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spi: intel: Add support for second flash chip
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Intel SPI flash controller has been supporting two chip selects long
time already even if the most common configuration is to have a single
flash chip for the BIOS and related data. This adds support for the
second chip select if we find out that there are two flash components
(this information is available in the mandatory flash descriptor on the
first chip). The second chip is exposed as is without any partition
information.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/r/20220816130818.89600-1-mika.westerberg@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
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Mika Westerberg authored and Mark Brown committed Aug 22, 2022
1 parent 51e99de commit 3f03c61
Showing 1 changed file with 147 additions and 16 deletions.
163 changes: 147 additions & 16 deletions drivers/spi/spi-intel.c
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Original file line number Diff line number Diff line change
Expand Up @@ -116,6 +116,22 @@
#define ERASE_64K_OPCODE_SHIFT 16
#define ERASE_64K_OPCODE_MASK (0xff << ERASE_OPCODE_SHIFT)

/* Flash descriptor fields */
#define FLVALSIG_MAGIC 0x0ff0a55a
#define FLMAP0_NC_MASK GENMASK(9, 8)
#define FLMAP0_NC_SHIFT 8
#define FLMAP0_FCBA_MASK GENMASK(7, 0)

#define FLCOMP_C0DEN_MASK GENMASK(3, 0)
#define FLCOMP_C0DEN_512K 0x00
#define FLCOMP_C0DEN_1M 0x01
#define FLCOMP_C0DEN_2M 0x02
#define FLCOMP_C0DEN_4M 0x03
#define FLCOMP_C0DEN_8M 0x04
#define FLCOMP_C0DEN_16M 0x05
#define FLCOMP_C0DEN_32M 0x06
#define FLCOMP_C0DEN_64M 0x07

#define INTEL_SPI_TIMEOUT 5000 /* ms */
#define INTEL_SPI_FIFO_SZ 64

Expand All @@ -129,6 +145,7 @@
* @master: Pointer to the SPI controller structure
* @nregions: Maximum number of regions
* @pr_num: Maximum number of protected range registers
* @chip0_size: Size of the first flash chip in bytes
* @locked: Is SPI setting locked
* @swseq_reg: Use SW sequencer in register reads/writes
* @swseq_erase: Use SW sequencer in erase operation
Expand All @@ -146,6 +163,7 @@ struct intel_spi {
struct spi_controller *master;
size_t nregions;
size_t pr_num;
size_t chip0_size;
bool locked;
bool swseq_reg;
bool swseq_erase;
Expand All @@ -158,6 +176,7 @@ struct intel_spi_mem_op {
struct spi_mem_op mem_op;
u32 replacement_op;
int (*exec_op)(struct intel_spi *ispi,
const struct spi_mem *mem,
const struct intel_spi_mem_op *iop,
const struct spi_mem_op *op);
};
Expand Down Expand Up @@ -441,16 +460,24 @@ static int intel_spi_sw_cycle(struct intel_spi *ispi, u8 opcode, size_t len,
return 0;
}

static int intel_spi_read_reg(struct intel_spi *ispi,
static u32 intel_spi_chip_addr(const struct intel_spi *ispi,
const struct spi_mem *mem)
{
/* Pick up the correct start address */
if (!mem)
return 0;
return mem->spi->chip_select == 1 ? ispi->chip0_size : 0;
}

static int intel_spi_read_reg(struct intel_spi *ispi, const struct spi_mem *mem,
const struct intel_spi_mem_op *iop,
const struct spi_mem_op *op)
{
size_t nbytes = op->data.nbytes;
u8 opcode = op->cmd.opcode;
int ret;

