misc: xilinx_sdfec: Store driver config and state

Stores configuration based on parameters from the DT
node and values from the SD-FEC core plus reads
the default state from the SD-FEC core. To obtain
values from the core register read, write capabilities
have been added plus related register map details.

Tested-by: Dragan Cvetic <dragan.cvetic@xilinx.com>
Signed-off-by: Derek Kiernan <derek.kiernan@xilinx.com>
Signed-off-by: Dragan Cvetic <dragan.cvetic@xilinx.com>
Link: https://lore.kernel.org/r/1564216438-322406-2-git-send-email-dragan.cvetic@xilinx.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 437 insertions, 6 deletions

diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c
index f257d3812110..24d9f79fe073 100644
--- a/drivers/misc/xilinx_sdfec.c
+++ b/drivers/misc/xilinx_sdfec.c
@@ -20,11 +20,92 @@
 #include <linux/slab.h>
 #include <linux/clk.h>
 
+#include <uapi/misc/xilinx_sdfec.h>
+
 #define DEV_NAME_LEN 12
 
 static struct idr dev_idr;
 static struct mutex dev_idr_lock;
 
+/* Xilinx SDFEC Register Map */
+/* CODE_WRI_PROTECT Register */
+#define XSDFEC_CODE_WR_PROTECT_ADDR (0x4)
+
+/* ACTIVE Register */
+#define XSDFEC_ACTIVE_ADDR (0x8)
+#define XSDFEC_IS_ACTIVITY_SET (0x1)
+
+/* AXIS_WIDTH Register */
+#define XSDFEC_AXIS_WIDTH_ADDR (0xC)
+#define XSDFEC_AXIS_DOUT_WORDS_LSB (5)
+#define XSDFEC_AXIS_DOUT_WIDTH_LSB (3)
+#define XSDFEC_AXIS_DIN_WORDS_LSB (2)
+#define XSDFEC_AXIS_DIN_WIDTH_LSB (0)
+
+/* AXIS_ENABLE Register */
+#define XSDFEC_AXIS_ENABLE_ADDR (0x10)
+#define XSDFEC_AXIS_OUT_ENABLE_MASK (0x38)
+#define XSDFEC_AXIS_IN_ENABLE_MASK (0x7)
+#define XSDFEC_AXIS_ENABLE_MASK                                                \
+	(XSDFEC_AXIS_OUT_ENABLE_MASK | XSDFEC_AXIS_IN_ENABLE_MASK)
+
+/* FEC_CODE Register */
+#define XSDFEC_FEC_CODE_ADDR (0x14)
+
+/* ORDER Register Map */
+#define XSDFEC_ORDER_ADDR (0x18)
+
+/* Interrupt Status Register */
+#define XSDFEC_ISR_ADDR (0x1C)
+/* Interrupt Status Register Bit Mask */
+#define XSDFEC_ISR_MASK (0x3F)
+
+/* Write Only - Interrupt Enable Register */
+#define XSDFEC_IER_ADDR (0x20)
+/* Write Only - Interrupt Disable Register */
+#define XSDFEC_IDR_ADDR (0x24)
+/* Read Only - Interrupt Mask Register */
+#define XSDFEC_IMR_ADDR (0x28)
+
+/* ECC Interrupt Status Register */
+#define XSDFEC_ECC_ISR_ADDR (0x2C)
+/* Single Bit Errors */
+#define XSDFEC_ECC_ISR_SBE_MASK (0x7FF)
+/* PL Initialize Single Bit Errors */
+#define XSDFEC_PL_INIT_ECC_ISR_SBE_MASK (0x3C00000)
+/* Multi Bit Errors */
+#define XSDFEC_ECC_ISR_MBE_MASK (0x3FF800)
+/* PL Initialize Multi Bit Errors */
+#define XSDFEC_PL_INIT_ECC_ISR_MBE_MASK (0x3C000000)
+/* Multi Bit Error to Event Shift */
+#define XSDFEC_ECC_ISR_MBE_TO_EVENT_SHIFT (11)
+/* PL Initialize Multi Bit Error to Event Shift */
+#define XSDFEC_PL_INIT_ECC_ISR_MBE_TO_EVENT_SHIFT (4)
+/* ECC Interrupt Status Bit Mask */
+#define XSDFEC_ECC_ISR_MASK (XSDFEC_ECC_ISR_SBE_MASK | XSDFEC_ECC_ISR_MBE_MASK)
+/* ECC Interrupt Status PL Initialize Bit Mask */
+#define XSDFEC_PL_INIT_ECC_ISR_MASK                                            \
+	(XSDFEC_PL_INIT_ECC_ISR_SBE_MASK | XSDFEC_PL_INIT_ECC_ISR_MBE_MASK)
+/* ECC Interrupt Status All Bit Mask */
+#define XSDFEC_ALL_ECC_ISR_MASK                                                \
+	(XSDFEC_ECC_ISR_MASK | XSDFEC_PL_INIT_ECC_ISR_MASK)
+/* ECC Interrupt Status Single Bit Errors Mask */
+#define XSDFEC_ALL_ECC_ISR_SBE_MASK                                            \
+	(XSDFEC_ECC_ISR_SBE_MASK | XSDFEC_PL_INIT_ECC_ISR_SBE_MASK)
+/* ECC Interrupt Status Multi Bit Errors Mask */
+#define XSDFEC_ALL_ECC_ISR_MBE_MASK                                            \
+	(XSDFEC_ECC_ISR_MBE_MASK | XSDFEC_PL_INIT_ECC_ISR_MBE_MASK)
+
+/* Write Only - ECC Interrupt Enable Register */
+#define XSDFEC_ECC_IER_ADDR (0x30)
+/* Write Only - ECC Interrupt Disable Register */
+#define XSDFEC_ECC_IDR_ADDR (0x34)
+/* Read Only - ECC Interrupt Mask Register */
+#define XSDFEC_ECC_IMR_ADDR (0x38)
+
+/* BYPASS Register */
+#define XSDFEC_BYPASS_ADDR (0x3C)
+
 /**
  * struct xsdfec_clks - For managing SD-FEC clocks
  * @core_clk: Main processing clock for core
@@ -49,31 +130,237 @@ struct xsdfec_clks {
 
