RE: [PATCH v3] mtd: rawnand: brcmnand: legacy exec_op implementation

William Zhang
2025-05-15T01:42:41Z

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Hi Alvaro,

> -----Original Message-----
> From: Álvaro Fernández Rojas <noltari@gmail.com>
> Sent: Tuesday, May 13, 2025 11:24 PM
> To: linux-mtd@lists.infradead.org; dregan@broadcom.com;
> miquel.raynal@bootlin.com; bcm-kernel-feedback-list@broadcom.com;
> florian.fainelli@broadcom.com; rafal@milecki.pl;
> computersforpeace@gmail.com; kamal.dasu@broadcom.com;
> dan.beygelman@broadcom.com; william.zhang@broadcom.com;
> frieder.schrempf@kontron.de; linux-kernel@vger.kernel.org;
> vigneshr@ti.com;
> richard@nod.at; bbrezillon@kernel.org; kdasu.kdev@gmail.com;
> jaimeliao.tw@gmail.com; kilobyte@angband.pl; jonas.gorski@gmail.com;
> dgcbueu@gmail.com
> Cc: Álvaro Fernández Rojas <noltari@gmail.com>
> Subject: [PATCH v3] mtd: rawnand: brcmnand: legacy exec_op implementation
>
> Commit 3c8260ce7663 ("mtd: rawnand: brcmnand: exec_op implementation")
> removed legacy interface functions, breaking < v5.0 controllers support.
> In order to fix older controllers we need to add an alternative exec_op
> implementation which doesn't rely on low level registers.
>
> Fixes: 3c8260ce7663 ("mtd: rawnand: brcmnand: exec_op implementation")
> Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
> ---
> drivers/mtd/nand/raw/brcmnand/brcmnand.c | 178
> ++++++++++++++++++++++-
> 1 file changed, 172 insertions(+), 6 deletions(-)
>
> v3: add changes requested by Florian and other improvements:
> - Add associative array for native command conversion.
> - Add function pointer to brcmnand_controller for exec_instr
> functionality.
> - Fix CMD_BLOCK_ERASE address.
> - Drop NAND_CMD_READOOB support.
>
> v2: multiple improvements:
> - Use proper native commands for checks.
> - Fix NAND_CMD_PARAM/NAND_CMD_RNDOUT addr calculation.
> - Remove host->last_addr usage.
> - Remove sector_size_1k since it only applies to v5.0+ controllers.
> - Remove brcmnand_wp since it doesn't exist for < v5.0 controllers.
> - Use j instead of i for flash_cache loop.
>
> diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> index 17f6d9723df9..f4fabe7ffd9d 100644
> --- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> +++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
> @@ -65,6 +65,7 @@ module_param(wp_on, int, 0444);
> #define CMD_PARAMETER_READ 0x0e
> #define CMD_PARAMETER_CHANGE_COL 0x0f
> #define CMD_LOW_LEVEL_OP 0x10
> +#define CMD_NOT_SUPPORTED 0xff
>
> struct brcm_nand_dma_desc {
> u32 next_desc;
> @@ -199,6 +200,30 @@ static const u16 flash_dma_regs_v4[] = {
> [FLASH_DMA_CURRENT_DESC_EXT] = 0x34,
> };
>
> +/* Native command conversion */
> +static const u8 native_cmd_conv[] = {
> + [NAND_CMD_READ0] = CMD_NOT_SUPPORTED,
> + [NAND_CMD_READ1] = CMD_NOT_SUPPORTED,
> + [NAND_CMD_RNDOUT] = CMD_PARAMETER_CHANGE_COL,
> + [NAND_CMD_PAGEPROG] = CMD_NOT_SUPPORTED,
> + [NAND_CMD_READOOB] = CMD_NOT_SUPPORTED,
> + [NAND_CMD_ERASE1] = CMD_BLOCK_ERASE,
> + [NAND_CMD_STATUS] = CMD_NOT_SUPPORTED,
Do we not need to support nand_status_op()?

