From a8e3923ab57192547ffad01d78939c5c0d5d0c30 Mon Sep 17 00:00:00 2001 From: Sekhar Nori Date: Fri, 30 Mar 2018 20:00:51 +0530 Subject: [PATCH] mtd: rawnand: davinci: don't acquire and enable clock NAND itself is an asynchronous interface, it does not have any clock input. DaVinci NAND driver acquires clock for AEMIF (asynchronous external memory interface) which is an on-chip IP to which NAND is connected. The same clock is also enabled in AEMIF driver (either present drivers/memory or from machine code for some older platforms). AEMIF timing must be initialized before NAND can be accessed. This ensures that AEMIF clock is enabled too. Remove the superfluous clock acquisition and enable in DaVinci NAND driver. Tested on K2L, K2HK, K2E, DA850 EVM, DA850 LCDK in device-tree boot and DM644x EVM in legacy boot. Signed-off-by: Sekhar Nori Tested-by: Bartosz Golaszewski Signed-off-by: Boris Brezillon --- drivers/mtd/nand/raw/davinci_nand.c | 25 +------------------------ 1 file changed, 1 insertion(+), 24 deletions(-) diff --git a/drivers/mtd/nand/raw/davinci_nand.c b/drivers/mtd/nand/raw/davinci_nand.c index 0f09518d980f..7255a0d94374 100644 --- a/drivers/mtd/nand/raw/davinci_nand.c +++ b/drivers/mtd/nand/raw/davinci_nand.c @@ -27,7 +27,6 @@ #include #include #include -#include #include #include #include @@ -55,7 +54,6 @@ struct davinci_nand_info { struct nand_chip chip; struct device *dev; - struct clk *clk; bool is_readmode; @@ -703,22 +701,6 @@ static int nand_davinci_probe(struct platform_device *pdev) /* Use board-specific ECC config */ info->chip.ecc.mode = pdata->ecc_mode; - ret = -EINVAL; - - info->clk = devm_clk_get(&pdev->dev, "aemif"); - if (IS_ERR(info->clk)) { - ret = PTR_ERR(info->clk); - dev_dbg(&pdev->dev, "unable to get AEMIF clock, err %d\n", ret); - return ret; - } - - ret = clk_prepare_enable(info->clk); - if (ret < 0) { - dev_dbg(&pdev->dev, "unable to enable AEMIF clock, err %d\n", - ret); - goto err_clk_enable; - } - spin_lock_irq(&davinci_nand_lock); /* put CSxNAND into NAND mode */ @@ -732,7 +714,7 @@ static int nand_davinci_probe(struct platform_device *pdev) ret = nand_scan_ident(mtd, pdata->mask_chipsel ? 2 : 1, NULL); if (ret < 0) { dev_dbg(&pdev->dev, "no NAND chip(s) found\n"); - goto err; + return ret; } switch (info->chip.ecc.mode) { @@ -838,9 +820,6 @@ err_cleanup_nand: nand_cleanup(&info->chip); err: - clk_disable_unprepare(info->clk); - -err_clk_enable: spin_lock_irq(&davinci_nand_lock); if (info->chip.ecc.mode == NAND_ECC_HW_SYNDROME) ecc4_busy = false; @@ -859,8 +838,6 @@ static int nand_davinci_remove(struct platform_device *pdev) nand_release(nand_to_mtd(&info->chip)); - clk_disable_unprepare(info->clk); - return 0; }