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From: Pratyush Yadav
To: Mark Brown ,
Vignesh Raghavendra
CC: Pratyush Yadav , ,
Subject: [PATCH 7/7] spi: cadence-quadspi: Add DTR support
Date: Wed, 23 Dec 2020 00:14:25 +0530
Message-ID: <20201222184425.7028-8-p.yadav@ti.com>
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Double Transfer Rate (DTR) mode transfers data twice per clock cycle.
Add support for parsing DTR ops and set up the registers to allow it.
Most SPI NOR flashes expect 2 byte commands. Parse the 2-byte opcode
from SPI MEM and set it up in the CQSPI_REG_OP_EXT_LOWER register.
Increment the delay needed before issuing indirect writes because larger
delay is needed for DTR mode. With the current delay some writes end up
missing.
Signed-off-by: Pratyush Yadav
---
drivers/spi/spi-cadence-quadspi.c | 281 +++++++++++++++++++++++++-----
1 file changed, 242 insertions(+), 39 deletions(-)
diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
index 90040664e1b9..06a65e9a8a60 100644
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -52,6 +52,7 @@ struct cqspi_flash_pdata {
u8 inst_width;
u8 addr_width;
u8 data_width;
+ bool dtr;
u8 cs;
};
@@ -111,6 +112,8 @@ struct cqspi_driver_platdata {
#define CQSPI_REG_CONFIG_CHIPSELECT_LSB 10
#define CQSPI_REG_CONFIG_DMA_MASK BIT(15)
#define CQSPI_REG_CONFIG_BAUD_LSB 19
+#define CQSPI_REG_CONFIG_DTR_PROTO BIT(24)
+#define CQSPI_REG_CONFIG_DUAL_OPCODE BIT(30)
#define CQSPI_REG_CONFIG_IDLE_LSB 31
#define CQSPI_REG_CONFIG_CHIPSELECT_MASK 0xF
#define CQSPI_REG_CONFIG_BAUD_MASK 0xF
@@ -173,6 +176,9 @@ struct cqspi_driver_platdata {
#define CQSPI_REG_SDRAMLEVEL_RD_MASK 0xFFFF
#define CQSPI_REG_SDRAMLEVEL_WR_MASK 0xFFFF
+#define CQSPI_REG_WR_COMPLETION_CTRL 0x38
+#define CQSPI_REG_WR_DISABLE_AUTO_POLL BIT(14)
+
#define CQSPI_REG_IRQSTATUS 0x40
#define CQSPI_REG_IRQMASK 0x44
@@ -216,6 +222,14 @@ struct cqspi_driver_platdata {
#define CQSPI_REG_CMDWRITEDATALOWER 0xA8
#define CQSPI_REG_CMDWRITEDATAUPPER 0xAC
+#define CQSPI_REG_POLLING_STATUS 0xB0
+#define CQSPI_REG_POLLING_STATUS_DUMMY_LSB 16
+
+#define CQSPI_REG_OP_EXT_LOWER 0xE0
+#define CQSPI_REG_OP_EXT_READ_LSB 24
+#define CQSPI_REG_OP_EXT_WRITE_LSB 16
+#define CQSPI_REG_OP_EXT_STIG_LSB 0
+
/* Interrupt status bits */
#define CQSPI_REG_IRQ_MODE_ERR BIT(0)
#define CQSPI_REG_IRQ_UNDERFLOW BIT(1)
@@ -290,15 +304,80 @@ static unsigned int cqspi_calc_rdreg(struct cqspi_flash_pdata *f_pdata)
return rdreg;
}
-static unsigned int cqspi_calc_dummy(const struct spi_mem_op *op)
+static unsigned int cqspi_calc_dummy(const struct spi_mem_op *op, bool dtr)
{
unsigned int dummy_clk;
dummy_clk = op->dummy.nbytes * (8 / op->dummy.buswidth);
+ if (dtr)
+ dummy_clk /= 2;
return dummy_clk;
}
+static int cqspi_set_protocol(struct cqspi_flash_pdata *f_pdata,
+ const struct spi_mem_op *op)
+{
+ f_pdata->inst_width = CQSPI_INST_TYPE_SINGLE;
+ f_pdata->addr_width = CQSPI_INST_TYPE_SINGLE;
+ f_pdata->data_width = CQSPI_INST_TYPE_SINGLE;
+ f_pdata->dtr = op->data.dtr && op->cmd.dtr && op->addr.dtr;
+
+ switch (op->data.buswidth) {
+ case 0:
+ break;
+ case 1:
+ f_pdata->data_width = CQSPI_INST_TYPE_SINGLE;
+ break;
+ case 2:
+ f_pdata->data_width = CQSPI_INST_TYPE_DUAL;