> + [NAND_CMD_SEQIN] = CMD_NOT_SUPPORTED,
> + [NAND_CMD_RNDIN] = CMD_NOT_SUPPORTED,
> + [NAND_CMD_READID] = CMD_DEVICE_ID_READ,
> + [NAND_CMD_ERASE2] = CMD_NULL,
> + [NAND_CMD_PARAM] = CMD_PARAMETER_READ,
> + [NAND_CMD_GET_FEATURES] = CMD_NOT_SUPPORTED,
> + [NAND_CMD_SET_FEATURES] = CMD_NOT_SUPPORTED,
> + [NAND_CMD_RESET] = CMD_NOT_SUPPORTED,
> + [NAND_CMD_READSTART] = CMD_NOT_SUPPORTED,
> + [NAND_CMD_READCACHESEQ] = CMD_NOT_SUPPORTED,
> + [NAND_CMD_READCACHEEND] = CMD_NOT_SUPPORTED,
> + [NAND_CMD_RNDOUTSTART] = CMD_NULL,
> + [NAND_CMD_CACHEDPROG] = CMD_NOT_SUPPORTED,
> +};
> +
> /* Controller feature flags */
> enum {
> BRCMNAND_HAS_1K_SECTORS = BIT(0),
> @@ -237,6 +262,10 @@ struct brcmnand_controller {
> /* List of NAND hosts (one for each chip-select) */
> struct list_head host_list;
>
> + /* Function to be called from exec_op */
> + int (*exec_instr)(struct nand_chip *chip,
> + const struct nand_operation *op);
> +
> /* EDU info, per-transaction */
> const u16 *edu_offsets;
> void __iomem *edu_base;
> @@ -2490,14 +2519,149 @@ static int brcmnand_op_is_reset(const struct
> nand_operation *op)
> return 0;
> }
>
> +static int brcmnand_exec_instructions(struct nand_chip *chip,
> + const struct nand_operation *op)
> +{
> + struct brcmnand_host *host = nand_get_controller_data(chip);
> + unsigned int i;
> + int ret = 0;
> +
> + for (i = 0; i < op->ninstrs; i++) {
> + ret = brcmnand_exec_instr(host, i, op);
> + if (ret)
> + break;
> + }
> +
> + return ret;
> +}
> +
> +static int brcmnand_exec_instructions_legacy(struct nand_chip *chip,
> + const struct nand_operation *op)
> +{
> + struct mtd_info *mtd = nand_to_mtd(chip);
> + struct brcmnand_host *host = nand_get_controller_data(chip);
> + struct brcmnand_controller *ctrl = host->ctrl;
> + const struct nand_op_instr *instr;
> + unsigned int i, j;
> + u8 cmd = CMD_NULL, last_cmd = CMD_NULL;
> + int ret = 0;
> + u64 last_addr;
> +
> + for (i = 0; i < op->ninstrs; i++) {
> + instr = &op->instrs[i];
> +
> + if (instr->type == NAND_OP_CMD_INSTR) {
> + cmd = native_cmd_conv[instr->ctx.cmd.opcode];
> + if (cmd == CMD_NOT_SUPPORTED) {
> + dev_err(ctrl->dev, "unsupported cmd=%d\n",
> + instr->ctx.cmd.opcode);
> + ret = -EOPNOTSUPP;
> + break;
> + }
> + } else if (instr->type == NAND_OP_ADDR_INSTR) {
> + u64 addr = 0;
> +
> + if (cmd == CMD_NULL)
> + continue;
> +
> + if (instr->ctx.addr.naddrs > 8) {
> + dev_err(ctrl->dev, "unsupported naddrs=%u\n",
> + instr->ctx.addr.naddrs);
> + ret = -EOPNOTSUPP;
> + break;
> + }
> +
> + for (j = 0; j < instr->ctx.addr.naddrs; j++)
> + addr |= (instr->ctx.addr.addrs[j]) << (j << 3);
> +
> + if (cmd == CMD_BLOCK_ERASE)
> + addr <<= chip->page_shift;
> + else if (cmd == CMD_PARAMETER_CHANGE_COL)
> + addr &= ~((u64)(FC_BYTES - 1));
> +
> + brcmnand_set_cmd_addr(mtd, addr);
> + brcmnand_send_cmd(host, cmd);
> + last_addr = addr;
> + last_cmd = cmd;
> + cmd = CMD_NULL;
> + brcmnand_waitfunc(chip);
> +
> + if (last_cmd == CMD_PARAMETER_READ ||