 /**
  * struct xsdfec_dev - Driver data for SDFEC
- * @regs: device physical base address
- * @dev: pointer to device struct
  * @miscdev: Misc device handle
- * @error_data_lock: Error counter and states spinlock
  * @clks: Clocks managed by the SDFEC driver
+ * @regs: device physical base address
+ * @dev: pointer to device struct
+ * @config: Configuration of the SDFEC device
  * @dev_name: Device name
+ * @state: State of the SDFEC device
+ * @error_data_lock: Error counter and states spinlock
  * @dev_id: Device ID
  *
  * This structure contains necessary state for SDFEC driver to operate
  */
 struct xsdfec_dev {
+	struct miscdevice miscdev;
+	struct xsdfec_clks clks;
 	void __iomem *regs;
 	struct device *dev;
-	struct miscdevice miscdev;
+	struct xsdfec_config config;
+	char dev_name[DEV_NAME_LEN];
+	enum xsdfec_state state;
 	/* Spinlock to protect state_updated and stats_updated */
 	spinlock_t error_data_lock;
-	struct xsdfec_clks clks;
-	char dev_name[DEV_NAME_LEN];
 	int dev_id;
 };
 
+static inline void xsdfec_regwrite(struct xsdfec_dev *xsdfec, u32 addr,
+				   u32 value)
+{
+	dev_dbg(xsdfec->dev, "Writing 0x%x to offset 0x%x", value, addr);
+	iowrite32(value, xsdfec->regs + addr);
+}
+
+static inline u32 xsdfec_regread(struct xsdfec_dev *xsdfec, u32 addr)
+{
+	u32 rval;
+
+	rval = ioread32(xsdfec->regs + addr);
+	dev_dbg(xsdfec->dev, "Read value = 0x%x from offset 0x%x", rval, addr);
+	return rval;
+}
+
+static void update_bool_config_from_reg(struct xsdfec_dev *xsdfec,
+					u32 reg_offset, u32 bit_num,
+					char *config_value)
+{
+	u32 reg_val;
+	u32 bit_mask = 1 << bit_num;
+
+	reg_val = xsdfec_regread(xsdfec, reg_offset);
+	*config_value = (reg_val & bit_mask) > 0;
+}
+
+static void update_config_from_hw(struct xsdfec_dev *xsdfec)
+{
+	u32 reg_value;
+	bool sdfec_started;
+
+	/* Update the Order */
+	reg_value = xsdfec_regread(xsdfec, XSDFEC_ORDER_ADDR);
+	xsdfec->config.order = reg_value;
+
+	update_bool_config_from_reg(xsdfec, XSDFEC_BYPASS_ADDR,
+				    0, /* Bit Number, maybe change to mask */
+				    &xsdfec->config.bypass);
+
+	update_bool_config_from_reg(xsdfec, XSDFEC_CODE_WR_PROTECT_ADDR,
+				    0, /* Bit Number */
+				    &xsdfec->config.code_wr_protect);
+
