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![Ivan Khoronzhuk](/assets/img/avatar_default.png)
The problem that the set timings code contains the call of Davinci platform function davinci_aemif_setup_timing() which is not accessible if kernel is built for another platform like Keystone. The Keysone platform is going to use TI AEMIF driver. If TI AEMIF is used we don't need to set timings and bus width. It is done by AEMIF driver. To get rid of davinci-nand driver dependency on aemif platform code we moved aemif code to davinci platform. The platform AEMIF code (aemif.c) has to be removed once Davinci will be converted to DT and use ti-aemif.c driver. Acked-by: Brian Norris <computersforpeace@gmail.com> Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com> [nsekhar@ti.com: fixed checkpatch error and a build breakage due to missing include, rebased onto l2-mtd/master] Signed-off-by: Sekhar Nori <nsekhar@ti.com>
218 lines
5.8 KiB
C
218 lines
5.8 KiB
C
/*
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* AEMIF support for DaVinci SoCs
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*
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* Copyright (C) 2010 Texas Instruments Incorporated. http://www.ti.com/
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/io.h>
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#include <linux/err.h>
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#include <linux/clk.h>
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#include <linux/module.h>
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#include <linux/time.h>
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#include <linux/platform_data/mtd-davinci-aemif.h>
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#include <linux/platform_data/mtd-davinci.h>
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/* Timing value configuration */
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#define TA(x) ((x) << 2)
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#define RHOLD(x) ((x) << 4)
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#define RSTROBE(x) ((x) << 7)
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#define RSETUP(x) ((x) << 13)
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#define WHOLD(x) ((x) << 17)
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#define WSTROBE(x) ((x) << 20)
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#define WSETUP(x) ((x) << 26)
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#define TA_MAX 0x3
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#define RHOLD_MAX 0x7
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#define RSTROBE_MAX 0x3f
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#define RSETUP_MAX 0xf
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#define WHOLD_MAX 0x7
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#define WSTROBE_MAX 0x3f
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#define WSETUP_MAX 0xf
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#define TIMING_MASK (TA(TA_MAX) | \
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RHOLD(RHOLD_MAX) | \
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RSTROBE(RSTROBE_MAX) | \
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RSETUP(RSETUP_MAX) | \
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WHOLD(WHOLD_MAX) | \
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WSTROBE(WSTROBE_MAX) | \
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WSETUP(WSETUP_MAX))
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static inline unsigned int davinci_aemif_readl(void __iomem *base, int offset)
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{
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return readl_relaxed(base + offset);
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}
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static inline void davinci_aemif_writel(void __iomem *base,
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int offset, unsigned long value)
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{
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writel_relaxed(value, base + offset);
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}
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/*
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* aemif_calc_rate - calculate timing data.
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* @wanted: The cycle time needed in nanoseconds.
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* @clk: The input clock rate in kHz.
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* @max: The maximum divider value that can be programmed.
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*
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* On success, returns the calculated timing value minus 1 for easy
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* programming into AEMIF timing registers, else negative errno.
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*/
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static int aemif_calc_rate(int wanted, unsigned long clk, int max)
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{
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int result;
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result = DIV_ROUND_UP((wanted * clk), NSEC_PER_MSEC) - 1;
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pr_debug("%s: result %d from %ld, %d\n", __func__, result, clk, wanted);
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/* It is generally OK to have a more relaxed timing than requested... */
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if (result < 0)
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result = 0;
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/* ... But configuring tighter timings is not an option. */
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else if (result > max)
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result = -EINVAL;
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return result;
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}
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/**
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* davinci_aemif_setup_timing - setup timing values for a given AEMIF interface
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* @t: timing values to be progammed
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* @base: The virtual base address of the AEMIF interface
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* @cs: chip-select to program the timing values for
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* @clkrate: the AEMIF clkrate
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*
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* This function programs the given timing values (in real clock) into the
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* AEMIF registers taking the AEMIF clock into account.
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*
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* This function does not use any locking while programming the AEMIF
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* because it is expected that there is only one user of a given
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* chip-select.
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*
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* Returns 0 on success, else negative errno.
