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From:   Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
To:     Mark Brown <broonie@kernel.org>
Cc:     Pratyush Yadav <p.yadav@ti.com>,
        Tudor Ambarus <tudor.ambarus@microchip.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Ramuthevar Vadivel Murugan 
        <vadivel.muruganx.ramuthevar@linux.intel.com>,
        linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org,
        Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Subject: [PATCH v2 1/2] spi: cadence-quadspi: drop cqspi_set_protocol()
Date:   Wed, 20 Apr 2022 17:56:15 +0200
Message-Id: <20220420155616.281730-1-matthias.schiffer@ew.tq-group.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

As suggested, this removes the whole cqspi_set_protocol() function, as it
is not actually needed:

- Checks for unsupported operations are already handled by supports_op(),
  removing the need to distinguish DTR and non-DTR modes in the buswidth
  setup
- supports_op() ensures that the DTR flags match for all relevant parts of
  an operation, so op->cmd.dtr can be used instead of copying the flag to
  the cqspi_flash_pdata
- The logic in cqspi_set_protocol() is moved to cqspi_calc_rdreg() and
  cqspi_write_setup() (with a helper macro CQSPI_OP_WIDTH())

The helper macro checks nbytes instead of buswidth for 0, for consistency
with supports_op() etc.

Suggested-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
---

v2: remove cqspi_set_protocol() instead of simplifying it


 drivers/spi/spi-cadence-quadspi.c | 130 +++++++-----------------------
 1 file changed, 27 insertions(+), 103 deletions(-)

diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
index 19686fb47bb3..8c12c6dd58ae 100644
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -43,6 +43,8 @@
 /* Capabilities */
 #define CQSPI_SUPPORTS_OCTAL		BIT(0)
 
+#define CQSPI_OP_WIDTH(part) ((part).nbytes ? ilog2((part).buswidth) : 0)
+
 struct cqspi_st;
 
 struct cqspi_flash_pdata {
@@ -53,10 +55,6 @@ struct cqspi_flash_pdata {
 	u32		tsd2d_ns;
 	u32		tchsh_ns;
 	u32		tslch_ns;
-	u8		inst_width;
-	u8		addr_width;
-	u8		data_width;
-	bool		dtr;
 	u8		cs;
 };
 
@@ -343,18 +341,18 @@ static irqreturn_t cqspi_irq_handler(int this_irq, void *dev)
 	return IRQ_HANDLED;
 }
 
-static unsigned int cqspi_calc_rdreg(struct cqspi_flash_pdata *f_pdata)
+static unsigned int cqspi_calc_rdreg(const struct spi_mem_op *op)
 {
 	u32 rdreg = 0;
 
-	rdreg |= f_pdata->inst_width << CQSPI_REG_RD_INSTR_TYPE_INSTR_LSB;
-	rdreg |= f_pdata->addr_width << CQSPI_REG_RD_INSTR_TYPE_ADDR_LSB;
-	rdreg |= f_pdata->data_width << CQSPI_REG_RD_INSTR_TYPE_DATA_LSB;
+	rdreg |= CQSPI_OP_WIDTH(op->cmd) << CQSPI_REG_RD_INSTR_TYPE_INSTR_LSB;
+	rdreg |= CQSPI_OP_WIDTH(op->addr) << CQSPI_REG_RD_INSTR_TYPE_ADDR_LSB;
+	rdreg |= CQSPI_OP_WIDTH(op->data) << CQSPI_REG_RD_INSTR_TYPE_DATA_LSB;
 
 	return rdreg;
 }
 
-static unsigned int cqspi_calc_dummy(const struct spi_mem_op *op, bool dtr)
+static unsigned int cqspi_calc_dummy(const struct spi_mem_op *op)
 {
 	unsigned int dummy_clk;
 
