openwrt/target/linux/ramips/patches-3.14/0051-SPI-MIPS-ralink-add-mt7621-support.patch

From 27b11d4f1888e1a3d6d75b46d4d5a4d86fc03891 Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Wed, 6 Aug 2014 10:53:40 +0200
Subject: [PATCH 51/57] SPI: MIPS: ralink: add mt7621 support

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 drivers/spi/spi-rt2880.c |  218 +++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 205 insertions(+), 13 deletions(-)

--- a/drivers/spi/spi-rt2880.c
+++ b/drivers/spi/spi-rt2880.c
@@ -21,8 +21,13 @@
 #include <linux/io.h>
 #include <linux/reset.h>
 #include <linux/spi/spi.h>
+#include <linux/of_device.h>
 #include <linux/platform_device.h>
 
+#include <ralink_regs.h>
+
+#define SPI_BPW_MASK(bits) BIT((bits) - 1)
+
 #define DRIVER_NAME			"spi-rt2880"
 /* only one slave is supported*/
 #define RALINK_NUM_CHIPSELECTS		1
@@ -63,6 +68,25 @@
 /* SPIFIFOSTAT register bit field */
 #define SPIFIFOSTAT_TXFULL		BIT(17)
 
+#define MT7621_SPI_TRANS	0x00
+#define SPITRANS_BUSY		BIT(16)
+#define MT7621_SPI_OPCODE	0x04
+#define MT7621_SPI_DATA0	0x08
+#define SPI_CTL_TX_RX_CNT_MASK	0xff
+#define SPI_CTL_START		BIT(8)
+#define MT7621_SPI_POLAR	0x38
+#define MT7621_SPI_MASTER	0x28
+#define MT7621_SPI_SPACE	0x3c
+
+struct rt2880_spi;
+
+struct rt2880_spi_ops {
+	void (*init_hw)(struct rt2880_spi *rs);
+	void (*set_cs)(struct rt2880_spi *rs, int enable);
+	int (*baudrate_set)(struct spi_device *spi, unsigned int speed);
+	unsigned int (*write_read)(struct spi_device *spi, struct list_head *list, struct spi_transfer *xfer);
+};
+
 struct rt2880_spi {
 	struct spi_master	*master;
 	void __iomem		*base;
@@ -70,6 +94,8 @@ struct rt2880_spi {
 	unsigned int		speed;
 	struct clk		*clk;
 	spinlock_t		lock;
+
+	struct rt2880_spi_ops	*ops;
 };
 
 static inline struct rt2880_spi *spidev_to_rt2880_spi(struct spi_device *spi)
@@ -149,6 +175,17 @@ static int rt2880_spi_baudrate_set(struc
 	return 0;
 }
 
+static int mt7621_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
+{
+/*	u32 master = rt2880_spi_read(rs, MT7621_SPI_MASTER);
+
+	// set default clock to hclk/5
+	master &= ~(0xfff << 16);
+	master |= 0x3 << 16;
+*/
+	return 0;
+}
+
 /*
  * called only when no transfer is active on the bus
  */
@@ -164,7 +201,7 @@ rt2880_spi_setup_transfer(struct spi_dev
 
 	if (rs->speed != speed) {
 		dev_dbg(&spi->dev, "speed_hz:%u\n", speed);
-		rc = rt2880_spi_baudrate_set(spi, speed);
+		rc = rs->ops->baudrate_set(spi, speed);
 		if (rc)
 			return rc;
 	}
@@ -180,6 +217,17 @@ static void rt2880_spi_set_cs(struct rt2
 		rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA);
 }
 
+static void mt7621_spi_set_cs(struct rt2880_spi *rs, int enable)
+{
+	u32 polar = rt2880_spi_read(rs, MT7621_SPI_POLAR);
+
+	if (enable)
+		polar |= 1;
+	else
+		polar &= ~1;
+	rt2880_spi_write(rs, MT7621_SPI_POLAR, polar);
+}
+
 static inline int rt2880_spi_wait_till_ready(struct rt2880_spi *rs)
 {
 	int i;
@@ -198,8 +246,26 @@ static inline int rt2880_spi_wait_till_r
 	return -ETIMEDOUT;
 }
 
