[PATCH 17/21] e1000: Refactor Flash/EEPROM reading code

[Andrey Smirnov <andrew.smirnov@gmail.com>]

Refactor Flash/EEPROM reading code to use vtable with pointers to
small, specialized functions based on the flash class instead of big
monolithic funtions whose behaviour is driven by a number of flags and
variables.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 drivers/net/e1000/e1000.h  |   9 +-
 drivers/net/e1000/eeprom.c | 312 +++++++++++++++++++++++++++------------------
 2 files changed, 195 insertions(+), 126 deletions(-)

diff --git a/drivers/net/e1000/e1000.h b/drivers/net/e1000/e1000.h
index 2eb20f1..6b7cf82 100644
--- a/drivers/net/e1000/e1000.h
+++ b/drivers/net/e1000/e1000.h
@@ -682,13 +682,20 @@ struct e1000_tx_desc {
 #define E1000_82542_FFMT     E1000_FFMT
 #define E1000_82542_FFVT     E1000_FFVT
 
+struct e1000_hw;
+
 struct e1000_eeprom_info {
 	e1000_eeprom_type type;
 	uint16_t word_size;
 	uint16_t opcode_bits;
 	uint16_t address_bits;
 	uint16_t delay_usec;
-	bool use_eerd;
+
+	int32_t (*acquire) (struct e1000_hw *hw);
+	void    (*release) (struct e1000_hw *hw);
+
+	int32_t (*read) (struct e1000_hw *hw, uint16_t offset,
+			 uint16_t words, uint16_t *data);
 };
 
 #define E1000_EEPROM_SWDPIN0   0x0001	/* SWDPIN 0 EEPROM Value */
diff --git a/drivers/net/e1000/eeprom.c b/drivers/net/e1000/eeprom.c
index 0896fd6..b051a9b 100644
--- a/drivers/net/e1000/eeprom.c
+++ b/drivers/net/e1000/eeprom.c
@@ -4,6 +4,18 @@
 
 #include "e1000.h"
 
+static void e1000_release_eeprom_spi(struct e1000_hw *hw);
+static int32_t e1000_read_eeprom_spi(struct e1000_hw *hw, uint16_t offset,
+				     uint16_t words, uint16_t *data);
+static void e1000_release_eeprom_microwire(struct e1000_hw *hw);
+static int32_t e1000_read_eeprom_microwire(struct e1000_hw *hw, uint16_t offset,
+					   uint16_t words, uint16_t *data);
+
+static int32_t e1000_read_eeprom_eerd(struct e1000_hw *hw, uint16_t offset,
+				      uint16_t words, uint16_t *data);
+static int32_t e1000_spi_eeprom_ready(struct e1000_hw *hw);
+static void e1000_release_eeprom(struct e1000_hw *hw);
+
 
 
 /******************************************************************************
@@ -201,28 +213,22 @@ static bool e1000_is_onboard_nvm_eeprom(struct e1000_hw *hw)
 	return true;
 }
 
-/******************************************************************************
- * Prepares EEPROM for access
- *
- * hw - Struct containing variables accessed by shared code
- *
- * Lowers EEPROM clock. Clears input pin. Sets the chip select pin. This
- * function should be called before issuing a command to the EEPROM.
- *****************************************************************************/
-static int32_t e1000_acquire_eeprom(struct e1000_hw *hw)
+static int32_t
+e1000_acquire_eeprom_spi_microwire_prologue(struct e1000_hw *hw)
 {
-	struct e1000_eeprom_info *eeprom = &hw->eeprom;
-	uint32_t eecd, i = 0;
-
-	DEBUGFUNC();
+	uint32_t eecd;
 
 	if (e1000_swfw_sync_acquire(hw, E1000_SWFW_EEP_SM))
 		return -E1000_ERR_SWFW_SYNC;
+
 	eecd = e1000_read_reg(hw, E1000_EECD);
 
