On Thu, 7 May 2020 13:00:33 +0200
Miquel Raynal <miquel.raynal@xxxxxxxxxxx> wrote:
> +/**
> + * struct arasan_nfc - Defines the Arasan NAND flash controller driver instance
> + * @dev: Pointer to the device structure
> + * @base: Remapped register area
> + * @controller_clk: Pointer to the system clock
> + * @bus_clk: Pointer to the flash clock
> + * @controller: Base controller structure
> + * @chips: List of all NAND chips attached to the controller
> + * @assigned_cs: Bitmask describing already assigned CS lines
> + * @cur_clk: Current clock rate
> + * @bf: Array of bitflips read in each ECC step
> + */
> +struct arasan_nfc {
> + struct device *dev;
> + void __iomem *base;
> + struct clk *controller_clk;
> + struct clk *bus_clk;
> + struct nand_controller controller;
> + struct list_head chips;
> + unsigned long assigned_cs;
> + unsigned int cur_clk;
> + u8 *bf;
Looks like this field is never used.
> +};
> +
> +static struct anand *to_anand(struct nand_chip *nand)
> +{
> + return container_of(nand, struct anand, chip);
> +}
> +
> +static struct arasan_nfc *to_anfc(struct nand_controller *ctrl)
> +{
> + return container_of(ctrl, struct arasan_nfc, controller);
> +}
> +
> +static void anfc_disable_int(struct arasan_nfc *nfc, u32 mask)
> +{
> + mask &= ~EVENT_MASK;
> + mask &= EVENT_MASK;
> + writel_relaxed(mask, nfc->base + INTR_SIG_EN_REG);
> +}
> +
> +static int anfc_wait_for_event(struct arasan_nfc *nfc, unsigned int event)
> +{
> + u32 val;
> + int ret;
> +
> + ret = readl_relaxed_poll_timeout(nfc->base + INTR_STS_REG, val,
> + val & event, 0,
> + ANFC_DFLT_TIMEOUT_US);
> + if (ret) {
> + dev_err(nfc->dev, "Timeout waiting for event 0x%x\n", event);
> + return -ETIMEDOUT;
> + }
> +
> + writel_relaxed(event, nfc->base + INTR_STS_REG);
> +
> + return 0;
> +}
> +
> +static int anfc_wait_for_rb(struct arasan_nfc *nfc, struct nand_chip *chip,
> + unsigned int timeout_ms)
> +{
> + struct anand *anand = to_anand(chip);
> + u32 val;
> + int ret;
> +
> + ret = readl_relaxed_poll_timeout(nfc->base + READY_STS_REG, val,
> + val & BIT(anand->rb),
> + 0, timeout_ms * 1000);
You don't have an interrupt on R/B transition? If can, that would
probably be better to use interrupts than polling the status reg.
> + if (ret) {
> + dev_err(nfc->dev, "Timeout waiting for R/B 0x%x\n",
> + readl_relaxed(nfc->base + READY_STS_REG));
> + return -ETIMEDOUT;
> + }
> +
> + return 0;
> +}
> +
> +static void anfc_trigger_op(struct arasan_nfc *nfc, struct anfc_op *nfc_op)
> +{
> + writel_relaxed(nfc_op->pkt_reg, nfc->base + PKT_REG);
> + writel_relaxed(nfc_op->addr1_reg, nfc->base + MEM_ADDR1_REG);
> + writel_relaxed(nfc_op->addr2_reg, nfc->base + MEM_ADDR2_REG);
> + writel_relaxed(nfc_op->cmd_reg, nfc->base + CMD_REG);
> + writel_relaxed(nfc_op->prog_reg, nfc->base + PROG_REG);
> +}
> +
> +static int anfc_len_to_steps(struct nand_chip *chip, unsigned int len)
> +{
> + unsigned int steps = 1, pktsize = len;
> +
> + while (pktsize > ANFC_MAX_PKT_SIZE) {
> + steps *= 2;
> + pktsize = DIV_ROUND_UP(len, steps);
Hm, I'm not sure that's right. What happens if steps * pksize is bigger
than the requested number of DATA cycles? Not all operations accept to
have more data read/written than requested.
