From 443440cc4a901af462239d286cd10721aa1c7dfc Mon Sep 17 00:00:00 2001 From: Sivaprakash Murugesan Date: Fri, 12 Jun 2020 13:28:15 +0530 Subject: mtd: rawnand: qcom: avoid write to unavailable register SFLASHC_BURST_CFG is only available on older ipq NAND platforms, this register has been removed when the NAND controller got implemented in the qpic controller. Avoid writing this register on devices which are based on qpic NAND controller. Fixes: dce84760b09f ("mtd: nand: qcom: Support for IPQ8074 QPIC NAND controller") Cc: stable@vger.kernel.org Signed-off-by: Sivaprakash Murugesan Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/1591948696-16015-2-git-send-email-sivaprak@codeaurora.org --- drivers/mtd/nand/raw/qcom_nandc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers/mtd/nand/raw/qcom_nandc.c') diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c index f1daf330951b..78b5f211598c 100644 --- a/drivers/mtd/nand/raw/qcom_nandc.c +++ b/drivers/mtd/nand/raw/qcom_nandc.c @@ -459,11 +459,13 @@ struct qcom_nand_host { * among different NAND controllers. * @ecc_modes - ecc mode for NAND * @is_bam - whether NAND controller is using BAM + * @is_qpic - whether NAND CTRL is part of qpic IP * @dev_cmd_reg_start - NAND_DEV_CMD_* registers starting offset */ struct qcom_nandc_props { u32 ecc_modes; bool is_bam; + bool is_qpic; u32 dev_cmd_reg_start; }; @@ -2774,7 +2776,8 @@ static int qcom_nandc_setup(struct qcom_nand_controller *nandc) u32 nand_ctrl; /* kill onenand */ - nandc_write(nandc, SFLASHC_BURST_CFG, 0); + if (!nandc->props->is_qpic) + nandc_write(nandc, SFLASHC_BURST_CFG, 0); nandc_write(nandc, dev_cmd_reg_addr(nandc, NAND_DEV_CMD_VLD), NAND_DEV_CMD_VLD_VAL); @@ -3035,12 +3038,14 @@ static const struct qcom_nandc_props ipq806x_nandc_props = { static const struct qcom_nandc_props ipq4019_nandc_props = { .ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT), .is_bam = true, + .is_qpic = true, .dev_cmd_reg_start = 0x0, }; static const struct qcom_nandc_props ipq8074_nandc_props = { .ecc_modes = (ECC_BCH_4BIT | ECC_BCH_8BIT), .is_bam = true, + .is_qpic = true, .dev_cmd_reg_start = 0x7000, }; -- cgit v1.2.3 From cb272395dceef1652247dad08a50ed4153ffbd43 Mon Sep 17 00:00:00 2001 From: Sivaprakash Murugesan Date: Fri, 12 Jun 2020 13:28:16 +0530 Subject: mtd: rawnand: qcom: set BAM mode only if not set already BAM is DMA controller on QCOM ipq platforms, BAM mode on NAND driver is set by writing BAM_MODE_EN bit on NAND_CTRL register. NAND_CTRL is an operational register and in BAM mode operational registers are read only. So, before enabling BAM mode by writing the NAND_CTRL register, check if BAM mode was already enabled by the bootloader, and enable BAM mode only if it is not enabled already. Signed-off-by: Sivaprakash Murugesan Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/1591948696-16015-3-git-send-email-sivaprak@codeaurora.org --- drivers/mtd/nand/raw/qcom_nandc.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'drivers/mtd/nand/raw/qcom_nandc.c') diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c index 78b5f211598c..bd7a7251429b 100644 --- a/drivers/mtd/nand/raw/qcom_nandc.c +++ b/drivers/mtd/nand/raw/qcom_nandc.c @@ -2784,7 +2784,16 @@ static int qcom_nandc_setup(struct qcom_nand_controller *nandc) /* 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); + + /* + *NAND_CTRL is an operational registers, and CPU + * access to operational registers are read only + * in BAM mode. So update the NAND_CTRL register + * only if it is not in BAM mode. In most cases BAM + * mode will be enabled in bootloader + */ + if (!(nand_ctrl & BAM_MODE_EN)) + nandc_write(nandc, NAND_CTRL, nand_ctrl | BAM_MODE_EN); } else { nandc_write(nandc, NAND_FLASH_CHIP_SELECT, DM_EN); } -- cgit v1.2.3