diff options
Diffstat (limited to 'arch/arm/mach-davinci/aemif.c')
-rw-r--r-- | arch/arm/mach-davinci/aemif.c | 107 |
1 files changed, 96 insertions, 11 deletions
diff --git a/arch/arm/mach-davinci/aemif.c b/arch/arm/mach-davinci/aemif.c index f091a9010c2..ff8b7e76b6e 100644 --- a/arch/arm/mach-davinci/aemif.c +++ b/arch/arm/mach-davinci/aemif.c @@ -16,6 +16,7 @@ #include <linux/time.h> #include <linux/platform_data/mtd-davinci-aemif.h> +#include <linux/platform_data/mtd-davinci.h> /* Timing value configuration */ @@ -43,6 +44,17 @@ 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. @@ -76,6 +88,7 @@ static int aemif_calc_rate(int wanted, unsigned long clk, int max) * @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. @@ -86,24 +99,17 @@ static int aemif_calc_rate(int wanted, unsigned long clk, int max) * * Returns 0 on success, else negative errno. */ -int davinci_aemif_setup_timing(struct davinci_aemif_timing *t, - void __iomem *base, unsigned cs) +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; - struct clk *aemif_clk; - unsigned long clkrate; if (!t) return 0; /* Nothing to do */ - aemif_clk = clk_get(NULL, "aemif"); - if (IS_ERR(aemif_clk)) - return PTR_ERR(aemif_clk); - - clkrate = clk_get_rate(aemif_clk); - clkrate /= 1000; /* turn clock into kHz for ease of use */ ta = aemif_calc_rate(t->ta, clkrate, TA_MAX); @@ -130,4 +136,83 @@ int davinci_aemif_setup_timing(struct davinci_aemif_timing *t, return 0; } -EXPORT_SYMBOL(davinci_aemif_setup_timing); + +/** + * 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 + pdev->id * 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 + pdev->id * 4, val); + + clkrate = clk_get_rate(clk); + + if (pdata->timing) + ret = davinci_aemif_setup_timing(pdata->timing, base, pdev->id, + 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; +} |