I'd rather have something that does:
static void anfc_len_to_steps(struct nand_chip *chip, unsigned int len,
unsigned int *pktsize,
unsigned int *npkts)
{
if (len <= ANFC_MAX_PKT_SIZE) {
*pktsize = len;
*npkts = 1;
return;
}
for (*npkts = 2; *npkts < ANFC_MAX_NUM_PKTS; *npkts *= 2) {
*pktsize = len / *npkts;
if (*pktsize <= ANFC_MAX_PKT_SIZE)
break;
}
}
And then, from the call size, you trigger new DATA_OUT/IN operation if
len > pktsize * npkts.
> + }
> +
> + return steps;
I guess you have a limit on steps. It's probably worth checking
that steps is in bounds.
> +}
> +
> +/* NAND framework ->exec_op() hooks and related helpers */
> +static void anfc_parse_instructions(struct nand_chip *chip,
> + const struct nand_subop *subop,
> + struct anfc_op *nfc_op)
> +{
> + struct anand *anand = to_anand(chip);
> + const struct nand_op_instr *instr = NULL;
> + bool first_cmd = true;
> + unsigned int op_id;
> + int i;
> +
> + memset(nfc_op, 0, sizeof(*nfc_op));
> + nfc_op->addr2_reg = ADDR2_CS(anand->cs);
> + nfc_op->cmd_reg = CMD_PAGE_SIZE(anand->page_sz);
> +
> + for (op_id = 0; op_id < subop->ninstrs; op_id++) {
> + unsigned int offset, naddrs, pktsize;
> + const u8 *addrs;
> + u8 *buf;
> +
> + instr = &subop->instrs[op_id];
> +
> + switch (instr->type) {
> + case NAND_OP_CMD_INSTR:
> + if (first_cmd)
> + nfc_op->cmd_reg |= CMD_1(instr->ctx.cmd.opcode);
> + else
> + nfc_op->cmd_reg |= CMD_2(instr->ctx.cmd.opcode);
> +
> + first_cmd = false;
> + break;
> +
> + case NAND_OP_ADDR_INSTR:
> + offset = nand_subop_get_addr_start_off(subop, op_id);
> + naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
> + addrs = &instr->ctx.addr.addrs[offset];
> + nfc_op->cmd_reg |= CMD_NADDRS(naddrs);
> +
> + for (i = 0; i < min(ANFC_MAX_ADDR_CYC, naddrs); i++) {
> + if (i < 4)
> + nfc_op->addr1_reg |= (u32)addrs[i] << i * 8;
> + else
> + nfc_op->addr2_reg |= addrs[i];
> + }
> +
> + break;
> + case NAND_OP_DATA_IN_INSTR:
> + nfc_op->read = true;
> + fallthrough;
> + case NAND_OP_DATA_OUT_INSTR:
> + offset = nand_subop_get_data_start_off(subop, op_id);
> + buf = instr->ctx.data.buf.in;
> + nfc_op->buf = &buf[offset];
> + nfc_op->len = nand_subop_get_data_len(subop, op_id);
> + nfc_op->steps = anfc_len_to_steps(chip, nfc_op->len);
> + pktsize = DIV_ROUND_UP(nfc_op->len, nfc_op->steps);
> + nfc_op->pkt_reg |= PKT_SIZE(round_up(pktsize, 4)) |
Hm, pktsize has to be aligned on 4? Again, that's not great since you
adjust the size without letting the core know you did that.
