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authorMarek Vasut <marex@denx.de>2012-08-03 11:26:10 -0400
committerMark Brown <broonie@opensource.wolfsonmicro.com>2012-08-17 17:53:00 -0400
commit1308239858c33feeeb67003d08c754ee181f33cf (patch)
treebc74532d1085d85776c2dde1183996f5baeddcf9
parent829c1bf40b926a86e545733f6252262add3abe39 (diff)
mmc: spi: Pull out the SSP clock configuration function
Pull out the MMC clock configuration function and make it into SSP clock configuration function, so it can be used by the SPI driver too. Signed-off-by: Marek Vasut <marex@denx.de> Acked-by: Chris Ball <cjb@laptop.org> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
-rw-r--r--drivers/clk/mxs/Makefile2
-rw-r--r--drivers/clk/mxs/clk-ssp.c62
-rw-r--r--drivers/mmc/host/mxs-mmc.c39
-rw-r--r--include/linux/spi/mxs-spi.h2
4 files changed, 66 insertions, 39 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 @@
2# Makefile for mxs specific clk 2# Makefile for mxs specific clk
3# 3#
4 4
5obj-y += clk.o clk-pll.o clk-ref.o clk-div.o clk-frac.o 5obj-y += clk.o clk-pll.o clk-ref.o clk-div.o clk-frac.o clk-ssp.o
6 6
7obj-$(CONFIG_SOC_IMX23) += clk-imx23.o 7obj-$(CONFIG_SOC_IMX23) += clk-imx23.o
8obj-$(CONFIG_SOC_IMX28) += clk-imx28.o 8obj-$(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 @@
1/*
2 * Copyright 2012 DENX Software Engineering, GmbH
3 *
4 * Pulled from code:
5 * Portions copyright (C) 2003 Russell King, PXA MMCI Driver
6 * Portions copyright (C) 2004-2005 Pierre Ossman, W83L51xD SD/MMC driver
7 *
8 * Copyright 2008 Embedded Alley Solutions, Inc.
9 * Copyright 2009-2011 Freescale Semiconductor, Inc.
10 *
11 * The code contained herein is licensed under the GNU General Public
12 * License. You may obtain a copy of the GNU General Public License
13 * Version 2 or later at the following locations:
14 *
15 * http://www.opensource.org/licenses/gpl-license.html
16 * http://www.gnu.org/copyleft/gpl.html
17 */
18
19#include <linux/kernel.h>
20#include <linux/init.h>
21#include <linux/clk.h>
22#include <linux/module.h>
23#include <linux/device.h>
24#include <linux/io.h>
25#include <linux/spi/mxs-spi.h>
26
27void mxs_ssp_set_clk_rate(struct mxs_ssp *ssp, unsigned int rate)
28{
29 unsigned int ssp_clk, ssp_sck;
30 u32 clock_divide, clock_rate;
31 u32 val;
32
33 ssp_clk = clk_get_rate(ssp->clk);
34
35 for (clock_divide = 2; clock_divide <= 254; clock_divide += 2) {
36 clock_rate = DIV_ROUND_UP(ssp_clk, rate * clock_divide);
37 clock_rate = (clock_rate > 0) ? clock_rate - 1 : 0;
38 if (clock_rate <= 255)
39 break;
40 }
41
42 if (clock_divide > 254) {
43 dev_err(ssp->dev,
44 "%s: cannot set clock to %d\n", __func__, rate);
45 return;
46 }
47
48 ssp_sck = ssp_clk / clock_divide / (1 + clock_rate);
49
50 val = readl(ssp->base + HW_SSP_TIMING(ssp));
51 val &= ~(BM_SSP_TIMING_CLOCK_DIVIDE | BM_SSP_TIMING_CLOCK_RATE);
52 val |= BF_SSP(clock_divide, TIMING_CLOCK_DIVIDE);
53 val |= BF_SSP(clock_rate, TIMING_CLOCK_RATE);