 	/* Request EEPROM Access */
-	if (hw->mac_type > e1000_82544 && hw->mac_type != e1000_82573 &&
-			hw->mac_type != e1000_82574) {
+	if (hw->mac_type > e1000_82544  &&
+	    hw->mac_type != e1000_82573 &&
+	    hw->mac_type != e1000_82574) {
+		int i = 0;
+
 		eecd |= E1000_EECD_REQ;
 		e1000_write_reg(hw, E1000_EECD, eecd);
 		eecd = e1000_read_reg(hw, E1000_EECD);
@@ -240,26 +246,57 @@ static int32_t e1000_acquire_eeprom(struct e1000_hw *hw)
 		}
 	}
 
-	/* Setup EEPROM for Read/Write */
+	return E1000_SUCCESS;
+}
+
+static int32_t e1000_acquire_eeprom_spi(struct e1000_hw *hw)
+{
+	int32_t ret;
+	uint32_t eecd;
 
-	if (eeprom->type == e1000_eeprom_microwire) {
-		/* Clear SK and DI */
-		eecd &= ~(E1000_EECD_DI | E1000_EECD_SK);
-		e1000_write_reg(hw, E1000_EECD, eecd);
+	ret = e1000_acquire_eeprom_spi_microwire_prologue(hw);
+	if (ret != E1000_SUCCESS)
+		return ret;
 
-		/* Set CS */
-		eecd |= E1000_EECD_CS;
-		e1000_write_reg(hw, E1000_EECD, eecd);
-	} else if (eeprom->type == e1000_eeprom_spi) {
-		/* Clear SK and CS */
-		eecd &= ~(E1000_EECD_CS | E1000_EECD_SK);
-		e1000_write_reg(hw, E1000_EECD, eecd);
-		udelay(1);
-	}
+	eecd = e1000_read_reg(hw, E1000_EECD);
+
+	/* Clear SK and CS */
+	eecd &= ~(E1000_EECD_CS | E1000_EECD_SK);
+	e1000_write_reg(hw, E1000_EECD, eecd);
+	udelay(1);
 
 	return E1000_SUCCESS;
 }
 
+static int32_t e1000_acquire_eeprom_microwire(struct e1000_hw *hw)
+{
+	int ret;
+	uint32_t eecd;
+
+	ret = e1000_acquire_eeprom_spi_microwire_prologue(hw);
+	if (ret != E1000_SUCCESS)
+		return ret;
+
+	eecd = e1000_read_reg(hw, E1000_EECD);
+	/* Clear SK and DI */
+	eecd &= ~(E1000_EECD_DI | E1000_EECD_SK);
+	e1000_write_reg(hw, E1000_EECD, eecd);
+
+	/* Set CS */
+	eecd |= E1000_EECD_CS;
+	e1000_write_reg(hw, E1000_EECD, eecd);
+
+	return E1000_SUCCESS;
+}
+
+static int32_t e1000_acquire_eeprom(struct e1000_hw *hw)
+{
+	if (hw->eeprom.acquire)
+		return hw->eeprom.acquire(hw);
+	else
+		return E1000_SUCCESS;
+}
+
 static void e1000_eeprom_uses_spi(struct e1000_eeprom_info *eeprom,
 				  uint32_t eecd)
 {
@@ -272,7 +309,9 @@ static void e1000_eeprom_uses_spi(struct e1000_eeprom_info *eeprom,
 		eeprom->address_bits = 8;
 	}
 
-	eeprom->use_eerd = false;
+	eeprom->acquire = e1000_acquire_eeprom_spi;
+	eeprom->release = e1000_release_eeprom_spi;
+	eeprom->read = e1000_read_eeprom_spi;
 }
 
 static void e1000_eeprom_uses_microwire(struct e1000_eeprom_info *eeprom,
@@ -288,7 +327,10 @@ static void e1000_eeprom_uses_microwire(struct e1000_eeprom_info *eeprom,
 		eeprom->word_size = 64;
 		eeprom->address_bits = 6;
 	}
-	eeprom->use_eerd = false;
+
+	eeprom->acquire = e1000_acquire_eeprom_microwire;
+	eeprom->release = e1000_release_eeprom_microwire;
+	eeprom->read = e1000_read_eeprom_microwire;
 }
 