> + PKT_STEPS(nfc_op->steps);
> + break;
> + case NAND_OP_WAITRDY_INSTR:
> + nfc_op->rdy_timeout_ms = instr->ctx.waitrdy.timeout_ms;
> + break;
> + }
> + }
> +}
> +
> +static int anfc_rw_pio_op(struct arasan_nfc *nfc, struct anfc_op *nfc_op)
> +{
> + unsigned int dwords = (nfc_op->len / 4) / nfc_op->steps;
> + unsigned int last_len = nfc_op->len % 4;
> + unsigned int offset, dir;
> + u8 *buf = nfc_op->buf;
> + int ret, i;
> +
> + for (i = 0; i < nfc_op->steps; i++) {
> + dir = nfc_op->read ? READ_READY : WRITE_READY;
> + ret = anfc_wait_for_event(nfc, dir);
> + if (ret) {
> + dev_err(nfc->dev, "PIO %s ready signal not received\n",
> + nfc_op->read ? "Read" : "Write");
> + return ret;
> + }
> +
> + offset = i * (dwords * 4);
> + if (nfc_op->read)
> + ioread32_rep(nfc->base + DATA_PORT_REG, &buf[offset],
> + dwords);
> + else
> + iowrite32_rep(nfc->base + DATA_PORT_REG, &buf[offset],
> + dwords);
> + }
> +
> + if (last_len) {
> + u32 remainder;
> +
> + offset = nfc_op->len - last_len;
> +
> + if (nfc_op->read) {
> + remainder = readl_relaxed(nfc->base + DATA_PORT_REG);
> + memcpy(&buf[offset], &remainder, last_len);
> + } else {
> + memcpy(&remainder, &buf[offset], last_len);
> + writel_relaxed(remainder, nfc->base + DATA_PORT_REG);
> + }
> + }
> +
> + return anfc_wait_for_event(nfc, XFER_COMPLETE);
> +}
> +
> +static int anfc_misc_data_type_exec(struct nand_chip *chip,
> + const struct nand_subop *subop,
> + u32 prog_reg)
> +{
> + struct arasan_nfc *nfc = to_anfc(chip->controller);
> + struct anfc_op nfc_op = {};
> + int ret;
> +
> + anfc_parse_instructions(chip, subop, &nfc_op);
> + nfc_op.prog_reg = prog_reg;
> + anfc_trigger_op(nfc, &nfc_op);
> +
> + if (nfc_op.rdy_timeout_ms) {
> + ret = anfc_wait_for_rb(nfc, chip, nfc_op.rdy_timeout_ms);
> + if (ret)
> + return ret;
> + }
> +
> + return anfc_rw_pio_op(nfc, &nfc_op);
> +}
> +
> +static int anfc_param_read_type_exec(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + return anfc_misc_data_type_exec(chip, subop, PROG_RDPARAM);
> +}
> +
> +static int anfc_data_read_type_exec(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + return anfc_misc_data_type_exec(chip, subop, PROG_PGRD);
> +}
> +
> +static int anfc_param_write_type_exec(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + return anfc_misc_data_type_exec(chip, subop, PROG_SET_FEATURE);
> +}
> +
> +static int anfc_data_write_type_exec(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + return anfc_misc_data_type_exec(chip, subop, PROG_PGPROG);
> +}
> +
> +static int anfc_misc_zerolen_type_exec(struct nand_chip *chip,
> + const struct nand_subop *subop,
> + u32 prog_reg)
> +{
> + struct arasan_nfc *nfc = to_anfc(chip->controller);
> + struct anfc_op nfc_op = {};
> + int ret;
> +
> + anfc_parse_instructions(chip, subop, &nfc_op);
> + nfc_op.prog_reg = prog_reg;
> + anfc_trigger_op(nfc, &nfc_op);
> +
> + ret = anfc_wait_for_event(nfc, XFER_COMPLETE);
> + if (ret)
> + return ret;
> +
> + if (nfc_op.rdy_timeout_ms)
> + ret = anfc_wait_for_rb(nfc, chip, nfc_op.rdy_timeout_ms);
> +
> + return ret;
> +}
> +
> +static int anfc_status_type_exec(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + struct arasan_nfc *nfc = to_anfc(chip->controller);
> + u32 tmp;
> + int ret;
> +
> + /*
> + * This controller does not allow to proceed with a CMD+DATA_IN cycle
> + * manually on the bus by reading data from the data register. Instead,
> + * the controller abstract the status read operation with its own status
> + * register after ordering a read status operation. Hence, the following
> + * hack.