/* Address of the first chip */
writel(0, ispi->base + FADDR);
writel(intel_spi_chip_addr(ispi, mem), ispi->base + FADDR);

if (ispi->swseq_reg)
ret = intel_spi_sw_cycle(ispi, opcode, nbytes,
Expand All @@ -464,7 +491,7 @@ static int intel_spi_read_reg(struct intel_spi *ispi,
return intel_spi_read_block(ispi, op->data.buf.in, nbytes);
}

static int intel_spi_write_reg(struct intel_spi *ispi,
static int intel_spi_write_reg(struct intel_spi *ispi, const struct spi_mem *mem,
const struct intel_spi_mem_op *iop,
const struct spi_mem_op *op)
{
Expand Down Expand Up @@ -511,7 +538,7 @@ static int intel_spi_write_reg(struct intel_spi *ispi,
if (opcode == SPINOR_OP_WRDI)
return 0;

writel(0, ispi->base + FADDR);
writel(intel_spi_chip_addr(ispi, mem), ispi->base + FADDR);

/* Write the value beforehand */
ret = intel_spi_write_block(ispi, op->data.buf.out, nbytes);
Expand All @@ -524,13 +551,13 @@ static int intel_spi_write_reg(struct intel_spi *ispi,
return intel_spi_hw_cycle(ispi, opcode, nbytes);
}

static int intel_spi_read(struct intel_spi *ispi,
static int intel_spi_read(struct intel_spi *ispi, const struct spi_mem *mem,
const struct intel_spi_mem_op *iop,
const struct spi_mem_op *op)
{
void *read_buf = op->data.buf.in;
u32 addr = intel_spi_chip_addr(ispi, mem) + op->addr.val;
size_t block_size, nbytes = op->data.nbytes;
u32 addr = op->addr.val;
void *read_buf = op->data.buf.in;
u32 val, status;
int ret;

Expand Down Expand Up @@ -585,13 +612,13 @@ static int intel_spi_read(struct intel_spi *ispi,
return 0;
}

static int intel_spi_write(struct intel_spi *ispi,
static int intel_spi_write(struct intel_spi *ispi, const struct spi_mem *mem,
const struct intel_spi_mem_op *iop,
const struct spi_mem_op *op)
{
u32 addr = intel_spi_chip_addr(ispi, mem) + op->addr.val;
size_t block_size, nbytes = op->data.nbytes;
const void *write_buf = op->data.buf.out;
u32 addr = op->addr.val;
u32 val, status;
int ret;

Expand Down Expand Up @@ -648,12 +675,12 @@ static int intel_spi_write(struct intel_spi *ispi,
return 0;
}

static int intel_spi_erase(struct intel_spi *ispi,
static int intel_spi_erase(struct intel_spi *ispi, const struct spi_mem *mem,
const struct intel_spi_mem_op *iop,
const struct spi_mem_op *op)
{
u32 addr = intel_spi_chip_addr(ispi, mem) + op->addr.val;
u8 opcode = op->cmd.opcode;
u32 addr = op->addr.val;
u32 val, status;
int ret;

Expand Down Expand Up @@ -765,7 +792,7 @@ static int intel_spi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *o
if (!iop)
return -EOPNOTSUPP;

return iop->exec_op(ispi, iop, op);
return iop->exec_op(ispi, mem, iop, op);
}

static const char *intel_spi_get_name(struct spi_mem *mem)
Expand Down Expand Up @@ -805,7 +832,7 @@ static ssize_t intel_spi_dirmap_read(struct spi_mem_dirmap_desc *desc, u64 offs,
op.data.nbytes = len;
op.data.buf.in = buf;

ret = iop->exec_op(ispi, iop, &op);
ret = iop->exec_op(ispi, desc->mem, iop, &op);
return ret ? ret : len;
}

Expand All @@ -821,7 +848,7 @@ static ssize_t intel_spi_dirmap_write(struct spi_mem_dirmap_desc *desc, u64 offs
op.data.nbytes = len;
op.data.buf.out = buf;

ret = iop->exec_op(ispi, iop, &op);
ret = iop->exec_op(ispi, desc->mem, iop, &op);
return ret ? ret : len;
}

