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path: root/drivers/spi/spi_mpc83xx.c
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2008-07-24spi: spi_mpc83xx clockrate fixesChen Gong1-13/+16
This updates the SPI clock rate calculations for the spi_mpc83xx driver. Some boundary conditions were wrong, and in several cases divide-by-16 wasn't always needed Signed-off-by: Chen Gong <g.chen@freescale.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-05-13spi_mpc83xx: much improved driverJoakim Tjernlund1-129/+282
The current driver may cause glitches on SPI CLK line since one must disable the SPI controller before changing any HW settings. Fix this by implementing a local spi_transfer function that won't change speed and/or word size while CS is active. While doing that heavy lifting a few other issues were addressed too: - Make word size 16 and 32 work too. - Honor bits_per_word and speed_hz in spi transaction. - Optimize the common path. This also stops using the "bitbang" framework (except for a few constants). [Roel Kluin <12o3l@tiscali.nl>: "irq" needs to be signed] Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28spi: replace remaining __FUNCTION__ occurrencesHarvey Harrison1-1/+1
__FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-11spi: fix platform driver hotplug/coldplugKay Sievers1-2/+3
Since 43cc71eed1250755986da4c0f9898f9a635cb3bf, the platform modalias is prefixed with "platform:". Add MODULE_ALIAS() to the hotpluggable SPI platform drivers, to allow module auto loading. [dbrownell@users.sourceforge.net: more drivers: registration fixes] Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-28spi_mpc83xx: use brg-frequency for SPI in QEAnton Vorontsov1-5/+1
In case of QE we can use brg-frequency (which is qeclk/2). Thus no need to divide sysclk in the spi_mpc83xx. This patch also adds code to use get_brgfreq() on QE chips. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Acked-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2007-10-16SPI driver runtime footprint shrinkageDavid Brownell1-4/+3
Shrink the runtime footprint of various SPI drivers: - Move the probe() routine into the init section where practical, using platform_driver_probe() to make that safe. This often saves around 1KB. Using platform_driver_probe() can also be a correctness fix, if the probe routine is already marked __init but the driver struct keeps a dangling pointer to it after init section removal. - Likewise move remove() routines into the exit sections. These changes would be inappropriate iff the platform devices were actually hotpluggable (e.g. they're found on optional addon cards, or in an FPGA that's dynamically reprogrammed). In these cases, that's not the situation; it's an SOC controller and the only device is initialized before these drivers. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-09-11spi_mpc83xx: hang fixJan Andersson1-5/+2
When the spi_mpc83xx driver receives a tx_buf pointer which is NULL, it only writes one zero filled word to the transmit register. If the driver expects to receive more than one word it will wait forever for a second receive interrupt. With this patch the controller will shift out zeroes until all words have been received. Signed-off-by: Jan Andersson <jan@gaisler.com> Tested-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-31SPI driver hotplug/coldplug fixesDavid Brownell1-0/+1
Update various SPI drivers so they properly support - coldplug through "modprobe $(cat /sys/devices/.../modalias)" - hotplug through "modprobe $(MODALIAS)" The basic rule for platform, SPI, and (new style) I2C drivers is just to make sure that modprobing the driver name works. In this case, all the relevant drivers are platform drivers, and this patch either (a) Changes the driver name, if no in-tree code would break; this is simpler and thus preferable in the long term. (b) Adds MODULE_ALIAS directives, when in-tree platforms declare devices using the current driver name; less desirable. Most systems will link SPI controller drivers statically, but there's no point in being needlessly broken. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Jean Delvare <khali@linux-fr.org> Acked-by: Andrei Konovalov <akonovalov@ru.mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-11spi_mpc83xx: fix prescale modulus calculationAnton Vorontsov1-2/+6