> + */
> + if (subop->instrs[0].ctx.cmd.opcode != NAND_CMD_STATUS)
> + return -ENOTSUPP;
> +
> + ret = anfc_misc_zerolen_type_exec(chip, subop, PROG_STATUS);
> + if (ret)
> + return ret;
> +
> + tmp = readl_relaxed(nfc->base + FLASH_STS_REG);
> + memcpy(subop->instrs[1].ctx.data.buf.in, &tmp, 1);
> +
> + return 0;
> +}
> +
> +static int anfc_reset_type_exec(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + return anfc_misc_zerolen_type_exec(chip, subop, PROG_RST);
> +}
> +
> +static int anfc_erase_type_exec(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + return anfc_misc_zerolen_type_exec(chip, subop, PROG_ERASE);
> +}
> +
> +static int anfc_wait_type_exec(struct nand_chip *chip,
> + const struct nand_subop *subop)
> +{
> + struct arasan_nfc *nfc = to_anfc(chip->controller);
> + struct anfc_op nfc_op = {};
> +
> + anfc_parse_instructions(chip, subop, &nfc_op);
> +
> + return anfc_wait_for_rb(nfc, chip, nfc_op.rdy_timeout_ms);
> +}
> +
> +static const struct nand_op_parser anfc_op_parser = NAND_OP_PARSER(
> + NAND_OP_PARSER_PATTERN(
> + anfc_param_read_type_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_ADDR_ELEM(false, ANFC_MAX_ADDR_CYC),
> + NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
> + NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, ANFC_MAX_CHUNK_SIZE)),
> + NAND_OP_PARSER_PATTERN(
> + anfc_param_write_type_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_ADDR_ELEM(false, ANFC_MAX_ADDR_CYC),
> + NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, ANFC_MAX_PARAM_SIZE)),
> + NAND_OP_PARSER_PATTERN(
> + anfc_data_read_type_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_ADDR_ELEM(false, ANFC_MAX_ADDR_CYC),
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
> + NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, ANFC_MAX_CHUNK_SIZE)),
> + NAND_OP_PARSER_PATTERN(
> + anfc_data_write_type_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_ADDR_ELEM(false, ANFC_MAX_ADDR_CYC),
> + NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, ANFC_MAX_CHUNK_SIZE),
> + NAND_OP_PARSER_PAT_CMD_ELEM(false)),
> + NAND_OP_PARSER_PATTERN(
> + anfc_reset_type_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
> + NAND_OP_PARSER_PATTERN(
> + anfc_erase_type_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_ADDR_ELEM(false, ANFC_MAX_ADDR_CYC),
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
> + NAND_OP_PARSER_PATTERN(
> + anfc_status_type_exec,
> + NAND_OP_PARSER_PAT_CMD_ELEM(false),
> + NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, ANFC_MAX_CHUNK_SIZE)),
> + NAND_OP_PARSER_PATTERN(
> + anfc_wait_type_exec,
> + NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
> + );
> +
Okay, no DATA-only patterns, so my suggestion to split non-aligned data
reads doesn't work. I'd suggest to describe data-lengths
constraints rather than automatically adjusting the data length to
something bigger when we can't do exactly the number of requested DATA
cycles. I started doing something similar here [1], except you'd need
much more fined-grained constraints, so maybe we should add an optional
check hook to data patterns.
> +static int anfc_select_target(struct nand_chip *chip, int target)
> +{
> + struct anand *anand = to_anand(chip);
> + struct arasan_nfc *nfc = to_anfc(chip->controller);
> + int ret;
> +
> + /* Update the controller timings and the potential ECC configuration */
> + writel_relaxed(anand->timings, nfc->base + DATA_INTERFACE_REG);
> +
> + /* Update clock frequency */
> + if (nfc->cur_clk != anand->clk) {
> + clk_disable_unprepare(nfc->controller_clk);
> + ret = clk_set_rate(nfc->controller_clk, anand->clk);
> + if (ret) {
> + dev_err(nfc->dev, "Failed to change clock rate\n");
> + return ret;
> + }
> +
> + ret = clk_prepare_enable(nfc->controller_clk);
> + if (ret) {
> + dev_err(nfc->dev,
> + "Failed to re-enable the controller clock\n");
> + return ret;
> + }
> +
> + nfc->cur_clk = anand->clk;
> + }
> +
> + return 0;
> +}
> +
> +static int anfc_exec_op(struct nand_chip *chip,
> + const struct nand_operation *op,
> + bool check_only)
> +{
> + int ret;
> +
> + if (!check_only) {
> + ret = anfc_select_target(chip, op->cs);
> + if (ret)
> + return ret;
> + }
Given you do only one thing in the check_only case, I'd do:
if (check_only)
nand_op_parser_exec_op(chip, &anfc_op_parser, op, true);
ret = anfc_select_target(chip, op->cs);
if (ret)
return ret;
...