 
@@ -342,8 +384,7 @@ int32_t e1000_init_eeprom_params(struct e1000_hw *hw)
 		if (e1000_is_onboard_nvm_eeprom(hw)) {
 			e1000_eeprom_uses_spi(eeprom, eecd);
 		} else {
-			eeprom->use_eerd = true;
-
+			eeprom->read = e1000_read_eeprom_eerd;
 			eeprom->type = e1000_eeprom_flash;
 			eeprom->word_size = 2048;
 
@@ -355,7 +396,7 @@ int32_t e1000_init_eeprom_params(struct e1000_hw *hw)
 		break;
 	case e1000_80003es2lan:
 		eeprom->type = e1000_eeprom_spi;
-		eeprom->use_eerd = true;
+		eeprom->read = e1000_read_eeprom_eerd;
 		break;
 	case e1000_igb:
 		if (eecd & E1000_EECD_I210_FLASH_DETECTED) {
@@ -365,7 +406,7 @@ int32_t e1000_init_eeprom_params(struct e1000_hw *hw)
 			eeprom->type = e1000_eeprom_invm;
 		}
 
-		eeprom->use_eerd = true;
+		eeprom->read = e1000_read_eeprom_eerd;
 		break;
 	default:
 		break;
@@ -464,41 +505,73 @@ static int32_t e1000_read_eeprom_eerd(struct e1000_hw *hw,
 	return error;
 }
 
-static void e1000_release_eeprom(struct e1000_hw *hw)
+static int32_t e1000_read_eeprom_spi(struct e1000_hw *hw,
+				     uint16_t offset,
+				     uint16_t words,
+				     uint16_t *data)
 {
-	uint32_t eecd;
+	unsigned int i;
+	uint16_t word_in;
+	uint8_t read_opcode = EEPROM_READ_OPCODE_SPI;
 
-	DEBUGFUNC();
+	if (e1000_spi_eeprom_ready(hw)) {
+		e1000_release_eeprom(hw);
+		return -E1000_ERR_EEPROM;
+	}
 
-	eecd = e1000_read_reg(hw, E1000_EECD);
+	e1000_standby_eeprom(hw);
 
-	if (hw->eeprom.type == e1000_eeprom_spi) {
-		eecd |= E1000_EECD_CS;  /* Pull CS high */
-		eecd &= ~E1000_EECD_SK; /* Lower SCK */
+	/* Some SPI eeproms use the 8th address bit embedded in
+	 * the opcode */
+	if ((hw->eeprom.address_bits == 8) && (offset >= 128))
+		read_opcode |= EEPROM_A8_OPCODE_SPI;
 
-		e1000_write_reg(hw, E1000_EECD, eecd);
+	/* Send the READ command (opcode + addr)  */
+	e1000_shift_out_ee_bits(hw, read_opcode, hw->eeprom.opcode_bits);
+	e1000_shift_out_ee_bits(hw, (uint16_t)(offset * 2),
+				hw->eeprom.address_bits);
 
-		udelay(hw->eeprom.delay_usec);
-	} else if (hw->eeprom.type == e1000_eeprom_microwire) {
-		/* cleanup eeprom */
+	/* Read the data.  The address of the eeprom internally
+	 * increments with each byte (spi) being read, saving on the
+	 * overhead of eeprom setup and tear-down.  The address
+	 * counter will roll over if reading beyond the size of
+	 * the eeprom, thus allowing the entire memory to be read
+	 * starting from any offset. */
+	for (i = 0; i < words; i++) {
+		word_in = e1000_shift_in_ee_bits(hw, 16);
+		data[i] = (word_in >> 8) | (word_in << 8);
+	}
 