Long ago I've noticed (but didn't pay much attention) that spi_mpc83xx using PM calculations that differs from what specs describe. I.e. u8 pm = mpc83xx_spi->spibrg / (spi->max_speed_hz * 4); While specs says: "The SPI baud rate generator clock source (either system clock or system clock divided by 16, depending on DIV16 bit) is divided by 4 * ([PM] + 1), a range from 4 to 64.". Thus " - 1" is missing in the spi_mpc83xx's formula. Why nobody noticed that bug? Probably because sysclk usually less then user expects, e.g. you expect 200 MHz, but real clock is 198 MHz, and integer rounding helps when this formula is used. Suppose it's SPI in QE, SYSCLK at 198 MHz, thus SPIBRG at 99MHz, 25 MHz requested. PM = (99MHz / ( 25 MHz * 4 )), PM == 0, output SPICLK will be 24.75 MHz At lower frequencies this bug is more noticeable, though. And this bug shows itself in all its beauty if SYSCLK is equal or a bit more than you expect (200 MHz SYSCLK, 100 MHz SPIBRG): PM = (100MHz / ( 25 MHz * 4 )), PM == 1, output SPICLK will be 12.625 MHz! Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-08-11spi_mpc83xx: in "QE mode", use sysclk/2Anton Vorontsov1-8/+13
For MPC8349E input to the SPI Baud Rate Generator is SYSCLK, but it's SYSCLK/2 for MPC8323E (SPI in QE). Fix this, and remove confusion by renaming the mpc83xx_spi->sysclk member as mpc83xx_spi->spibrg. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31spi_mpc83xx: support loopback modeAnton Vorontsov1-2/+6
This exposes the hardware loopback mode to drivers, primarily for testing. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31spi_mpc83xx: fix QE+LSB mode shiftsAnton Vorontsov1-0/+8
spi_mpc83xx should use other shifts when running in QE+LSB mode. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31spi_mpc83xx: support for lsb-first transfersAnton Vorontsov1-5/+10
This controller supports LSB-first transfers; let drivers use them. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31spi_mpc83xx: get rid of magic numbersAnton Vorontsov1-2/+3
Magic-numbers-R-Evil Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31spi_mpc83xx: turn off SPI unit while switching modeAnton Vorontsov1-0/+4
Documentation clearly states, that mode should not be changed till SPMODE_ENABLE bit set. I've seen hangs w/o this patch. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Acked-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17spi_mpc83xx.c: support QE enabled 83xx CPU's like mpc832xJoakim Tjernlund1-3/+29
Quicc Engine enabled mpc83xx CPU's has a somewhat different HW interface to the SPI controller. This patch adds a qe_mode knob that sees to that needed adaptions are performed. Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17spi_mpc83xx.c underclocking hotfixClifford Wolf1-0/+6
The MPC83xx SPI controller clock divider can divide the system clock by not more then 1024. The spi_mpc83xx driver does not check this and silently writes garbage to the SPI controller registers when asked to run at lower frequencies. I've tried to run the SPI on a 266MHz MPC8349E with 100kHz for debugging a bus problem and suddenly was confronted with a 2nd problem to debug.. ;-) The patch adds an additional check which avoids writing garbage to the SPI controller registers and warn the user about it. This might help others to avoid simmilar problems. Cc: Kumar Gala <galak@gate.crashing.org> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17SPI controller drivers: check for unsupported modesDavid Brownell1-0/+9
Minor SPI controller driver updates: make the setup() methods reject spi->mode bits they don't support, by masking aginst the inverse of bits they *do* support. This insures against misbehavior later when new mode bits get added. Most controllers can't support SPI_LSB_FIRST; more handle SPI_CS_HIGH. Support for all four SPI clock/transfer modes is routine. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-30[PATCH] SPI: define null tx_buf to mean "shift out zeroes"David Brownell1-0/+2
Some issues were recently turned up with the current specification of what it means for spi_transfer.tx_buf to be null, as part of transfers which are (from the SPI protocol driver perspective) pure reads. Specifically, that it seems better to change the TX behaviour there from "undefined" to "will shift zeroes". This lets protocol drivers (like the ads7846 driver) depend on that behavior. It's what most controller drivers in the tree are already doing (with one exception and one case of driver wanting-to-oops), it's what Microwire hardware will necessarily be doing, and it removes an issue whereby certain security audits would need to define such a value anyway as part of removing covert channels. This patch changes the specification to require shifting zeroes, and updates all currently merged SPI controller drivers to do so. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-05IRQ: Maintain regs pointer globally rather than passing to IRQ handlersDavid Howells1-2/+1
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-05-21[PATCH] spi: add spi master driver for Freescale MPC83xx SPI controllerKumar Gala1-0/+483
This driver supports the SPI controller on the MPC83xx SoC devices from Freescale. Note, this driver supports only the simple shift register SPI controller and not the descriptor based CPM or QUICCEngine SPI controller. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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