+ break;
+ case 4:
+ f_pdata->data_width = CQSPI_INST_TYPE_QUAD;
+ break;
+ case 8:
+ f_pdata->data_width = CQSPI_INST_TYPE_OCTAL;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Right now we only support 8-8-8 DTR mode. */
+ if (f_pdata->dtr) {
+ switch (op->cmd.buswidth) {
+ case 0:
+ break;
+ case 8:
+ f_pdata->inst_width = CQSPI_INST_TYPE_OCTAL;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ switch (op->addr.buswidth) {
+ case 0:
+ break;
+ case 8:
+ f_pdata->addr_width = CQSPI_INST_TYPE_OCTAL;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ switch (op->data.buswidth) {
+ case 0:
+ break;
+ case 8:
+ f_pdata->data_width = CQSPI_INST_TYPE_OCTAL;
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
static int cqspi_wait_idle(struct cqspi_st *cqspi)
{
const unsigned int poll_idle_retry = 3;
@@ -356,13 +435,69 @@ static int cqspi_exec_flash_cmd(struct cqspi_st *cqspi, unsigned int reg)
return cqspi_wait_idle(cqspi);
}
+static int cqspi_setup_opcode_ext(struct cqspi_flash_pdata *f_pdata,
+ const struct spi_mem_op *op,
+ unsigned int shift)
+{
+ struct cqspi_st *cqspi = f_pdata->cqspi;
+ void __iomem *reg_base = cqspi->iobase;
+ unsigned int reg;
+ u8 ext;
+
+ if (op->cmd.nbytes != 2)
+ return -EINVAL;
+
+ /* Opcode extension is the LSB. */
+ ext = op->cmd.opcode & 0xff;
+
+ reg = readl(reg_base + CQSPI_REG_OP_EXT_LOWER);
+ reg &= ~(0xff << shift);
+ reg |= ext << shift;
+ writel(reg, reg_base + CQSPI_REG_OP_EXT_LOWER);
+
+ return 0;
+}
+
+static int cqspi_enable_dtr(struct cqspi_flash_pdata *f_pdata,
+ const struct spi_mem_op *op, unsigned int shift,
+ bool enable)
+{
+ struct cqspi_st *cqspi = f_pdata->cqspi;
+ void __iomem *reg_base = cqspi->iobase;
+ unsigned int reg;
+ int ret;
+
+ reg = readl(reg_base + CQSPI_REG_CONFIG);
+
+ /*
+ * We enable dual byte opcode here. The callers have to set up the
+ * extension opcode based on which type of operation it is.
+ */
+ if (enable) {
+ reg |= CQSPI_REG_CONFIG_DTR_PROTO;
+ reg |= CQSPI_REG_CONFIG_DUAL_OPCODE;
+
+ /* Set up command opcode extension. */
+ ret = cqspi_setup_opcode_ext(f_pdata, op, shift);
+ if (ret)
+ return ret;
+ } else {
+ reg &= ~CQSPI_REG_CONFIG_DTR_PROTO;
+ reg &= ~CQSPI_REG_CONFIG_DUAL_OPCODE;
+ }
+
+ writel(reg, reg_base + CQSPI_REG_CONFIG);
+
+ return cqspi_wait_idle(cqspi);
+}
+
static int cqspi_command_read(struct cqspi_flash_pdata *f_pdata,
const struct spi_mem_op *op)
{
struct cqspi_st *cqspi = f_pdata->cqspi;
void __iomem *reg_base = cqspi->iobase;
u8 *rxbuf = op->data.buf.in;
- u8 opcode = op->cmd.opcode;
+ u8 opcode;
size_t n_rx = op->data.nbytes;
unsigned int rdreg;
unsigned int reg;
@@ -370,6 +505,15 @@ static int cqspi_command_read(struct cqspi_flash_pdata *f_pdata,
size_t read_len;
int status;
+ status = cqspi_set_protocol(f_pdata, op);
+ if (status)
+ return status;
+
+ status = cqspi_enable_dtr(f_pdata, op, CQSPI_REG_OP_EXT_STIG_LSB,
+ f_pdata->dtr);
+ if (status)
+ return status;
+
if (!n_rx || n_rx > CQSPI_STIG_DATA_LEN_MAX || !rxbuf) {
dev_err(&cqspi->pdev->dev,
"Invalid input argument, len %zu rxbuf 0x%p\n",
@@ -377,12 +521,17 @@ static int cqspi_command_read(struct cqspi_flash_pdata *f_pdata,
return -EINVAL;
}
+ if (f_pdata->dtr)
