during system state transitions * @driver: SPI device drivers should initialize the name and owner * field of this structure. * @@ -184,8 +182,6 @@ struct spi_driver { int (*probe)(struct spi_device *spi); int (*remove)(struct spi_device *spi); void (*shutdown)(struct spi_device *spi); - int (*suspend)(struct spi_device *spi, pm_message_t mesg); - int (*resume)(struct spi_device *spi); struct device_driver driver; }; -- cgit v1.2.3 From db91841b58f9ad0ecbb81ed0fa496c3a1b67fd63 Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Wed, 10 Dec 2014 18:16:25 +0000 Subject: spi/omap100k: Convert to runtime PM Currently the omap100k driver uses prepare and unprepare transfer hardware to enable and disable clocks for the IP block. Since these functions are called along with runtime PM and end up duplicating its functionality in a less flexible fashion we are trying to phase them out so convert this driver to do runtime PM instead. While doing so add missing error handling and remove a redundant NULL assignment. Signed-off-by: Mark Brown --- drivers/spi/spi-omap-100k.c | 101 +++++++++++++++++++++++++++++++++----------- 1 file changed, 77 insertions(+), 24 deletions(-) (limited to 'drivers') diff --git a/drivers/spi/spi-omap-100k.c b/drivers/spi/spi-omap-100k.c index d890d309dff9..35b332dacb13 100644 --- a/drivers/spi/spi-omap-100k.c +++ b/drivers/spi/spi-omap-100k.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include #include @@ -294,16 +295,6 @@ static int omap1_spi100k_setup(struct spi_device *spi) return ret; } -static int omap1_spi100k_prepare_hardware(struct spi_master *master) -{ - struct omap1_spi100k *spi100k = spi_master_get_devdata(master); - - clk_prepare_enable(spi100k->ick); - clk_prepare_enable(spi100k->fck); - - return 0; -} - static int omap1_spi100k_transfer_one_message(struct spi_master *master, struct spi_message *m) { @@ -372,16 +363,6 @@ static int omap1_spi100k_transfer_one_message(struct spi_master *master, return status; } -static int omap1_spi100k_unprepare_hardware(struct spi_master *master) -{ - struct omap1_spi100k *spi100k = spi_master_get_devdata(master); - - clk_disable_unprepare(spi100k->ick); - clk_disable_unprepare(spi100k->fck); - - return 0; -} - static int omap1_spi100k_probe(struct platform_device *pdev) { struct spi_master *master; @@ -402,14 +383,12 @@ static int omap1_spi100k_probe(struct platform_device *pdev) master->setup = omap1_spi100k_setup; master->transfer_one_message = omap1_spi100k_transfer_one_message; - master->prepare_transfer_hardware = omap1_spi100k_prepare_hardware; - master->unprepare_transfer_hardware = omap1_spi100k_unprepare_hardware; - master->cleanup = NULL; master->num_chipselect = 2; master->mode_bits = MODEBITS; master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32); master->min_speed_hz = OMAP1_SPI100K_MAX_FREQ/(1<<16); master->max_speed_hz = OMAP1_SPI100K_MAX_FREQ; + master->auto_runtime_pm = true; spi100k = spi_master_get_devdata(master); @@ -434,22 +413,96 @@ static int omap1_spi100k_probe(struct platform_device *pdev) goto err; } + status = clk_prepare_enable(spi100k->ick); + if (status != 0) { + dev_err(&pdev->dev, "failed to enable ick: %d\n", status); + goto err; + } + + status = clk_prepare_enable(spi100k->fck); + if (status != 0) { + dev_err(&pdev->dev, "failed to enable fck: %d\n", status); + goto err_ick; + } + + pm_runtime_enable(&pdev->dev); + pm_runtime_set_active(&pdev->dev); + status = devm_spi_register_master(&pdev->dev, master); if (status < 0) - goto err; + goto err_fck; return status; +err_fck: + clk_disable_unprepare(spi100k->fck); +err_ick: + clk_disable_unprepare(spi100k->ick); err: spi_master_put(master); return status; } +static int omap1_spi100k_remove(struct platform_device *pdev) +{ + struct spi_master *master = spi_master_get(platform_get_drvdata(pdev)); + struct omap1_spi100k *spi100k = spi_master_get_devdata(master); + + pm_runtime_disable(&pdev->dev); + + clk_disable_unprepare(spi100k->fck); + clk_disable_unprepare(spi100k->ick); + + return 