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authorLinus Torvalds <torvalds@linux-foundation.org>2012-10-02 17:26:42 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-10-02 17:26:42 -0700
commit7fe0b14b725d6d09a1d9e1409bd465cb88b587f9 (patch)
tree89b5ffca03145618da92c75fb3cc1dda87dbb924 /drivers/clk/mxs
parent7a9a2970b5c1c2ce73d4bb84edaa7ebf13e0c841 (diff)
parent536a53a300d0d40152796eefb0a9e6e36ca37f7d (diff)
downloadlinux-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/mxs')
-rw-r--r--drivers/clk/mxs/Makefile2
-rw-r--r--drivers/clk/mxs/clk-ssp.c62
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);