+ opcode = op->cmd.opcode >> 8;
+ else
+ opcode = op->cmd.opcode;
+
reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
rdreg = cqspi_calc_rdreg(f_pdata);
writel(rdreg, reg_base + CQSPI_REG_RD_INSTR);
- dummy_clk = cqspi_calc_dummy(op);
+ dummy_clk = cqspi_calc_dummy(op, f_pdata->dtr);
if (dummy_clk > CQSPI_DUMMY_CLKS_MAX)
return -EOPNOTSUPP;
@@ -421,12 +570,22 @@ static int cqspi_command_write(struct cqspi_flash_pdata *f_pdata,
{
struct cqspi_st *cqspi = f_pdata->cqspi;
void __iomem *reg_base = cqspi->iobase;
- const u8 opcode = op->cmd.opcode;
+ u8 opcode;
const u8 *txbuf = op->data.buf.out;
size_t n_tx = op->data.nbytes;
unsigned int reg;
unsigned int data;
size_t write_len;
+ int ret;
+
+ ret = cqspi_set_protocol(f_pdata, op);
+ if (ret)
+ return ret;
+
+ ret = cqspi_enable_dtr(f_pdata, op, CQSPI_REG_OP_EXT_STIG_LSB,
+ f_pdata->dtr);
+ if (ret)
+ return ret;
if (n_tx > CQSPI_STIG_DATA_LEN_MAX || (n_tx && !txbuf)) {
dev_err(&cqspi->pdev->dev,
@@ -435,6 +594,14 @@ static int cqspi_command_write(struct cqspi_flash_pdata *f_pdata,
return -EINVAL;
}
+ reg = cqspi_calc_rdreg(f_pdata);
+ writel(reg, reg_base + CQSPI_REG_RD_INSTR);
+
+ if (f_pdata->dtr)
+ opcode = op->cmd.opcode >> 8;
+ else
+ opcode = op->cmd.opcode;
+
reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
if (op->addr.nbytes) {
@@ -474,12 +641,24 @@ static int cqspi_read_setup(struct cqspi_flash_pdata *f_pdata,
void __iomem *reg_base = cqspi->iobase;
unsigned int dummy_clk = 0;
unsigned int reg;
+ int ret;
+ u8 opcode;
- reg = op->cmd.opcode << CQSPI_REG_RD_INSTR_OPCODE_LSB;
+ ret = cqspi_enable_dtr(f_pdata, op, CQSPI_REG_OP_EXT_READ_LSB,
+ f_pdata->dtr);
+ if (ret)
+ return ret;
+
+ if (f_pdata->dtr)
+ opcode = op->cmd.opcode >> 8;
+ else
+ opcode = op->cmd.opcode;
+
+ reg = opcode << CQSPI_REG_RD_INSTR_OPCODE_LSB;
reg |= cqspi_calc_rdreg(f_pdata);
/* Setup dummy clock cycles */
- dummy_clk = cqspi_calc_dummy(op);
+ dummy_clk = cqspi_calc_dummy(op, f_pdata->dtr);
if (dummy_clk > CQSPI_DUMMY_CLKS_MAX)
return -EOPNOTSUPP;
@@ -594,15 +773,43 @@ static int cqspi_write_setup(struct cqspi_flash_pdata *f_pdata,
const struct spi_mem_op *op)
{
unsigned int reg;
+ int ret;
struct cqspi_st *cqspi = f_pdata->cqspi;
void __iomem *reg_base = cqspi->iobase;
+ u8 opcode;
+
+ ret = cqspi_enable_dtr(f_pdata, op, CQSPI_REG_OP_EXT_WRITE_LSB,
+ f_pdata->dtr);
+ if (ret)
+ return ret;
+
+ if (f_pdata->dtr)
+ opcode = op->cmd.opcode >> 8;
+ else
+ opcode = op->cmd.opcode;
/* Set opcode. */
- reg = op->cmd.opcode << CQSPI_REG_WR_INSTR_OPCODE_LSB;
+ reg = opcode << CQSPI_REG_WR_INSTR_OPCODE_LSB;
+ reg |= f_pdata->data_width << CQSPI_REG_WR_INSTR_TYPE_DATA_LSB;
+ reg |= f_pdata->addr_width << CQSPI_REG_WR_INSTR_TYPE_ADDR_LSB;
writel(reg, reg_base + CQSPI_REG_WR_INSTR);
reg = cqspi_calc_rdreg(f_pdata);
writel(reg, reg_base + CQSPI_REG_RD_INSTR);
+ if (f_pdata->dtr) {
+ /*
+ * Some flashes like the cypress Semper flash expect a 4-byte
+ * dummy address with the Read SR command in DTR mode, but this
+ * controller does not support sending address with the Read SR
+ * command. So, disable write completion polling on the
+ * controller's side. spi-nor will take care of polling the
+ * status register.