+	reg_value = xsdfec_regread(xsdfec, XSDFEC_IMR_ADDR);
+	xsdfec->config.irq.enable_isr = (reg_value & XSDFEC_ISR_MASK) > 0;
+
+	reg_value = xsdfec_regread(xsdfec, XSDFEC_ECC_IMR_ADDR);
+	xsdfec->config.irq.enable_ecc_isr =
+		(reg_value & XSDFEC_ECC_ISR_MASK) > 0;
+
+	reg_value = xsdfec_regread(xsdfec, XSDFEC_AXIS_ENABLE_ADDR);
+	sdfec_started = (reg_value & XSDFEC_AXIS_IN_ENABLE_MASK) > 0;
+	if (sdfec_started)
+		xsdfec->state = XSDFEC_STARTED;
+	else
+		xsdfec->state = XSDFEC_STOPPED;
+}
+
+static u32
+xsdfec_translate_axis_width_cfg_val(enum xsdfec_axis_width axis_width_cfg)
+{
+	u32 axis_width_field = 0;
+
+	switch (axis_width_cfg) {
+	case XSDFEC_1x128b:
+		axis_width_field = 0;
+		break;
+	case XSDFEC_2x128b:
+		axis_width_field = 1;
+		break;
+	case XSDFEC_4x128b:
+		axis_width_field = 2;
+		break;
+	}
+
+	return axis_width_field;
+}
+
+static u32 xsdfec_translate_axis_words_cfg_val(enum xsdfec_axis_word_include
+	axis_word_inc_cfg)
+{
+	u32 axis_words_field = 0;
+
+	if (axis_word_inc_cfg == XSDFEC_FIXED_VALUE ||
+	    axis_word_inc_cfg == XSDFEC_IN_BLOCK)
+		axis_words_field = 0;
+	else if (axis_word_inc_cfg == XSDFEC_PER_AXI_TRANSACTION)
+		axis_words_field = 1;
+
+	return axis_words_field;
+}
+
+static int xsdfec_cfg_axi_streams(struct xsdfec_dev *xsdfec)
+{
+	u32 reg_value;
+	u32 dout_words_field;
+	u32 dout_width_field;
+	u32 din_words_field;
+	u32 din_width_field;
+	struct xsdfec_config *config = &xsdfec->config;
+
+	/* translate config info to register values */
+	dout_words_field =
+		xsdfec_translate_axis_words_cfg_val(config->dout_word_include);
+	dout_width_field =
+		xsdfec_translate_axis_width_cfg_val(config->dout_width);
+	din_words_field =
+		xsdfec_translate_axis_words_cfg_val(config->din_word_include);
+	din_width_field =
+		xsdfec_translate_axis_width_cfg_val(config->din_width);
+
+	reg_value = dout_words_field << XSDFEC_AXIS_DOUT_WORDS_LSB;
+	reg_value |= dout_width_field << XSDFEC_AXIS_DOUT_WIDTH_LSB;
+	reg_value |= din_words_field << XSDFEC_AXIS_DIN_WORDS_LSB;
+	reg_value |= din_width_field << XSDFEC_AXIS_DIN_WIDTH_LSB;
+
+	xsdfec_regwrite(xsdfec, XSDFEC_AXIS_WIDTH_ADDR, reg_value);
+
+	return 0;
+}
+
 static const struct file_operations xsdfec_fops = {
 	.owner = THIS_MODULE,
 };
 