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*/
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static int davinci_aemif_setup_timing(struct davinci_aemif_timing *t,
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void __iomem *base, unsigned cs,
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unsigned long clkrate)
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{
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unsigned set, val;
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int ta, rhold, rstrobe, rsetup, whold, wstrobe, wsetup;
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unsigned offset = A1CR_OFFSET + cs * 4;
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if (!t)
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return 0; /* Nothing to do */
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clkrate /= 1000; /* turn clock into kHz for ease of use */
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ta = aemif_calc_rate(t->ta, clkrate, TA_MAX);
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rhold = aemif_calc_rate(t->rhold, clkrate, RHOLD_MAX);
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rstrobe = aemif_calc_rate(t->rstrobe, clkrate, RSTROBE_MAX);
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rsetup = aemif_calc_rate(t->rsetup, clkrate, RSETUP_MAX);
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whold = aemif_calc_rate(t->whold, clkrate, WHOLD_MAX);
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wstrobe = aemif_calc_rate(t->wstrobe, clkrate, WSTROBE_MAX);
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wsetup = aemif_calc_rate(t->wsetup, clkrate, WSETUP_MAX);
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if (ta < 0 || rhold < 0 || rstrobe < 0 || rsetup < 0 ||
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whold < 0 || wstrobe < 0 || wsetup < 0) {
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pr_err("%s: cannot get suitable timings\n", __func__);
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return -EINVAL;
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}
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set = TA(ta) | RHOLD(rhold) | RSTROBE(rstrobe) | RSETUP(rsetup) |
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WHOLD(whold) | WSTROBE(wstrobe) | WSETUP(wsetup);
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val = __raw_readl(base + offset);
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val &= ~TIMING_MASK;
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val |= set;
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__raw_writel(val, base + offset);
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return 0;
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}
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/**
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* davinci_aemif_setup - setup AEMIF interface by davinci_nand_pdata
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* @pdev - link to platform device to setup settings for
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*
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* This function does not use any locking while programming the AEMIF
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* because it is expected that there is only one user of a given
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* chip-select.
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*
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* Returns 0 on success, else negative errno.
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*/
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int davinci_aemif_setup(struct platform_device *pdev)
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{
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struct davinci_nand_pdata *pdata = dev_get_platdata(&pdev->dev);
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uint32_t val;
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unsigned long clkrate;
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struct resource *res;
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void __iomem *base;
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struct clk *clk;
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int ret = 0;
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clk = clk_get(&pdev->dev, "aemif");
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if (IS_ERR(clk)) {
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ret = PTR_ERR(clk);
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dev_dbg(&pdev->dev, "unable to get AEMIF clock, err %d\n", ret);
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return ret;
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}
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ret = clk_prepare_enable(clk);
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if (ret < 0) {
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dev_dbg(&pdev->dev, "unable to enable AEMIF clock, err %d\n",
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ret);
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goto err_put;
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}
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res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
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if (!res) {
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dev_err(&pdev->dev, "cannot get IORESOURCE_MEM\n");
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ret = -ENOMEM;
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goto err;
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}
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base = ioremap(res->start, resource_size(res));
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if (!base) {
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dev_err(&pdev->dev, "ioremap failed for resource %pR\n", res);
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ret = -ENOMEM;
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goto err;
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}
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/*
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* Setup Async configuration register in case we did not boot
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* from NAND and so bootloader did not bother to set it up.
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*/
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val = davinci_aemif_readl(base, A1CR_OFFSET + pdev->id * 4);
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/*
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* Extended Wait is not valid and Select Strobe mode is not
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* used
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*/
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val &= ~(ACR_ASIZE_MASK | ACR_EW_MASK | ACR_SS_MASK);
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if (pdata->options & NAND_BUSWIDTH_16)
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val |= 0x1;
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davinci_aemif_writel(base, A1CR_OFFSET + pdev->id * 4, val);
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clkrate = clk_get_rate(clk);
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if (pdata->timing)
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ret = davinci_aemif_setup_timing(pdata->timing, base, pdev->id,
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clkrate);
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if (ret < 0)
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dev_dbg(&pdev->dev, "NAND timing values setup fail\n");
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iounmap(base);
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err:
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clk_disable_unprepare(clk);
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err_put:
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clk_put(clk);
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return ret;
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}
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