-		/* CS on Microwire is active-high */
-		eecd &= ~(E1000_EECD_CS | E1000_EECD_DI);
+	return E1000_SUCCESS;
+}
 
-		e1000_write_reg(hw, E1000_EECD, eecd);
+static int32_t e1000_read_eeprom_microwire(struct e1000_hw *hw,
+					   uint16_t offset,
+					   uint16_t words,
+					   uint16_t *data)
+{
+	int i;
+	for (i = 0; i < words; i++) {
+		/* Send the READ command (opcode + addr)  */
+		e1000_shift_out_ee_bits(hw,
+					EEPROM_READ_OPCODE_MICROWIRE,
+					hw->eeprom.opcode_bits);
+		e1000_shift_out_ee_bits(hw, (uint16_t)(offset + i),
+					hw->eeprom.address_bits);
+
+		/* Read the data.  For microwire, each word requires
+		 * the overhead of eeprom setup and tear-down. */
+		data[i] = e1000_shift_in_ee_bits(hw, 16);
+		e1000_standby_eeprom(hw);
+	}
 
-		/* Rising edge of clock */
-		eecd |= E1000_EECD_SK;
-		e1000_write_reg(hw, E1000_EECD, eecd);
-		e1000_write_flush(hw);
-		udelay(hw->eeprom.delay_usec);
+	return E1000_SUCCESS;
+}
 
-		/* Falling edge of clock */
-		eecd &= ~E1000_EECD_SK;
-		e1000_write_reg(hw, E1000_EECD, eecd);
-		e1000_write_flush(hw);
-		udelay(hw->eeprom.delay_usec);
-	}
+static void
+e1000_release_eeprom_spi_microwire_epilogue(struct e1000_hw *hw)
+{
+	uint32_t eecd = e1000_read_reg(hw, E1000_EECD);
 
 	/* Stop requesting EEPROM access */
 	if (hw->mac_type > e1000_82544) {
@@ -506,6 +579,53 @@ static void e1000_release_eeprom(struct e1000_hw *hw)
 		e1000_write_reg(hw, E1000_EECD, eecd);
 	}
 }
+
+static void e1000_release_eeprom_microwire(struct e1000_hw *hw)
+{
+	uint32_t eecd = e1000_read_reg(hw, E1000_EECD);
+
+	/* cleanup eeprom */
+
+	/* CS on Microwire is active-high */
+	eecd &= ~(E1000_EECD_CS | E1000_EECD_DI);
+
+	e1000_write_reg(hw, E1000_EECD, eecd);
+
+	/* Rising edge of clock */
+	eecd |= E1000_EECD_SK;
+	e1000_write_reg(hw, E1000_EECD, eecd);
+	e1000_write_flush(hw);
+	udelay(hw->eeprom.delay_usec);
+
+	/* Falling edge of clock */
+	eecd &= ~E1000_EECD_SK;
+	e1000_write_reg(hw, E1000_EECD, eecd);
+	e1000_write_flush(hw);
+	udelay(hw->eeprom.delay_usec);
+
+
+	e1000_release_eeprom_spi_microwire_epilogue(hw);
+}
+
+static void e1000_release_eeprom_spi(struct e1000_hw *hw)
+{
+	uint32_t eecd = e1000_read_reg(hw, E1000_EECD);
+
+	eecd |= E1000_EECD_CS;  /* Pull CS high */
+	eecd &= ~E1000_EECD_SK; /* Lower SCK */
+
+	e1000_write_reg(hw, E1000_EECD, eecd);
+	udelay(hw->eeprom.delay_usec);
+
+	e1000_release_eeprom_spi_microwire_epilogue(hw);
+}
+
+static void e1000_release_eeprom(struct e1000_hw *hw)
+{
+	if (hw->eeprom.release)
+		hw->eeprom.release(hw);
+}
+
 /******************************************************************************
  * Reads a 16 bit word from the EEPROM.
  *
@@ -559,7 +679,7 @@ int32_t e1000_read_eeprom(struct e1000_hw *hw, uint16_t offset,
 			  uint16_t words, uint16_t *data)
 {
 	struct e1000_eeprom_info *eeprom = &hw->eeprom;
-	uint32_t i = 0;
+	int32_t ret;
 