> + last_cmd == CMD_PARAMETER_CHANGE_COL) {
> + /* Copy flash cache word-wise */
> + u32 *flash_cache = (u32 *)ctrl->flash_cache;
> +
> + brcmnand_soc_data_bus_prepare(ctrl->soc, true);
> +
> + /*
> + * Must cache the FLASH_CACHE now, since
> changes in
> + * SECTOR_SIZE_1K may invalidate it
> + */
> + for (j = 0; j < FC_WORDS; j++)
> + /*
> + * Flash cache is big endian for parameter
> pages, at
> + * least on STB SoCs
> + */
> + flash_cache[j] =
> be32_to_cpu(brcmnand_read_fc(ctrl, j));
> +
> + brcmnand_soc_data_bus_unprepare(ctrl->soc,
> true);
> + }
> + } else if (instr->type == NAND_OP_DATA_IN_INSTR) {
> + u8 *in = instr->ctx.data.buf.in;
> +
> + if (last_cmd == CMD_DEVICE_ID_READ) {
> + u32 val;
> +
> + if (instr->ctx.data.len > 8) {
> + dev_err(ctrl->dev, "unsupported
> len=%u\n",
> + instr->ctx.data.len);
> + ret = -EOPNOTSUPP;
> + break;
> + }
> +
> + for (j = 0; j < instr->ctx.data.len; j++) {
> + if (j == 0)
> + val = brcmnand_read_reg(ctrl,
> BRCMNAND_ID);
> + else if (j == 4)
> + val = brcmnand_read_reg(ctrl,
> BRCMNAND_ID_EXT);
> +
> + in[j] = (val >> (24 - ((j % 4) << 3))) & 0xff;
> + }
> + } else if (last_cmd == CMD_PARAMETER_READ ||
> + last_cmd == CMD_PARAMETER_CHANGE_COL) {
> + u64 addr;
> + u32 offs;
> +
> + for (j = 0; j < instr->ctx.data.len; j++) {
> + addr = last_addr + j;
> + offs = addr & (FC_BYTES - 1);
> +
> + if (j > 0 && offs == 0)
> +
> nand_change_read_column_op(chip, addr, NULL, 0,
> + false);
> +
> + in[j] = ctrl->flash_cache[offs];
> + }
> + }
> + } else if (instr->type == NAND_OP_WAITRDY_INSTR) {
> + ret = bcmnand_ctrl_poll_status(host, NAND_CTRL_RDY,
> NAND_CTRL_RDY, 0);
> + } else {
> + dev_err(ctrl->dev, "unsupported instruction type: %d\n",
> instr->type);
> + ret = -EINVAL;
> + }
> + }
> +
> + return ret;
> +}
> +
> static int brcmnand_exec_op(struct nand_chip *chip,
> const struct nand_operation *op,
> bool check_only)
> {
> struct brcmnand_host *host = nand_get_controller_data(chip);
> + struct brcmnand_controller *ctrl = host->ctrl;
> struct mtd_info *mtd = nand_to_mtd(chip);
> u8 *status;
> - unsigned int i;
> int ret = 0;
>
> if (check_only)
> @@ -2525,11 +2689,7 @@ static int brcmnand_exec_op(struct nand_chip *chip,
> if (op->deassert_wp)
> brcmnand_wp(mtd, 0);
>
> - for (i = 0; i < op->ninstrs; i++) {
> - ret = brcmnand_exec_instr(host, i, op);
> - if (ret)
> - break;
> - }
> + ctrl->exec_instr(chip, op);
>
> if (op->deassert_wp)
> brcmnand_wp(mtd, 1);
> @@ -3142,6 +3302,12 @@ int brcmnand_probe(struct platform_device *pdev,
> struct brcmnand_soc *soc)
> if (ret)
> goto err;
>
> + /* Only v5.0+ controllers have low level ops support */
> + if (ctrl->nand_version >= 0x0500)
> + ctrl->exec_instr = brcmnand_exec_instructions;
> + else
> + ctrl->exec_instr = brcmnand_exec_instructions_legacy;
> +
> /*
> * Most chips have this cache at a fixed offset within 'nand' block.
> * Some must specify this region separately.
> --
> 2.39.5

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