+ */
+ reg = readl(reg_base + CQSPI_REG_WR_COMPLETION_CTRL);
+ reg |= CQSPI_REG_WR_DISABLE_AUTO_POLL;
+ writel(reg, reg_base + CQSPI_REG_WR_COMPLETION_CTRL);
+ }
+
reg = readl(reg_base + CQSPI_REG_SIZE);
reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
reg |= (op->addr.nbytes - 1);
@@ -856,35 +1063,6 @@ static void cqspi_configure(struct cqspi_flash_pdata *f_pdata,
cqspi_controller_enable(cqspi, 1);
}
-static int cqspi_set_protocol(struct cqspi_flash_pdata *f_pdata,
- const struct spi_mem_op *op)
-{
- f_pdata->inst_width = CQSPI_INST_TYPE_SINGLE;
- f_pdata->addr_width = CQSPI_INST_TYPE_SINGLE;
- f_pdata->data_width = CQSPI_INST_TYPE_SINGLE;
-
- if (op->data.dir == SPI_MEM_DATA_IN) {
- switch (op->data.buswidth) {
- case 1:
- f_pdata->data_width = CQSPI_INST_TYPE_SINGLE;
- break;
- case 2:
- f_pdata->data_width = CQSPI_INST_TYPE_DUAL;
- break;
- case 4:
- f_pdata->data_width = CQSPI_INST_TYPE_QUAD;
- break;
- case 8:
- f_pdata->data_width = CQSPI_INST_TYPE_OCTAL;
- break;
- default:
- return -EINVAL;
- }
- }
-
- return 0;
-}
-
static ssize_t cqspi_write(struct cqspi_flash_pdata *f_pdata,
const struct spi_mem_op *op)
{
@@ -902,7 +1080,16 @@ static ssize_t cqspi_write(struct cqspi_flash_pdata *f_pdata,
if (ret)
return ret;
- if (cqspi->use_direct_mode && ((to + len) <= cqspi->ahb_size)) {
+ /*
+ * Some flashes like the Cypress Semper flash expect a dummy 4-byte
+ * address (all 0s) with the read status register command in DTR mode.
+ * But this controller does not support sending dummy address bytes to
+ * the flash when it is polling the write completion register in DTR
+ * mode. So, we can not use direct mode when in DTR mode for writing
+ * data.
+ */
+ if (!f_pdata->dtr && cqspi->use_direct_mode &&
+ ((to + len) <= cqspi->ahb_size)) {
memcpy_toio(cqspi->ahb_base + to, buf, len);
return cqspi_wait_idle(cqspi);
}
@@ -1072,6 +1259,8 @@ static int cqspi_check_buswidth_req(struct spi_mem *mem, u8 buswidth, bool tx)
static bool cqspi_supports_mem_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
+ bool all_true, all_false;
+
if (cqspi_check_buswidth_req(mem, op->cmd.buswidth, true))
return false;
@@ -1088,6 +1277,19 @@ static bool cqspi_supports_mem_op(struct spi_mem *mem,
op->data.dir == SPI_MEM_DATA_OUT))
return false;
+ all_true = op->cmd.dtr && op->addr.dtr && op->dummy.dtr &&
+ op->data.dtr;
+ all_false = !op->cmd.dtr && !op->addr.dtr && !op->dummy.dtr &&
+ !op->data.dtr;
+
+ /* Mixed DTR modes not supported. */
+ if (!(all_true || all_false))
+ return false;
+
+ /* DTR mode opcodes should be 2 bytes. */
+ if (all_true && op->cmd.nbytes != 2)
+ return false;
+
return true;
}
@@ -1365,10 +1567,10 @@ static int cqspi_probe(struct platform_device *pdev)
ddata = of_device_get_match_data(dev);
if (ddata) {
if (ddata->quirks & CQSPI_NEEDS_WR_DELAY)
- cqspi->wr_delay = 5 * DIV_ROUND_UP(NSEC_PER_SEC,
+ cqspi->wr_delay = 50 * DIV_ROUND_UP(NSEC_PER_SEC,
cqspi->master_ref_clk_hz);
if (ddata->hwcaps_mask & CQSPI_SUPPORTS_OCTAL)
- master->mode_bits |= SPI_RX_OCTAL;
+ master->mode_bits |= SPI_RX_OCTAL | SPI_TX_OCTAL;
if (!(ddata->quirks & CQSPI_DISABLE_DAC_MODE))
cqspi->use_direct_mode = true;
}
@@ -1510,3 +1712,4 @@ MODULE_AUTHOR("Ley Foon Tan ");
MODULE_AUTHOR("Graham Moore ");
MODULE_AUTHOR("Vadivel Murugan R ");
MODULE_AUTHOR("Vignesh Raghavendra ");
+MODULE_AUTHOR("Pratyush Yadav ");