0; +} + +#ifdef CONFIG_PM +static int omap1_spi100k_runtime_suspend(struct device *dev) +{ + struct spi_master *master = spi_master_get(dev_get_drvdata(dev)); + struct omap1_spi100k *spi100k = spi_master_get_devdata(master); + + clk_disable_unprepare(spi100k->ick); + clk_disable_unprepare(spi100k->fck); + + return 0; +} + +static int omap1_spi100k_runtime_resume(struct device *dev) +{ + struct spi_master *master = spi_master_get(dev_get_drvdata(dev)); + struct omap1_spi100k *spi100k = spi_master_get_devdata(master); + int ret; + + ret = clk_prepare_enable(spi100k->ick); + if (ret != 0) { + dev_err(dev, "Failed to enable ick: %d\n", ret); + return ret; + } + + ret = clk_prepare_enable(spi100k->fck); + if (ret != 0) { + dev_err(dev, "Failed to enable fck: %d\n", ret); + clk_disable_unprepare(spi100k->ick); + return ret; + } + + return 0; +} +#endif + +static const struct dev_pm_ops omap1_spi100k_pm = { + SET_RUNTIME_PM_OPS(omap1_spi100k_runtime_suspend, + omap1_spi100k_runtime_resume, NULL) +}; + static struct platform_driver omap1_spi100k_driver = { .driver = { .name = "omap1_spi100k", + .pm = &omap1_spi100k_pm, }, .probe = omap1_spi100k_probe, + .remove = omap1_spi100k_remove, }; module_platform_driver(omap1_spi100k_driver); -- cgit v1.2.3 From 22d1b94d4b04878a6d1514a21af04699bd27e0ce Mon Sep 17 00:00:00 2001 From: Jarkko Nikula Date: Mon, 23 Mar 2015 14:07:47 +0200 Subject: spi: pxa2xx: Remove needless includes These asm/io.h, asm/irq.h and asm/delay.h are needless since they are already included by linux/io.h via drivers/spi/spi-pxa2xx.h, linux/interrupt.h and linux/delay.h. Signed-off-by: Jarkko Nikula Signed-off-by: Mark Brown --- drivers/spi/spi-pxa2xx.c | 4 ---- 1 file changed, 4 deletions(-) (limited to 'drivers') diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index 6f72ad01e041..74342d167324 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -30,10 +30,6 @@ #include #include -#include -#include -#include - #include "spi-pxa2xx.h" MODULE_AUTHOR("Stephen Street"); -- cgit v1.2.3 From d4f9dcd1ac94e61e097951fd3dfb1cdf000a2660 Mon Sep 17 00:00:00 2001 From: Jarkko Nikula Date: Mon, 23 Mar 2015 14:07:48 +0200 Subject: spi: omap-uwire: Remove needless include asm/irq.h asm/irq.h is already included by linux/interrupt.h. Signed-off-by: Jarkko Nikula Signed-off-by: Mark Brown --- drivers/spi/spi-omap-uwire.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers') diff --git a/drivers/spi/spi-omap-uwire.c b/drivers/spi/spi-omap-uwire.c index 3c0844457c07..55576db31549 100644 --- a/drivers/spi/spi-omap-uwire.c +++ b/drivers/spi/spi-omap-uwire.c @@ -44,7 +44,6 @@ #include #include -#include #include #include -- cgit v1.2.3 From 025ffe88ee605acb03dba0d920908dff5ec15dd0 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Tue, 24 Mar 2015 17:43:21 +0200 Subject: spi: pxa2xx: shift clk_div in one place This patch refactors ssp_get_clk_div() and pxa2xx_ssp_get_clk_div() to align clk_div calculations, i.e. ssp_get_clk_div() and quark_x1000_set_clk_regvals() will return plain clk_div and it will be shifted to proper position in pxa2xx_ssp_get_clk_div(). Signed-off-by: Andy Shevchenko Signed-off-by: Mark Brown --- drivers/spi/spi-pxa2xx.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index 74342d167324..6d6473427432 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -726,23 +726,23 @@ static unsigned int ssp_get_clk_div(struct driver_data *drv_data, int rate) rate = min_t(int, ssp_clk, rate); if (ssp->type == PXA25x_SSP || ssp->type == CE4100_SSP) - return ((ssp_clk / (2 * rate) - 1) & 0xff) << 8; + return (ssp_clk / (2 * rate) - 1) & 0xff; else - return ((ssp_clk / rate - 1) & 0xfff) << 8; + return (ssp_clk / rate - 1) & 0xfff; } static unsigned int pxa2xx_ssp_get_clk_div(struct driver_data *drv_data, struct chip_data *chip, int rate) { - u32 clk_div; + unsigned int clk_div; switch (drv_data->ssp_type) { case QUARK_X1000_SSP: quark_x1000_set_clk_regvals(rate, &chip->dds_rate, &clk_div); - return