54 writel(val, ssp->base + HW_SSP_TIMING(ssp));
55
56 ssp->clk_rate = ssp_sck;
57
58 dev_dbg(ssp->dev,
59 "%s: clock_divide %d, clock_rate %d, ssp_clk %d, rate_actual %d, rate_requested %d\n",
60 __func__, clock_divide, clock_rate, ssp_clk, ssp_sck, rate);
61}
62EXPORT_SYMBOL_GPL(mxs_ssp_set_clk_rate);
diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c
index 7b85e035a4cb..0813340fa29c 100644
--- a/drivers/mmc/host/mxs-mmc.c
+++ b/drivers/mmc/host/mxs-mmc.c
@@ -501,43 +501,6 @@ static void mxs_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
501 mxs_mmc_start_cmd(host, mrq->cmd); 501 mxs_mmc_start_cmd(host, mrq->cmd);
502} 502}
503 503
504static void mxs_mmc_set_clk_rate(struct mxs_mmc_host *host, unsigned int rate)
505{
506 struct mxs_ssp *ssp = &host->ssp;
507 unsigned int ssp_clk, ssp_sck;
508 u32 clock_divide, clock_rate;
509 u32 val;
510
511 ssp_clk = clk_get_rate(ssp->clk);
512
513 for (clock_divide = 2; clock_divide <= 254; clock_divide += 2) {
514 clock_rate = DIV_ROUND_UP(ssp_clk, rate * clock_divide);
515 clock_rate = (clock_rate > 0) ? clock_rate - 1 : 0;
516 if (clock_rate <= 255)
517 break;
518 }
519
520 if (clock_divide > 254) {
521 dev_err(mmc_dev(host->mmc),
522 "%s: cannot set clock to %d\n", __func__, rate);
523 return;
524 }
525
526 ssp_sck = ssp_clk / clock_divide / (1 + clock_rate);
527
528 val = readl(ssp->base + HW_SSP_TIMING(ssp));
529 val &= ~(BM_SSP_TIMING_CLOCK_DIVIDE | BM_SSP_TIMING_CLOCK_RATE);
530 val |= BF_SSP(clock_divide, TIMING_CLOCK_DIVIDE);
531 val |= BF_SSP(clock_rate, TIMING_CLOCK_RATE);
532 writel(val, ssp->base + HW_SSP_TIMING(ssp));
533
534 ssp->clk_rate = ssp_sck;
535
536 dev_dbg(mmc_dev(host->mmc),
537 "%s: clock_divide %d, clock_rate %d, ssp_clk %d, rate_actual %d, rate_requested %d\n",
538 __func__, clock_divide, clock_rate, ssp_clk, ssp_sck, rate);
539}
540
541static void mxs_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) 504static void mxs_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
542{ 505{
543 struct mxs_mmc_host *host = mmc_priv(mmc); 506 struct mxs_mmc_host *host = mmc_priv(mmc);
@@ -550,7 +513,7 @@ static void mxs_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
550 host->bus_width = 0; 513 host->bus_width = 0;
551 514
552 if (ios->clock) 515 if (ios->clock)
553 mxs_mmc_set_clk_rate(host, ios->clock); 516 mxs_ssp_set_clk_rate(&host->ssp, ios->clock);
554} 517}
555 518
556static void mxs_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable) 519static void mxs_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
diff --git a/include/linux/spi/mxs-spi.h b/include/linux/spi/mxs-spi.h
index 475f69fb896f..d07f8dc7fdd9 100644
--- a/include/linux/spi/mxs-spi.h
+++ b/include/linux/spi/mxs-spi.h
@@ -136,4 +136,6 @@ struct mxs_ssp {
136 enum mxs_ssp_id devid; 136 enum mxs_ssp_id devid;
137}; 137};
138 138
139void mxs_ssp_set_clk_rate(struct mxs_ssp *ssp, unsigned int rate);
140
139#endif /* __LINUX_SPI_MXS_SPI_H__ */ 141#endif /* __LINUX_SPI_MXS_SPI_H__ */