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+/*
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+ * Copyright 2012 DENX Software Engineering, GmbH
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+ *
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+ * Pulled from code:
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+ * Portions copyright (C) 2003 Russell King, PXA MMCI Driver
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+ * Portions copyright (C) 2004-2005 Pierre Ossman, W83L51xD SD/MMC driver
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+ *
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+ * Copyright 2008 Embedded Alley Solutions, Inc.
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+ * Copyright 2009-2011 Freescale Semiconductor, Inc.
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+ *
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+ * The code contained herein is licensed under the GNU General Public
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+ * License. You may obtain a copy of the GNU General Public License
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+ * Version 2 or later at the following locations:
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+ *
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+ * http://www.opensource.org/licenses/gpl-license.html
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+ * http://www.gnu.org/copyleft/gpl.html
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+ */
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+
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+#include <linux/kernel.h>
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+#include <linux/init.h>
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+#include <linux/clk.h>
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+#include <linux/module.h>
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+#include <linux/device.h>
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+#include <linux/io.h>
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+#include <linux/spi/mxs-spi.h>
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+
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+void mxs_ssp_set_clk_rate(struct mxs_ssp *ssp, unsigned int rate)
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+{
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+ unsigned int ssp_clk, ssp_sck;
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+ u32 clock_divide, clock_rate;
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+ u32 val;
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+
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+ ssp_clk = clk_get_rate(ssp->clk);
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+
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+ for (clock_divide = 2; clock_divide <= 254; clock_divide += 2) {
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+ clock_rate = DIV_ROUND_UP(ssp_clk, rate * clock_divide);
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+ clock_rate = (clock_rate > 0) ? clock_rate - 1 : 0;
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+ if (clock_rate <= 255)
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+ break;
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+ }
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+
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+ if (clock_divide > 254) {
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+ dev_err(ssp->dev,
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+ "%s: cannot set clock to %d\n", __func__, rate);
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+ return;
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+ }
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+
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+ ssp_sck = ssp_clk / clock_divide / (1 + clock_rate);
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+
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+ val = readl(ssp->base + HW_SSP_TIMING(ssp));
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+ val &= ~(BM_SSP_TIMING_CLOCK_DIVIDE | BM_SSP_TIMING_CLOCK_RATE);
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+ val |= BF_SSP(clock_divide, TIMING_CLOCK_DIVIDE);
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+ val |= BF_SSP(clock_rate, TIMING_CLOCK_RATE);
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+ writel(val, ssp->base + HW_SSP_TIMING(ssp));
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+
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+ ssp->clk_rate = ssp_sck;
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+
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+ dev_dbg(ssp->dev,
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+ "%s: clock_divide %d, clock_rate %d, ssp_clk %d, rate_actual %d, rate_requested %d\n",
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+ __func__, clock_divide, clock_rate, ssp_clk, ssp_sck, rate);
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+}
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+EXPORT_SYMBOL_GPL(mxs_ssp_set_clk_rate);
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