From mboxrd@z Thu Jan 1 00:00:00 1970 From: Abhishek Sahu Subject: Re: [PATCH v4 11/20] mtd: nand: qcom: enable BAM or ADM mode Date: Wed, 16 Aug 2017 14:19:01 +0530 Message-ID: References: <1502451575-15712-1-git-send-email-absahu@codeaurora.org> <1502451575-15712-12-git-send-email-absahu@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Archit Taneja Cc: boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, computersforpeace-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, marek.vasut-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, richard-/L3Ra7n9ekc@public.gmane.org, cyrille.pitchen-yU5RGvR974pGWvitb5QawA@public.gmane.org, linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, andy.gross-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org List-Id: devicetree@vger.kernel.org On 2017-08-16 10:20, Archit Taneja wrote: > On 08/11/2017 05:09 PM, Abhishek Sahu wrote: >> 1. DM_EN is only required for EBI2 NAND controller which uses ADM >> 2. BAM mode will be disabled after power on reset which needs to >> be enabled before starting any BAM transfers. >> >> Signed-off-by: Abhishek Sahu >> --- >> drivers/mtd/nand/qcom_nandc.c | 17 ++++++++++++++--- >> 1 file changed, 14 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/mtd/nand/qcom_nandc.c >> b/drivers/mtd/nand/qcom_nandc.c >> index 3d9fd7f..ae873d3 100644 >> --- a/drivers/mtd/nand/qcom_nandc.c >> +++ b/drivers/mtd/nand/qcom_nandc.c >> @@ -163,6 +163,9 @@ >> #define NAND_DEV_CMD_VLD_VAL (READ_START_VLD | WRITE_START_VLD | \ >> ERASE_START_VLD | SEQ_READ_START_VLD) >> +/* NAND_CTRL bits */ >> +#define BAM_MODE_EN BIT(0) >> + >> /* >> * the NAND controller performs reads/writes with ECC in 516 byte >> chunks. >> * the driver calls the chunks 'step' or 'codeword' interchangeably >> @@ -1035,7 +1038,8 @@ static int read_id(struct qcom_nand_host *host, >> int column) >> nandc_set_reg(nandc, NAND_FLASH_CMD, FETCH_ID); >> nandc_set_reg(nandc, NAND_ADDR0, column); >> nandc_set_reg(nandc, NAND_ADDR1, 0); >> - nandc_set_reg(nandc, NAND_FLASH_CHIP_SELECT, DM_EN); >> + nandc_set_reg(nandc, NAND_FLASH_CHIP_SELECT, >> + nandc->props->is_bam ? 0 : DM_EN); > > I'm not sure why the above register was configured in read_id in the > first place. Would > it be required later if we want the controller to support multiple > NAND chips? If not, > then we could consider dropping this. Anyway, that can be posted as a > separate patch > later. Correct. It seems the current driver does not have fully support second NAND chip select since it need to program NAND_DEV1_CFG1 and NAND_DEV1_CFG0 also. We can have separate patch series which will add the full support for multiple NAND chips and this line can be removed in that patch series. > > Reviewed-by: Archit Taneja > > Thanks, > Archit > >> nandc_set_reg(nandc, NAND_EXEC_CMD, 1); >> write_reg_dma(nandc, NAND_FLASH_CMD, 4, NAND_BAM_NEXT_SGL); >> @@ -2408,12 +2412,19 @@ static void qcom_nandc_unalloc(struct >> qcom_nand_controller *nandc) >> /* one time setup of a few nand controller registers */ >> static int qcom_nandc_setup(struct qcom_nand_controller *nandc) >> { >> + u32 nand_ctrl; >> + >> /* kill onenand */ >> nandc_write(nandc, SFLASHC_BURST_CFG, 0); >> nandc_write(nandc, NAND_DEV_CMD_VLD, NAND_DEV_CMD_VLD_VAL); >> - /* enable ADM DMA */ >> - nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN); >> + /* enable ADM or BAM DMA */ >> + if (nandc->props->is_bam) { >> + nand_ctrl = nandc_read(nandc, NAND_CTRL); >> + nandc_write(nandc, NAND_CTRL, nand_ctrl | BAM_MODE_EN); >> + } else { >> + nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN); >> + } >> /* save the original values of these registers */ >> nandc->cmd1 = nandc_read(nandc, NAND_DEV_CMD1); >> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html