clk_div << 8; default: - return ssp_get_clk_div(drv_data, rate); + clk_div = ssp_get_clk_div(drv_data, rate); } + return clk_div << 8; } static void pump_transfers(unsigned long data) -- cgit v1.2.3 From 9df461eca18f5395ee84670cdba6755dddec1898 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Wed, 25 Mar 2015 15:06:16 +0200 Subject: spi: pxa2xx: replace ugly table by approximation The Quark SoC data sheet describes the baud rate setting using fractional divider. The subset of possible values represented by a table suggests that the divisor has one block that could divide by 5. This explains the number of the beast in some cases in the table. Thus, in this particular case the divisor can be evaluated as 5^i * 2^j * 2 * k, where i = [0, 1] j = [0, 23] k = [1, 256] There are few cases as mentioned in the data sheet, i.e. better form of the clock signal will be in case if DDS_CLK_RATE either 2^n or 2/5. It's also possible to use any value that is less or equal to 0x33333 (1/5/16 = 1/80). All three cases are compared to each other and the one that suits better is chosen by the approximation algorithm. Anyone can play with the script [1] that represents the algorithm. [1] https://gist.github.com/06b084488b3629898121 Signed-off-by: Andy Shevchenko Signed-off-by: Mark Brown --- drivers/spi/spi-pxa2xx.c | 176 ++++++++++++++++++++++++++++++----------------- 1 file changed, 114 insertions(+), 62 deletions(-) (limited to 'drivers') diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index 6d6473427432..60526a591742 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -63,54 +64,6 @@ MODULE_ALIAS("platform:pxa2xx-spi"); #define LPSS_TX_LOTHRESH_DFLT 160 #define LPSS_TX_HITHRESH_DFLT 224 -struct quark_spi_rate { - u32 bitrate; - u32 dds_clk_rate; - u32 clk_div; -}; - -/* - * 'rate', 'dds', 'clk_div' lookup table, which is defined in - * the Quark SPI datasheet. - */ -static const struct quark_spi_rate quark_spi_rate_table[] = { -/* bitrate, dds_clk_rate, clk_div */ - {50000000, 0x800000, 0}, - {40000000, 0x666666, 0}, - {25000000, 0x400000, 0}, - {20000000, 0x666666, 1}, - {16667000, 0x800000, 2}, - {13333000, 0x666666, 2}, - {12500000, 0x200000, 0}, - {10000000, 0x800000, 4}, - {8000000, 0x666666, 4}, - {6250000, 0x400000, 3}, - {5000000, 0x400000, 4}, - {4000000, 0x666666, 9}, - {3125000, 0x80000, 0}, - {2500000, 0x400000, 9}, - {2000000, 0x666666, 19}, - {1563000, 0x40000, 0}, - {1250000, 0x200000, 9}, - {1000000, 0x400000, 24}, - {800000, 0x666666, 49}, - {781250, 0x20000, 0}, - {625000, 0x200000, 19}, - {500000, 0x400000, 49}, - {400000, 0x666666, 99}, - {390625, 0x10000, 0}, - {250000, 0x400000, 99}, - {200000, 0x666666, 199}, - {195313, 0x8000, 0}, - {125000, 0x100000, 49}, - {100000, 0x200000, 124}, - {50000, 0x100000, 124}, - {25000, 0x80000, 124}, - {10016, 0x20000, 77}, - {5040, 0x20000, 154}, - {1002, 0x8000, 194}, -}; - /* Offset from drv_data->lpss_base */ #define GENERAL_REG 0x08 #define GENERAL_REG_RXTO_HOLDOFF_DISABLE BIT(24) @@ -697,25 +650,124 @@ static irqreturn_t ssp_int(int irq, void *dev_id) } /* - * The Quark SPI data sheet gives a table, and for the given 'rate', - * the 'dds' and 'clk_div' can be found in the table. + * The Quark SPI has an additional 24 bit register (DDS_CLK_RATE) to multiply + * input frequency by fractions of 2^24. It also has a divider by 5. + * + * There are formulas to get baud rate value for given input frequency and + * divider parameters, such as DDS_CLK_RATE and SCR: + * + * Fsys = 200MHz + * + * Fssp = Fsys * DDS_CLK_RATE / 2^24 (1) + * Baud rate = Fsclk = Fssp / (2 * (SCR + 1)) (2) + * + * DDS_CLK_RATE either 2^n or 2^n / 5. + * SCR is in range 0 .. 