 	DEBUGFUNC();
 
@@ -574,75 +694,17 @@ int32_t e1000_read_eeprom(struct e1000_hw *hw, uint16_t offset,
 		return -E1000_ERR_EEPROM;
 	}
 
-	/* EEPROM's that don't use EERD to read require us to bit-bang the SPI
-	 * directly. In this case, we need to acquire the EEPROM so that
-	 * FW or other port software does not interrupt.
-	 */
-	if (e1000_is_onboard_nvm_eeprom(hw) == true &&
-		hw->eeprom.use_eerd == false) {
-
-		/* Prepare the EEPROM for bit-bang reading */
+	if (eeprom->read) {
 		if (e1000_acquire_eeprom(hw) != E1000_SUCCESS)
 			return -E1000_ERR_EEPROM;
-	}
 
-	/* Eerd register EEPROM access requires no eeprom aquire/release */
-	if (eeprom->use_eerd == true)
-		return e1000_read_eeprom_eerd(hw, offset, words, data);
+		ret = eeprom->read(hw, offset, words, data);
+		e1000_release_eeprom(hw);
 
-	/* Set up the SPI or Microwire EEPROM for bit-bang reading.  We have
-	 * acquired the EEPROM at this point, so any returns should relase it */
-	if (eeprom->type == e1000_eeprom_spi) {
-		uint16_t word_in;
-		uint8_t read_opcode = EEPROM_READ_OPCODE_SPI;
-
-		if (e1000_spi_eeprom_ready(hw)) {
-			e1000_release_eeprom(hw);
-			return -E1000_ERR_EEPROM;
-		}
-
-		e1000_standby_eeprom(hw);
-
-		/* Some SPI eeproms use the 8th address bit embedded in
-		 * the opcode */
-		if ((eeprom->address_bits == 8) && (offset >= 128))
-			read_opcode |= EEPROM_A8_OPCODE_SPI;
-
-		/* Send the READ command (opcode + addr)  */
-		e1000_shift_out_ee_bits(hw, read_opcode, eeprom->opcode_bits);
-		e1000_shift_out_ee_bits(hw, (uint16_t)(offset*2),
-				eeprom->address_bits);
-
-		/* Read the data.  The address of the eeprom internally
-		 * increments with each byte (spi) being read, saving on the
-		 * overhead of eeprom setup and tear-down.  The address
-		 * counter will roll over if reading beyond the size of
-		 * the eeprom, thus allowing the entire memory to be read
-		 * starting from any offset. */
-		for (i = 0; i < words; i++) {
-			word_in = e1000_shift_in_ee_bits(hw, 16);
-			data[i] = (word_in >> 8) | (word_in << 8);
-		}
-	} else if (eeprom->type == e1000_eeprom_microwire) {
-		for (i = 0; i < words; i++) {
-			/* Send the READ command (opcode + addr)  */
-			e1000_shift_out_ee_bits(hw,
-				EEPROM_READ_OPCODE_MICROWIRE,
-				eeprom->opcode_bits);
-			e1000_shift_out_ee_bits(hw, (uint16_t)(offset + i),
-				eeprom->address_bits);
-
-			/* Read the data.  For microwire, each word requires
-			 * the overhead of eeprom setup and tear-down. */
-			data[i] = e1000_shift_in_ee_bits(hw, 16);
-			e1000_standby_eeprom(hw);
-		}
+		return ret;
+	} else {
+		return -ENOTSUPP;
 	}
-
-	/* End this read operation */
-	e1000_release_eeprom(hw);
-
-	return E1000_SUCCESS;
 }
 
 /******************************************************************************
-- 
2.5.5


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