> +
> + return nand_op_parser_exec_op(chip, &anfc_op_parser, op, check_only);
> +}
> +
> +static int anfc_setup_data_interface(struct nand_chip *chip, int target,
> + const struct nand_data_interface *conf)
> +{
> + struct anand *anand = to_anand(chip);
> + struct arasan_nfc *nfc = to_anfc(chip->controller);
> + struct device_node *np = nfc->dev->of_node;
> +
> + if (target < 0)
> + return 0;
> +
> + anand->timings = DIFACE_SDR | DIFACE_SDR_MODE(conf->timings.mode);
> + anand->clk = ANFC_XLNX_SDR_DFLT_CORE_CLK;
> +
> + /*
> + * Due to a hardware bug in the ZynqMP SoC, SDR timing modes 0-1 work
> + * with f > 90MHz (default clock is 100MHz) but signals are unstable
> + * with higher modes. Hence we decrease a little bit the clock rate to
> + * 80MHz when using modes 2-5 with this SoC.
> + */
> + if (of_device_is_compatible(np, "xlnx,zynqmp-nand-controller") &&
> + conf->timings.mode >= 2)
> + anand->clk = ANFC_XLNX_SDR_HS_CORE_CLK;
> +
> + return 0;
> +}
> +
> +static int anfc_attach_chip(struct nand_chip *chip)
> +{
> + struct anand *anand = to_anand(chip);
> + struct arasan_nfc *nfc = to_anfc(chip->controller);
> + struct mtd_info *mtd = nand_to_mtd(chip);
> + int ret = 0;
> +
> + if (mtd->writesize <= SZ_512)
> + anand->caddr_cycles = 1;
> + else
> + anand->caddr_cycles = 2;
> +
> + if (chip->options & NAND_ROW_ADDR_3)
> + anand->raddr_cycles = 3;
> + else
> + anand->raddr_cycles = 2;
> +
> + switch (mtd->writesize) {
> + case 512:
> + anand->page_sz = 0;
> + break;
> + case 1024:
> + anand->page_sz = 5;
> + break;
> + case 2048:
> + anand->page_sz = 1;
> + break;
> + case 4096:
> + anand->page_sz = 2;
> + break;
> + case 8192:
> + anand->page_sz = 3;
> + break;
> + case 16384:
> + anand->page_sz = 4;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + /* These hooks are valid for all ECC providers */
> + chip->ecc.read_page_raw = nand_monolithic_read_page_raw;
> + chip->ecc.write_page_raw = nand_monolithic_write_page_raw;
> +
> + switch (chip->ecc.mode) {
> + case NAND_ECC_NONE:
> + case NAND_ECC_SOFT:
> + case NAND_ECC_ON_DIE:
> + break;
> + case NAND_ECC_HW:
> + default:
> + dev_err(nfc->dev, "Unsupported ECC mode: %d\n",
> + chip->ecc.mode);
> + return -EINVAL;
> + }
> +
> + return ret;
> +}
> +
> +static const struct nand_controller_ops anfc_ops = {
> + .exec_op = anfc_exec_op,
> + .setup_data_interface = anfc_setup_data_interface,
> + .attach_chip = anfc_attach_chip,
> +};
> +
> +static int anfc_chip_init(struct arasan_nfc *nfc, struct device_node *np)
> +{
> + struct anand *anand;
> + struct nand_chip *chip;
> + struct mtd_info *mtd;
> + int cs, rb, ret;
> +
> + anand = devm_kzalloc(nfc->dev, sizeof(*anand), GFP_KERNEL);
> + if (!anand)
> + return -ENOMEM;
> +
> + /* Only one CS can be asserted at a time */
You mean the controller only has one CS? Cause that comment doesn't
make much sense.