+static int xsdfec_parse_of(struct xsdfec_dev *xsdfec)
+{
+	struct device *dev = xsdfec->dev;
+	struct device_node *node = dev->of_node;
+	int rval;
+	const char *fec_code;
+	u32 din_width;
+	u32 din_word_include;
+	u32 dout_width;
+	u32 dout_word_include;
+
+	rval = of_property_read_string(node, "xlnx,sdfec-code", &fec_code);
+	if (rval < 0)
+		return rval;
+
+	if (!strcasecmp(fec_code, "ldpc"))
+		xsdfec->config.code = XSDFEC_LDPC_CODE;
+	else if (!strcasecmp(fec_code, "turbo"))
+		xsdfec->config.code = XSDFEC_TURBO_CODE;
+	else
+		return -EINVAL;
+
+	rval = of_property_read_u32(node, "xlnx,sdfec-din-words",
+				    &din_word_include);
+	if (rval < 0)
+		return rval;
+
+	if (din_word_include < XSDFEC_AXIS_WORDS_INCLUDE_MAX)
+		xsdfec->config.din_word_include = din_word_include;
+	else
+		return -EINVAL;
+
+	rval = of_property_read_u32(node, "xlnx,sdfec-din-width", &din_width);
+	if (rval < 0)
+		return rval;
+
+	switch (din_width) {
+	/* Fall through and set for valid values */
+	case XSDFEC_1x128b:
+	case XSDFEC_2x128b:
+	case XSDFEC_4x128b:
+		xsdfec->config.din_width = din_width;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	rval = of_property_read_u32(node, "xlnx,sdfec-dout-words",
+				    &dout_word_include);
+	if (rval < 0)
+		return rval;
+
+	if (dout_word_include < XSDFEC_AXIS_WORDS_INCLUDE_MAX)
+		xsdfec->config.dout_word_include = dout_word_include;
+	else
+		return -EINVAL;
+
+	rval = of_property_read_u32(node, "xlnx,sdfec-dout-width", &dout_width);
+	if (rval < 0)
+		return rval;
+
+	switch (dout_width) {
+	/* Fall through and set for valid values */
+	case XSDFEC_1x128b:
+	case XSDFEC_2x128b:
+	case XSDFEC_4x128b:
+		xsdfec->config.dout_width = dout_width;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* Write LDPC to CODE Register */
+	xsdfec_regwrite(xsdfec, XSDFEC_FEC_CODE_ADDR, xsdfec->config.code);
+
+	xsdfec_cfg_axi_streams(xsdfec);
+
+	return 0;
+}
+
 static int xsdfec_clk_init(struct platform_device *pdev,
 			   struct xsdfec_clks *clks)
 {
@@ -260,6 +547,12 @@ static int xsdfec_probe(struct platform_device *pdev)
 		goto err_xsdfec_dev;
 	}
 
+	err = xsdfec_parse_of(xsdfec);
+	if (err < 0)
+		goto err_xsdfec_dev;
+
+	update_config_from_hw(xsdfec);
+
 	/* Save driver private data */
 	platform_set_drvdata(pdev, xsdfec);
 
