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