> + if (of_property_count_elems_of_size(np, "reg", sizeof(u32)) != 1) {
> + dev_err(nfc->dev, "Invalid reg property\n");
> + return -EINVAL;
> + }
It's only a SW limitation. If your controller has several CS pins
(which seems to be the case since you have a list of chips), it can
handle multi-CS chips too. I'm perfectly fine with the limitation
itself, but the comment should reflect the reality. And if you want to
support multi-CS chips, you just have to define an array of CS/RB in
anand.
> +
> + ret = of_property_read_u32(np, "reg", &cs);
> + if (ret)
> + return ret;
> +
> + ret = of_property_read_u32(np, "nand-rb", &rb);
> + if (ret)
> + return ret;
> +
> + if (cs >= ANFC_MAX_CS || rb >= ANFC_MAX_CS) {
> + dev_err(nfc->dev, "Wrong CS %d or RB %d\n", cs, rb);
> + return -EINVAL;
> + }
> +
> + if (test_and_set_bit(cs, &nfc->assigned_cs)) {
> + dev_err(nfc->dev, "Already assigned CS %d\n", cs);
> + return -EINVAL;
> + }
> +
> + anand->cs = cs;
> + anand->rb = rb;
> +
> + chip = &anand->chip;
> + mtd = nand_to_mtd(chip);
> + mtd->dev.parent = nfc->dev;
> + chip->controller = &nfc->controller;
> + chip->options = NAND_BUSWIDTH_AUTO | NAND_NO_SUBPAGE_WRITE |
> + NAND_USES_DMA;
> +
> + nand_set_flash_node(chip, np);
> + if (!mtd->name) {
> + dev_err(nfc->dev, "NAND label property is mandatory\n");
> + return -EINVAL;
> + }
> +
> + ret = nand_scan(chip, 1);
> + if (ret) {
> + dev_err(nfc->dev, "Scan operation failed\n");
> + return ret;
> + }
> +
> + ret = mtd_device_register(mtd, NULL, 0);
> + if (ret) {
> + nand_release(chip);
nand_cleanup(chip);
> + return ret;
> + }
> +
> + list_add_tail(&anand->node, &nfc->chips);
> +
> + return 0;
> +}
> +
> +static void anfc_chips_cleanup(struct arasan_nfc *nfc)
> +{
> + struct anand *anand, *tmp;
> +
> + list_for_each_entry_safe(anand, tmp, &nfc->chips, node) {
> + nand_release(&anand->chip);
> + list_del(&anand->node);
> + }
> +}
> +
> +static int anfc_chips_init(struct arasan_nfc *nfc)
> +{
> + struct device_node *np = nfc->dev->of_node, *nand_np;
> + int nchips = of_get_child_count(np);
> + int ret;
> +
> + if (!nchips || nchips > ANFC_MAX_CS) {
> + dev_err(nfc->dev, "Incorrect number of NAND chips (%d)\n",
> + nchips);
> + return -EINVAL;
> + }
> +
> + for_each_child_of_node(np, nand_np) {
> + ret = anfc_chip_init(nfc, nand_np);
> + if (ret) {
> + of_node_put(nand_np);
> + anfc_chips_cleanup(nfc);
> + break;
> + }
> + }
> +
> + return ret;
> +}
> +
> +static void anfc_reset(struct arasan_nfc *nfc)
> +{
> + anfc_disable_int(nfc, EVENT_MASK);
> +
> + /* Enable all interrupt status */
> + writel_relaxed(EVENT_MASK, nfc->base + INTR_STS_EN_REG);
That doesn't sounds like a good idea. Interrupts should be enabled only
when you need to wait on specific events.
> +}
> +
[1]https://github.com/bbrezillon/linux/commit/02c0ce63be2d43f207bdecafd555c42efdacece2
