diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-02 17:26:42 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-10-02 17:26:42 -0700 |
commit | 7fe0b14b725d6d09a1d9e1409bd465cb88b587f9 (patch) | |
tree | 89b5ffca03145618da92c75fb3cc1dda87dbb924 /drivers/clk | |
parent | 7a9a2970b5c1c2ce73d4bb84edaa7ebf13e0c841 (diff) | |
parent | 536a53a300d0d40152796eefb0a9e6e36ca37f7d (diff) | |
download | linux-7fe0b14b725d6d09a1d9e1409bd465cb88b587f9.tar.bz2 |
Merge tag 'spi-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/misc
Pull spi updates from Mark Brown:
"No framework work here, only a bunch of driver updates of varying
sizes:
- Factoring out of the core hardware support from the MXS MMC driver
by Marek Vasut to allow the hardware to also be used for SPI.
- Lots of error handling cleanups from Guenter Roeck
- Removal of the existing Tegra driver which is quite comprehensively
broken as detailed in the changelog for the removal.
- DT suppport for the PL022 and GPIO drivers.
- pinctrl support for OMAP and PL022."
Pulling from Mark Brown as Grant Likely is still busy moving.
* tag 'spi-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/misc: (53 commits)
spi: remove completely broken Tegra driver
spi/imx: set the inactive state of the clock according to the clock polarity
spi/pl022: get/put resources on suspend/resume
spi/pl022: use more managed resources
spi/pl022: Devicetree support w/o platform data
spi/s3c64xx: Don't free controller_data on non-dt platforms
spi: omap2-mcspi: add pinctrl support
spi/pl022: adopt pinctrl support
spi: omap2-mcspi: Cleanup the omap2_mcspi_txrx_dma function
spi/gpio: Fix stub for spi_gpio_probe_dt()
spi/mxs: Make the SPI block clock speed configurable via DT
spi: spi-sh-hspi: drop frees of devm_ alloc'd data
spi/pl022: Fix chipselects pointer computation
spi: spi-tle62x0: Use module_spi_driver macro
mxs/spi: Rework the mxs_ssp_timeout to be more readable
mxs/spi: Decrement the DMA/PIO border
mxs/spi: Increment the transfer length only if transfer succeeded
mxs/spi: Fix issues when doing long continuous transfer
spi: spi-gpio: Add DT bindings
spi: spi-gpio: store chipselect information in private structure
...
Diffstat (limited to 'drivers/clk')
-rw-r--r-- | drivers/clk/mxs/Makefile | 2 | ||||
-rw-r--r-- | drivers/clk/mxs/clk-ssp.c | 62 |
2 files changed, 63 insertions, 1 deletions
diff --git a/drivers/clk/mxs/Makefile b/drivers/clk/mxs/Makefile index 7bedeec08524..a6a22237e860 100644 --- a/drivers/clk/mxs/Makefile +++ b/drivers/clk/mxs/Makefile @@ -2,7 +2,7 @@ # Makefile for mxs specific clk # -obj-y += clk.o clk-pll.o clk-ref.o clk-div.o clk-frac.o +obj-y += clk.o clk-pll.o clk-ref.o clk-div.o clk-frac.o clk-ssp.o obj-$(CONFIG_SOC_IMX23) += clk-imx23.o obj-$(CONFIG_SOC_IMX28) += clk-imx28.o diff --git a/drivers/clk/mxs/clk-ssp.c b/drivers/clk/mxs/clk-ssp.c new file mode 100644 index 000000000000..af7bdbf9ebd7 --- /dev/null +++ b/drivers/clk/mxs/clk-ssp.c @@ -0,0 +1,62 @@ +/* + * Copyright 2012 DENX Software Engineering, GmbH + * + * Pulled from code: + * Portions copyright (C) 2003 Russell King, PXA MMCI Driver + * Portions copyright (C) 2004-2005 Pierre Ossman, W83L51xD SD/MMC driver + * + * Copyright 2008 Embedded Alley Solutions, Inc. + * Copyright 2009-2011 Freescale Semiconductor, Inc. + * + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/clk.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/io.h> +#include <linux/spi/mxs-spi.h> + +void mxs_ssp_set_clk_rate(struct mxs_ssp *ssp, unsigned int rate) +{ + unsigned int ssp_clk, ssp_sck; + u32 clock_divide, clock_rate; + u32 val; + + ssp_clk = clk_get_rate(ssp->clk); + + for (clock_divide = 2; clock_divide <= 254; clock_divide += 2) { + clock_rate = DIV_ROUND_UP(ssp_clk, rate * clock_divide); + clock_rate = (clock_rate > 0) ? clock_rate - 1 : 0; + if (clock_rate <= 255) + break; + } + + if (clock_divide > 254) { + dev_err(ssp->dev, + "%s: cannot set clock to %d\n", __func__, rate); + return; + } + + ssp_sck = ssp_clk / clock_divide / (1 + clock_rate); + + val = readl(ssp->base + HW_SSP_TIMING(ssp)); + val &= ~(BM_SSP_TIMING_CLOCK_DIVIDE | BM_SSP_TIMING_CLOCK_RATE); + val |= BF_SSP(clock_divide, TIMING_CLOCK_DIVIDE); + val |= BF_SSP(clock_rate, TIMING_CLOCK_RATE); + writel(val, ssp->base + HW_SSP_TIMING(ssp)); + + ssp->clk_rate = ssp_sck; + + dev_dbg(ssp->dev, + "%s: clock_divide %d, clock_rate %d, ssp_clk %d, rate_actual %d, rate_requested %d\n", + __func__, clock_divide, clock_rate, ssp_clk, ssp_sck, rate); +} +EXPORT_SYMBOL_GPL(mxs_ssp_set_clk_rate); |