@@ -362,66 +360,12 @@ static unsigned int cqspi_calc_dummy(const struct spi_mem_op *op, bool dtr)
 		return 0;
 
 	dummy_clk = op->dummy.nbytes * (8 / op->dummy.buswidth);
-	if (dtr)
+	if (op->cmd.dtr)
 		dummy_clk /= 2;
 
 	return dummy_clk;
 }
 
-static int cqspi_set_protocol(struct cqspi_flash_pdata *f_pdata,
-			      const struct spi_mem_op *op)
-{
-	/*
-	 * For an op to be DTR, cmd phase along with every other non-empty
-	 * phase should have dtr field set to 1. If an op phase has zero
-	 * nbytes, ignore its dtr field; otherwise, check its dtr field.
-	 */
-	f_pdata->dtr = op->cmd.dtr &&
-		       (!op->addr.nbytes || op->addr.dtr) &&
-		       (!op->data.nbytes || op->data.dtr);
-
-	f_pdata->inst_width = 0;
-	if (op->cmd.buswidth)
-		f_pdata->inst_width = ilog2(op->cmd.buswidth);
-
-	f_pdata->addr_width = 0;
-	if (op->addr.buswidth)
-		f_pdata->addr_width = ilog2(op->addr.buswidth);
-
-	f_pdata->data_width = 0;
-	if (op->data.buswidth)
-		f_pdata->data_width = ilog2(op->data.buswidth);
-
-	/* Right now we only support 8-8-8 DTR mode. */
-	if (f_pdata->dtr) {
-		switch (op->cmd.buswidth) {
-		case 0:
-		case 8:
-			break;
-		default:
-			return -EINVAL;
-		}
-
-		switch (op->addr.buswidth) {
-		case 0:
-		case 8:
-			break;
-		default:
-			return -EINVAL;
-		}
-
-		switch (op->data.buswidth) {
-		case 0:
-		case 8:
-			break;
-		default:
-			return -EINVAL;
-		}
-	}
-
-	return 0;
-}
-
 static int cqspi_wait_idle(struct cqspi_st *cqspi)
 {
 	const unsigned int poll_idle_retry = 3;
@@ -503,8 +447,7 @@ static int cqspi_setup_opcode_ext(struct cqspi_flash_pdata *f_pdata,
 }
 
 static int cqspi_enable_dtr(struct cqspi_flash_pdata *f_pdata,
-			    const struct spi_mem_op *op, unsigned int shift,
-			    bool enable)
+			    const struct spi_mem_op *op, unsigned int shift)
 {
 	struct cqspi_st *cqspi = f_pdata->cqspi;
 	void __iomem *reg_base = cqspi->iobase;
@@ -517,7 +460,7 @@ static int cqspi_enable_dtr(struct cqspi_flash_pdata *f_pdata,
 	 * 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) {
+	if (op->cmd.dtr) {
 		reg |= CQSPI_REG_CONFIG_DTR_PROTO;
 		reg |= CQSPI_REG_CONFIG_DUAL_OPCODE;
 
@@ -549,12 +492,7 @@ 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);
+	status = cqspi_enable_dtr(f_pdata, op, CQSPI_REG_OP_EXT_STIG_LSB);
 	if (status)
 		return status;
 
@@ -565,17 +503,17 @@ static int cqspi_command_read(struct cqspi_flash_pdata *f_pdata,
 		return -EINVAL;
 	}
 
-	if (f_pdata->dtr)
+	if (op->cmd.dtr)
 		opcode = op->cmd.opcode >> 8;
 	else
 		opcode = op->cmd.opcode;
 
 	reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
 
-	rdreg = cqspi_calc_rdreg(f_pdata);
+	rdreg = cqspi_calc_rdreg(op);
 	writel(rdreg, reg_base + CQSPI_REG_RD_INSTR);
 
-	dummy_clk = cqspi_calc_dummy(op, f_pdata->dtr);
+	dummy_clk = cqspi_calc_dummy(op);
 	if (dummy_clk > CQSPI_DUMMY_CLKS_MAX)
 		return -EOPNOTSUPP;
 
@@ -622,12 +560,7 @@ static int cqspi_command_write(struct cqspi_flash_pdata *f_pdata,
 	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);
+	ret = cqspi_enable_dtr(f_pdata, op, CQSPI_REG_OP_EXT_STIG_LSB);
 	if (ret)
 		return ret;
 
@@ -638,10 +571,10 @@ static int cqspi_command_write(struct cqspi_flash_pdata *f_pdata,
 		return -EINVAL;
 	}
 
