mtd: nand: omap: Synchronize the access to the ECC engine (1dc338e8) · Commits · 戴 / test

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 ("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 <lisovy@merica.cz> Acked-by:

Roger Quadros <rogerq@ti.com> Signed-off-by:

Brian Norris <computersforpeace@gmail.com>

drivers/mtd/nand/omap2.c

+7 −5

Original line number	Diff line number	Diff line
		@@ -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;

Admin message