+static inline int mt7621_spi_wait_till_ready(struct rt2880_spi *rs)
+{
+	int i;
+
+	for (i = 0; i < RALINK_SPI_WAIT_MAX_LOOP; i++) {
+		u32 status;
+
+		status = rt2880_spi_read(rs, MT7621_SPI_TRANS);
+		if ((status & SPITRANS_BUSY) == 0) {
+			return 0;
+		}
+		cpu_relax();
+		udelay(1);
+	}
+
+	return -ETIMEDOUT;
+}
+
 static unsigned int
-rt2880_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
+rt2880_spi_write_read(struct spi_device *spi, struct list_head *list, struct spi_transfer *xfer)
 {
 	struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
 	unsigned count = 0;
@@ -239,6 +305,100 @@ out:
 	return count;
 }
 
+static unsigned int
+mt7621_spi_write_read(struct spi_device *spi, struct list_head *list, struct spi_transfer *xfer)
+{
+	struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
+	struct spi_transfer *next = NULL;
+	const u8 *tx = xfer->tx_buf;
+	u8 *rx = NULL;
+	u32 trans;
+	int len = xfer->len;
+
+	if (!tx)
+		return 0;
+
+	if (!list_is_last(&xfer->transfer_list, list)) {
+		next = list_entry(xfer->transfer_list.next, struct spi_transfer, transfer_list);
+		rx = next->rx_buf;
+	}
+
+	trans = rt2880_spi_read(rs, MT7621_SPI_TRANS);
+	trans &= ~SPI_CTL_TX_RX_CNT_MASK;
+
+	if (tx) {
+		u32 data0 = 0, opcode = 0;
+
+		switch (xfer->len) {
+		case 8:
+			data0 |= tx[7] << 24;
+		case 7:
+			data0 |= tx[6] << 16;
+		case 6:
+			data0 |= tx[5] << 8;
+		case 5:
+			data0 |= tx[4];
+		case 4:
+			opcode |= tx[3] << 8;
+		case 3:
+			opcode |= tx[2] << 16;
+		case 2:
+			opcode |= tx[1] << 24;
+		case 1:
+			opcode |= tx[0];
+			break;
+
+		default:
+			dev_err(&spi->dev, "trying to write too many bytes: %d\n", next->len);
+			return -EINVAL;
+		}
+
+		rt2880_spi_write(rs, MT7621_SPI_DATA0, data0);
+		rt2880_spi_write(rs, MT7621_SPI_OPCODE, opcode);
+		trans |= xfer->len;
+	}
+
+	if (rx)
+		trans |= (next->len << 4);
+	rt2880_spi_write(rs, MT7621_SPI_TRANS, trans);
+	trans |= SPI_CTL_START;
+	rt2880_spi_write(rs, MT7621_SPI_TRANS, trans);
+
+	mt7621_spi_wait_till_ready(rs);
+
+	if (rx) {
+		u32 data0 = rt2880_spi_read(rs, MT7621_SPI_DATA0);
+		u32 opcode = rt2880_spi_read(rs, MT7621_SPI_OPCODE);
+
+		switch (next->len) {
+		case 8:
+			rx[7] = (opcode >> 24) & 0xff;
+		case 7:
+			rx[6] = (opcode >> 16) & 0xff;
+		case 6:
+			rx[5] = (opcode >> 8) & 0xff;
+		case 5:
+			rx[4] = opcode & 0xff;
+		case 4:
+			rx[3] = (data0 >> 24) & 0xff;
+		case 3:
+			rx[2] = (data0 >> 16) & 0xff;
+		case 2:
+			rx[1] = (data0 >> 8) & 0xff;
+		case 1:
+			rx[0] = data0 & 0xff;
+			break;
+
+		default:
+			dev_err(&spi->dev, "trying to read too many bytes: %d\n", next->len);
+			return -EINVAL;
+		}
+		len += next->len;
+	}
+
+	return len;
+}
+
 static int rt2880_spi_transfer_one_message(struct spi_master *master,
 					   struct spi_message *m)
 {
@@ -280,25 +440,25 @@ static int rt2880_spi_transfer_one_messa
 		}
 
