Messages in this thread |  | | Subject | Re: [PATCH v9 2/3] mtd: nand: jz4780: driver for NAND devices on JZ4780 SoCs | | From | Harvey Hunt <> | | Date | Tue, 8 Dec 2015 16:36:12 +0000 |
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On 08/12/15 16:26, Boris Brezillon wrote: > On Tue, 8 Dec 2015 16:03:55 +0000 > Harvey Hunt <harvey.hunt@imgtec.com> wrote: > >>> >>> static void jz4780_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, >>> unsigned int ctrl) >>> { >>> struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd); >>> struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller); >>> struct jz4780_nand_cs *cs; >>> >>> if (WARN_ON(nfc->selected < 0)) >>> return; >>> >>> cs = &nfc->cs[nfc->selected]; >>> >>> if (ctrl & NAND_CTRL_CHANGE) { >>> if (cmd != NAND_CMD_NONE) { >>> if (ctrl & NAND_ALE) >>> writeb(cmd, cs->base + OFFSET_ADDR); >>> else if (ctrl & NAND_CLE) >>> writeb(cmd, cs->base + OFFSET_CMD); >>> } >>> >>> jz4780_nemc_assert(nfc->dev, cs->bank, ctrl & NAND_NCE); >>> } >>> } >>> >> >> Okay, I understand your point now. I would also have to implement the >> read/write functions to replace the defaults, correct? If so, it feels >> strange to add functions to reimplement the default ones. >> > > Actually it should be something like this, because NAND_CTRL_CHANGE is > cleared after the first address cycle. > > static void jz4780_nand_cmd_ctrl(struct mtd_info *mtd, int cmd, > unsigned int ctrl) > { > struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd); > struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller); > struct jz4780_nand_cs *cs; > > if (WARN_ON(nfc->selected < 0)) > return; > > cs = &nfc->cs[nfc->selected]; > > jz4780_nemc_assert(nfc->dev, cs->bank, ctrl & NAND_NCE); > > if (cmd == NAND_CMD_NONE) > return; > > if (ctrl & NAND_ALE) > writeb(cmd, cs->base + OFFSET_ADDR); > else if (ctrl & NAND_CLE) > writeb(cmd, cs->base + OFFSET_CMD); > } >
Thanks for the example code, I'll try it out for the next version.
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