Expand Down Expand Up @@ -1226,10 +1253,98 @@ static void intel_spi_fill_partition(struct intel_spi *ispi,
}
}

static int intel_spi_read_desc(struct intel_spi *ispi)
{
struct spi_mem_op op =
SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_READ, 0),
SPI_MEM_OP_ADDR(3, 0, 0),
SPI_MEM_OP_NO_DUMMY,
SPI_MEM_OP_DATA_IN(0, NULL, 0));
u32 buf[2], nc, fcba, flcomp;
ssize_t ret;

op.addr.val = 0x10;
op.data.buf.in = buf;
op.data.nbytes = sizeof(buf);

ret = intel_spi_read(ispi, NULL, NULL, &op);
if (ret) {
dev_warn(ispi->dev, "failed to read descriptor\n");
return ret;
}

dev_dbg(ispi->dev, "FLVALSIG=0x%08x\n", buf[0]);
dev_dbg(ispi->dev, "FLMAP0=0x%08x\n", buf[1]);

if (buf[0] != FLVALSIG_MAGIC) {
dev_warn(ispi->dev, "descriptor signature not valid\n");
return -ENODEV;
}

fcba = (buf[1] & FLMAP0_FCBA_MASK) << 4;
dev_dbg(ispi->dev, "FCBA=%#x\n", fcba);

op.addr.val = fcba;
op.data.buf.in = &flcomp;
op.data.nbytes = sizeof(flcomp);

ret = intel_spi_read(ispi, NULL, NULL, &op);
if (ret) {
dev_warn(ispi->dev, "failed to read FLCOMP\n");
return -ENODEV;
}

dev_dbg(ispi->dev, "FLCOMP=0x%08x\n", flcomp);

switch (flcomp & FLCOMP_C0DEN_MASK) {
case FLCOMP_C0DEN_512K:
ispi->chip0_size = SZ_512K;
break;
case FLCOMP_C0DEN_1M:
ispi->chip0_size = SZ_1M;
break;
case FLCOMP_C0DEN_2M:
ispi->chip0_size = SZ_2M;
break;
case FLCOMP_C0DEN_4M:
ispi->chip0_size = SZ_4M;
break;
case FLCOMP_C0DEN_8M:
ispi->chip0_size = SZ_8M;
break;
case FLCOMP_C0DEN_16M:
ispi->chip0_size = SZ_16M;
break;
case FLCOMP_C0DEN_32M:
ispi->chip0_size = SZ_32M;
break;
case FLCOMP_C0DEN_64M:
ispi->chip0_size = SZ_64M;
break;
default:
return -EINVAL;
}

dev_dbg(ispi->dev, "chip0 size %zd KB\n", ispi->chip0_size / SZ_1K);

nc = (buf[1] & FLMAP0_NC_MASK) >> FLMAP0_NC_SHIFT;
if (!nc)
ispi->master->num_chipselect = 1;
else if (nc == 1)
ispi->master->num_chipselect = 2;
else
return -EINVAL;

dev_dbg(ispi->dev, "%u flash components found\n",
ispi->master->num_chipselect);
return 0;
}

static int intel_spi_populate_chip(struct intel_spi *ispi)
{
struct flash_platform_data *pdata;
struct spi_board_info chip;
int ret;

pdata = devm_kzalloc(ispi->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
Expand All @@ -1247,7 +1362,23 @@ static int intel_spi_populate_chip(struct intel_spi *ispi)
snprintf(chip.modalias, 8, "spi-nor");
chip.platform_data = pdata;

return spi_new_device(ispi->master, &chip) ? 0 : -ENODEV;
if (!spi_new_device(ispi->master, &chip))
return -ENODEV;

/* Add the second chip if present */
if (ispi->master->num_chipselect < 2)
return 0;

ret = intel_spi_read_desc(ispi);
if (ret)
return ret;

chip.platform_data = NULL;
chip.chip_select = 1;

if (!spi_new_device(ispi->master, &chip))
return -ENODEV;
return 0;
}

/**
Expand Down

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