From 1dc338e856744b8ca62addd1e29cc25fe6aae14d Mon Sep 17 00:00:00 2001 From: Rostislav Lisovy Date: Wed, 29 Oct 2014 11:10:59 +0100 Subject: [PATCH] mtd: nand: omap: Synchronize the access to the ECC engine The AM335x Technical Reference Manual (spruh73j.pdf) says "Because the ECC engine includes only one accumulation context, it can be allocated to only one chip-select at a time ... " (7.1.3.3.12.3). Since the commit 97a288ba2cfa ("ARM: omap2+: gpmc-nand: Use dynamic platform_device_alloc()") gpmc-nand driver supports multiple NAND flash devices connected to the single controller. Use global 'struct nand_hw_control' among multiple NAND instances to synchronize the access to the single ECC Engine. Tested with custom AM335x board using 2x NAND flash chips. Signed-off-by: Rostislav Lisovy Acked-by: Roger Quadros Signed-off-by: Brian Norris --- drivers/mtd/nand/omap2.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index b0f89d87de89..1ec0a1dbed3d 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -144,8 +144,13 @@ static u_char bch8_vector[] = {0xf3, 0xdb, 0x14, 0x16, 0x8b, 0xd2, 0xbe, 0xcc, 0xac, 0x6b, 0xff, 0x99, 0x7b}; static u_char bch4_vector[] = {0x00, 0x6b, 0x31, 0xdd, 0x41, 0xbc, 0x10}; +/* Shared among all NAND instances to synchronize access to the ECC Engine */ +static struct nand_hw_control omap_gpmc_controller = { + .lock = __SPIN_LOCK_UNLOCKED(omap_gpmc_controller.lock), + .wq = __WAIT_QUEUE_HEAD_INITIALIZER(omap_gpmc_controller.wq), +}; + struct omap_nand_info { - struct nand_hw_control controller; struct omap_nand_platform_data *pdata; struct mtd_info mtd; struct nand_chip nand; @@ -1685,9 +1690,6 @@ static int omap_nand_probe(struct platform_device *pdev) platform_set_drvdata(pdev, info); - spin_lock_init(&info->controller.lock); - init_waitqueue_head(&info->controller.wq); - info->pdev = pdev; info->gpmc_cs = pdata->cs; info->reg = pdata->reg; @@ -1707,7 +1709,7 @@ static int omap_nand_probe(struct platform_device *pdev) info->phys_base = res->start; - nand_chip->controller = &info->controller; + nand_chip->controller = &omap_gpmc_controller; nand_chip->IO_ADDR_W = nand_chip->IO_ADDR_R; nand_chip->cmd_ctrl = omap_hwcontrol; -- GitLab