255 + * + * Divisor = 5^i * 2^j * 2 * k + * i = [0, 1] i = 1 iff j = 0 or j > 3 + * j = [0, 23] j = 0 iff i = 1 + * k = [1, 256] + * Special case: j = 0, i = 1: Divisor = 2 / 5 + * + * Accordingly to the specification the recommended values for DDS_CLK_RATE + * are: + * Case 1: 2^n, n = [0, 23] + * Case 2: 2^24 * 2 / 5 (0x666666) + * Case 3: less than or equal to 2^24 / 5 / 16 (0x33333) + * + * In all cases the lowest possible value is better. + * + * The function calculates parameters for all cases and chooses the one closest + * to the asked baud rate. */ -static u32 quark_x1000_set_clk_regvals(u32 rate, u32 *dds, u32 *clk_div) +static unsigned int quark_x1000_get_clk_div(int rate, u32 *dds) { - unsigned int i; - - for (i = 0; i < ARRAY_SIZE(quark_spi_rate_table); i++) { - if (rate >= quark_spi_rate_table[i].bitrate) { - *dds = quark_spi_rate_table[i].dds_clk_rate; - *clk_div = quark_spi_rate_table[i].clk_div; - return quark_spi_rate_table[i].bitrate; + unsigned long xtal = 200000000; + unsigned long fref = xtal / 2; /* mandatory division by 2, + see (2) */ + /* case 3 */ + unsigned long fref1 = fref / 2; /* case 1 */ + unsigned long fref2 = fref * 2 / 5; /* case 2 */ + unsigned long scale; + unsigned long q, q1, q2; + long r, r1, r2; + u32 mul; + + /* Case 1 */ + + /* Set initial value for DDS_CLK_RATE */ + mul = (1 << 24) >> 1; + + /* Calculate initial quot */ + q1 = DIV_ROUND_CLOSEST(fref1, rate); + + /* Scale q1 if it's too big */ + if (q1 > 256) { + /* Scale q1 to range [1, 512] */ + scale = fls_long(q1 - 1); + if (scale > 9) { + q1 >>= scale - 9; + mul >>= scale - 9; } + + /* Round the result if we have a remainder */ + q1 += q1 & 1; } - *dds = quark_spi_rate_table[i-1].dds_clk_rate; - *clk_div = quark_spi_rate_table[i-1].clk_div; + /* Decrease DDS_CLK_RATE as much as we can without loss in precision */ + scale = __ffs(q1); + q1 >>= scale; + mul >>= scale; + + /* Get the remainder */ + r1 = abs(fref1 / (1 << (24 - fls_long(mul))) / q1 - rate); + + /* Case 2 */ + + q2 = DIV_ROUND_CLOSEST(fref2, rate); + r2 = abs(fref2 / q2 - rate); + + /* + * Choose the best between two: less remainder we have the better. We + * can't go case 2 if q2 is greater than 256 since SCR register can + * hold only values 0 .. 255. + */ + if (r2 >= r1 || q2 > 256) { + /* case 1 is better */ + r = r1; + q = q1; + } else { + /* case 2 is better */ + r = r2; + q = q2; + mul = (1 << 24) * 2 / 5; + } + + /* Check case 3 only If the divisor is big enough */ + if (fref / rate >= 80) { + u64 fssp; + u32 m; + + /* Calculate initial quot */ + q1 = DIV_ROUND_CLOSEST(fref, rate); + m = (1 << 24) / q1; + + /* Get the remainder */ + fssp = (u64)fref * m; + do_div(fssp, 1 << 24); + r1 = abs(fssp - rate); + + /* Choose this one if it suits better */ + if (r1 < r) { + /* case 3 is better */ + q = 1; + mul = m; + } + } - return quark_spi_rate_table[i-1].bitrate; + *dds = mul; + return q - 1; } static unsigned int ssp_get_clk_div(struct driver_data *drv_data, int rate) @@ -738,7 +790,7 @@ static unsigned int pxa2xx_ssp_get_clk_div(struct driver_data *drv_data, switch (drv_data->ssp_type) { case QUARK_X1000_SSP: - quark_x1000_set_clk_regvals(rate, &chip->dds_rate, &clk_div); + clk_div = quark_x1000_get_clk_div(rate, &chip->dds_rate); default: clk_div = ssp_get_clk_div(drv_data, rate); } -- cgit v1.2.3 From eecacf73a40f37e74dc9d0453283c79b91f34d51 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Tue, 31 Mar 2015 16:49:38 +0300 Subject: spi: pxa2xx: missing break in pxa2xx_ssp_get_clk_div() We refactored this code but accidentally left out a break statement so QUARK_X1000_SSP isn't handled correctly. Fixes: 025ffe88ee60 ('spi: pxa2xx: shift clk_div in one place') Tested-by: Andy Shevchenko Signed-off-by: Dan Carpenter Signed-off-by: Mark Brown --- drivers/spi/spi-pxa2xx.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers') diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c index 60526a591742..e3223ac75a7c 100644 --- a/drivers/spi/spi-pxa2xx.c +++ b/drivers/spi/spi-pxa2xx.c @@ -791,8 +791,10 @@ static unsigned int pxa2xx_ssp_get_clk_div(struct driver_data *drv_data, switch (drv_data->ssp_type) { case QUARK_X1000_SSP: clk_div = quark_x1000_get_clk_div(rate, &chip->dds_rate); + break; default: clk_div = ssp_get_clk_div(drv_data, rate); + break; } return clk_div << 8; } -- cgit v1.2.3