diff --git a/include/uapi/misc/xilinx_sdfec.h b/include/uapi/misc/xilinx_sdfec.h
new file mode 100644
index 000000000000..330ea25ddfa1
--- /dev/null
+++ b/include/uapi/misc/xilinx_sdfec.h
@@ -0,0 +1,138 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Xilinx SD-FEC
+ *
+ * Copyright (C) 2019 Xilinx, Inc.
+ *
+ * Description:
+ * This driver is developed for SDFEC16 IP. It provides a char device
+ * in sysfs and supports file operations like open(), close() and ioctl().
+ */
+#ifndef __XILINX_SDFEC_H__
+#define __XILINX_SDFEC_H__
+
+#include <linux/types.h>
+
+/**
+ * enum xsdfec_code - Code Type.
+ * @XSDFEC_TURBO_CODE: Driver is configured for Turbo mode.
+ * @XSDFEC_LDPC_CODE: Driver is configured for LDPC mode.
+ *
+ * This enum is used to indicate the mode of the driver. The mode is determined
+ * by checking which codes are set in the driver. Note that the mode cannot be
+ * changed by the driver.
+ */
+enum xsdfec_code {
+	XSDFEC_TURBO_CODE = 0,
+	XSDFEC_LDPC_CODE,
+};
+
+/**
+ * enum xsdfec_order - Order
+ * @XSDFEC_MAINTAIN_ORDER: Maintain order execution of blocks.
+ * @XSDFEC_OUT_OF_ORDER: Out-of-order execution of blocks.
+ *
+ * This enum is used to indicate whether the order of blocks can change from
+ * input to output.
+ */
+enum xsdfec_order {
+	XSDFEC_MAINTAIN_ORDER = 0,
+	XSDFEC_OUT_OF_ORDER,
+};
+
+/**
+ * enum xsdfec_state - State.
+ * @XSDFEC_INIT: Driver is initialized.
+ * @XSDFEC_STARTED: Driver is started.
+ * @XSDFEC_STOPPED: Driver is stopped.
+ * @XSDFEC_NEEDS_RESET: Driver needs to be reset.
+ * @XSDFEC_PL_RECONFIGURE: Programmable Logic needs to be recofigured.
+ *
+ * This enum is used to indicate the state of the driver.
+ */
+enum xsdfec_state {
+	XSDFEC_INIT = 0,
+	XSDFEC_STARTED,
+	XSDFEC_STOPPED,
+	XSDFEC_NEEDS_RESET,
+	XSDFEC_PL_RECONFIGURE,
+};
+
+/**
+ * enum xsdfec_axis_width - AXIS_WIDTH.DIN Setting for 128-bit width.
+ * @XSDFEC_1x128b: DIN data input stream consists of a 128-bit lane
+ * @XSDFEC_2x128b: DIN data input stream consists of two 128-bit lanes
+ * @XSDFEC_4x128b: DIN data input stream consists of four 128-bit lanes
+ *
+ * This enum is used to indicate the AXIS_WIDTH.DIN setting for 128-bit width.
+ * The number of lanes of the DIN data input stream depends upon the
+ * AXIS_WIDTH.DIN parameter.
+ */
+enum xsdfec_axis_width {
+	XSDFEC_1x128b = 1,
+	XSDFEC_2x128b = 2,
+	XSDFEC_4x128b = 4,
+};
+
+/**
+ * enum xsdfec_axis_word_include - Words Configuration.
+ * @XSDFEC_FIXED_VALUE: Fixed, the DIN_WORDS AXI4-Stream interface is removed
+ *			from the IP instance and is driven with the specified
+ *			number of words.
+ * @XSDFEC_IN_BLOCK: In Block, configures the IP instance to expect a single
+ *		     DIN_WORDS value per input code block. The DIN_WORDS
+ *		     interface is present.
+ * @XSDFEC_PER_AXI_TRANSACTION: Per Transaction, configures the IP instance to
+ * expect one DIN_WORDS value per input transaction on the DIN interface. The
+ * DIN_WORDS interface is present.
+ * @XSDFEC_AXIS_WORDS_INCLUDE_MAX: Used to indicate out of bound Words
+ *				   Configurations.
+ *
+ * This enum is used to specify the DIN_WORDS configuration.
+ */
+enum xsdfec_axis_word_include {
+	XSDFEC_FIXED_VALUE = 0,
+	XSDFEC_IN_BLOCK,
+	XSDFEC_PER_AXI_TRANSACTION,
+	XSDFEC_AXIS_WORDS_INCLUDE_MAX,
+};
+
+/**
+ * struct xsdfec_irq - Enabling or Disabling Interrupts.
+ * @enable_isr: If true enables the ISR
+ * @enable_ecc_isr: If true enables the ECC ISR
+ */
+struct xsdfec_irq {
+	__s8 enable_isr;
+	__s8 enable_ecc_isr;
+};
+
+/**
+ * struct xsdfec_config - Configuration of SD-FEC core.
+ * @code: The codes being used by the SD-FEC instance
+ * @order: Order of Operation
+ * @din_width: Width of the DIN AXI4-Stream
+ * @din_word_include: How DIN_WORDS are inputted
+ * @dout_width: Width of the DOUT AXI4-Stream
+ * @dout_word_include: HOW DOUT_WORDS are outputted
+ * @irq: Enabling or disabling interrupts
+ * @bypass: Is the core being bypassed
+ * @code_wr_protect: Is write protection of LDPC codes enabled
+ */
+struct xsdfec_config {
+	__u32 code;
+	__u32 order;
+	__u32 din_width;
+	__u32 din_word_include;
+	__u32 dout_width;
+	__u32 dout_word_include;
+	struct xsdfec_irq irq;
+	__s8 bypass;
+	__s8 code_wr_protect;
+};
+
+/*
+ * XSDFEC IOCTL List
+ */
+#define XSDFEC_MAGIC 'f'
+#endif /* __XILINX_SDFEC_H__ */