-	reg = cqspi_calc_rdreg(f_pdata);
+	reg = cqspi_calc_rdreg(op);
 	writel(reg, reg_base + CQSPI_REG_RD_INSTR);
 
-	if (f_pdata->dtr)
+	if (op->cmd.dtr)
 		opcode = op->cmd.opcode >> 8;
 	else
 		opcode = op->cmd.opcode;
@@ -688,21 +621,20 @@ static int cqspi_read_setup(struct cqspi_flash_pdata *f_pdata,
 	int ret;
 	u8 opcode;
 
-	ret = cqspi_enable_dtr(f_pdata, op, CQSPI_REG_OP_EXT_READ_LSB,
-			       f_pdata->dtr);
+	ret = cqspi_enable_dtr(f_pdata, op, CQSPI_REG_OP_EXT_READ_LSB);
 	if (ret)
 		return ret;
 
-	if (f_pdata->dtr)
+	if (op->cmd.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);
+	reg |= cqspi_calc_rdreg(op);
 
 	/* Setup dummy clock cycles */
-	dummy_clk = cqspi_calc_dummy(op, f_pdata->dtr);
+	dummy_clk = cqspi_calc_dummy(op);
 
 	if (dummy_clk > CQSPI_DUMMY_CLKS_MAX)
 		return -EOPNOTSUPP;
@@ -947,22 +879,21 @@ static int cqspi_write_setup(struct cqspi_flash_pdata *f_pdata,
 	void __iomem *reg_base = cqspi->iobase;
 	u8 opcode;
 
-	ret = cqspi_enable_dtr(f_pdata, op, CQSPI_REG_OP_EXT_WRITE_LSB,
-			       f_pdata->dtr);
+	ret = cqspi_enable_dtr(f_pdata, op, CQSPI_REG_OP_EXT_WRITE_LSB);
 	if (ret)
 		return ret;
 
-	if (f_pdata->dtr)
+	if (op->cmd.dtr)
 		opcode = op->cmd.opcode >> 8;
 	else
 		opcode = op->cmd.opcode;
 
 	/* Set opcode. */
 	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;
+	reg |= CQSPI_OP_WIDTH(op->data) << CQSPI_REG_WR_INSTR_TYPE_DATA_LSB;
+	reg |= CQSPI_OP_WIDTH(op->addr) << CQSPI_REG_WR_INSTR_TYPE_ADDR_LSB;
 	writel(reg, reg_base + CQSPI_REG_WR_INSTR);
-	reg = cqspi_calc_rdreg(f_pdata);
+	reg = cqspi_calc_rdreg(op);
 	writel(reg, reg_base + CQSPI_REG_RD_INSTR);
 
 	/*
@@ -1244,10 +1175,6 @@ static ssize_t cqspi_write(struct cqspi_flash_pdata *f_pdata,
 	const u_char *buf = op->data.buf.out;
 	int ret;
 
-	ret = cqspi_set_protocol(f_pdata, op);
-	if (ret)
-		return ret;
-
 	ret = cqspi_write_setup(f_pdata, op);
 	if (ret)
 		return ret;
@@ -1260,7 +1187,7 @@ static ssize_t cqspi_write(struct cqspi_flash_pdata *f_pdata,
 	 * mode. So, we can not use direct mode when in DTR mode for writing
 	 * data.
 	 */
-	if (!f_pdata->dtr && cqspi->use_direct_mode &&
+	if (!op->cmd.dtr && cqspi->use_direct_mode &&
 	    ((to + len) <= cqspi->ahb_size)) {
 		memcpy_toio(cqspi->ahb_base + to, buf, len);
 		return cqspi_wait_idle(cqspi);
@@ -1348,9 +1275,6 @@ static ssize_t cqspi_read(struct cqspi_flash_pdata *f_pdata,
 	int ret;
 
 	ddata = of_device_get_match_data(dev);
-	ret = cqspi_set_protocol(f_pdata, op);
-	if (ret)
-		return ret;
 
 	ret = cqspi_read_setup(f_pdata, op);
 	if (ret)
-- 
2.25.1