 		if (!cs_active) {
-			rt2880_spi_set_cs(rs, 1);
+			rs->ops->set_cs(rs, 1);
 			cs_active = 1;
 		}
 
 		if (t->len)
-			m->actual_length += rt2880_spi_write_read(spi, t);
+			m->actual_length += rs->ops->write_read(spi, &m->transfers, t);
 
 		if (t->delay_usecs)
 			udelay(t->delay_usecs);
 
 		if (t->cs_change) {
-			rt2880_spi_set_cs(rs, 0);
+			rs->ops->set_cs(rs, 0);
 			cs_active = 0;
 		}
 	}
 
 msg_done:
 	if (cs_active)
-		rt2880_spi_set_cs(rs, 0);
+		rs->ops->set_cs(rs, 0);
 
 	m->status = status;
 	spi_finalize_current_message(master);
@@ -334,8 +494,41 @@ static void rt2880_spi_reset(struct rt28
 	rt2880_spi_write(rs, RAMIPS_SPI_CTL, SPICTL_HIZSDO | SPICTL_SPIENA);
 }
 
+static void mt7621_spi_reset(struct rt2880_spi *rs)
+{
+	u32 master = rt2880_spi_read(rs, MT7621_SPI_MASTER);
+
+	master &= ~(0xfff << 16);
+	master |= 3 << 16;
+
+	master |= 7 << 29;
+	rt2880_spi_write(rs, MT7621_SPI_MASTER, master);
+}
+
+static struct rt2880_spi_ops spi_ops[] = {
+	{
+		.init_hw = rt2880_spi_reset,
+		.set_cs = rt2880_spi_set_cs,
+		.baudrate_set = rt2880_spi_baudrate_set,
+		.write_read = rt2880_spi_write_read,
+	}, {
+		.init_hw = mt7621_spi_reset,
+		.set_cs = mt7621_spi_set_cs,
+		.baudrate_set = mt7621_spi_baudrate_set,
+		.write_read = mt7621_spi_write_read,
+	},
+};
+
+static const struct of_device_id rt2880_spi_match[] = {
+	{ .compatible = "ralink,rt2880-spi", .data = &spi_ops[0]},
+	{ .compatible = "ralink,mt7621-spi", .data = &spi_ops[1] },
+	{},
+};
+MODULE_DEVICE_TABLE(of, rt2880_spi_match);
+
 static int rt2880_spi_probe(struct platform_device *pdev)
 {
+        const struct of_device_id *match;
 	struct spi_master *master;
 	struct rt2880_spi *rs;
 	unsigned long flags;
@@ -344,6 +537,10 @@ static int rt2880_spi_probe(struct platf
 	int status = 0;
 	struct clk *clk;
 
+        match = of_match_device(rt2880_spi_match, &pdev->dev);
+	if (!match)
+		return -EINVAL;
+
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	base = devm_ioremap_resource(&pdev->dev, r);
 	if (IS_ERR(base))
@@ -382,12 +579,13 @@ static int rt2880_spi_probe(struct platf
 	rs->clk = clk;
 	rs->master = master;
 	rs->sys_freq = clk_get_rate(rs->clk);
+	rs->ops = (struct rt2880_spi_ops *) match->data;
 	dev_dbg(&pdev->dev, "sys_freq: %u\n", rs->sys_freq);
 	spin_lock_irqsave(&rs->lock, flags);
 
 	device_reset(&pdev->dev);
 
-	rt2880_spi_reset(rs);
+	rs->ops->init_hw(rs);
 
 	return spi_register_master(master);
 }
@@ -408,12 +606,6 @@ static int rt2880_spi_remove(struct plat
 
 MODULE_ALIAS("platform:" DRIVER_NAME);
 
-static const struct of_device_id rt2880_spi_match[] = {
-	{ .compatible = "ralink,rt2880-spi" },
-	{},
-};
-MODULE_DEVICE_TABLE(of, rt2880_spi_match);
-
 static struct platform_driver rt2880_spi_driver = {
 	.driver = {
 		.name = DRIVER_NAME,