sun6i: Add new p2wi controller driver

The A31 uses a new push-pull two wire interface, which features higher
transfer speeds (upto 6 MHz) in theory. While the hardware can burst 8
bytes each time, this driver will only see very little use and thus is
limited to single byte transmission only.

Signed-off-by: Oliver Schinagl <oliver@schinagl.nl>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

arch/arm/cpu/armv7/sunxi/Makefile

@@ -13,6 +13,7 @@ obj-y	+= clock.o
 obj-y	+= pinmux.o
 obj-$(CONFIG_MACH_SUN6I)	+= prcm.o
 obj-$(CONFIG_MACH_SUN8I)	+= prcm.o
+obj-$(CONFIG_MACH_SUN6I)	+= p2wi.o
 obj-$(CONFIG_MACH_SUN4I)	+= clock_sun4i.o
 obj-$(CONFIG_MACH_SUN5I)	+= clock_sun4i.o
 obj-$(CONFIG_MACH_SUN6I)	+= clock_sun6i.o

arch/arm/cpu/armv7/sunxi/p2wi.c

+/*
+ * Sunxi A31 Power Management Unit
+ *
+ * (C) Copyright 2013 Oliver Schinagl <oliver@schinagl.nl>
+ * http://linux-sunxi.org
+ *
+ * Based on sun6i sources and earlier U-Boot Allwiner A10 SPL work
+ *
+ * (C) Copyright 2006-2013
+ * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
+ * Berg Xing <bergxing@allwinnertech.com>
+ * Tom Cubie <tangliang@allwinnertech.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <asm/io.h>
+#include <asm/arch/cpu.h>
+#include <asm/arch/gpio.h>
+#include <asm/arch/p2wi.h>
+#include <asm/arch/prcm.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/sys_proto.h>
+
+void p2wi_init(void)
+{
+	struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUNXI_P2WI_BASE;
+
+	/* Enable p2wi and PIO clk, and de-assert their resets */
+	prcm_apb0_enable(PRCM_APB0_GATE_PIO | PRCM_APB0_GATE_P2WI);
+
+	sunxi_gpio_set_cfgpin(SUNXI_GPL(0), SUNXI_GPL0_R_P2WI_SCK);
+	sunxi_gpio_set_cfgpin(SUNXI_GPL(1), SUNXI_GPL1_R_P2WI_SDA);
+
+	/* Reset p2wi controller and set clock to CLKIN(12)/8 = 1.5 MHz */
+	writel(P2WI_CTRL_RESET, &p2wi->ctrl);
+	sdelay(0x100);
+	writel(P2WI_CC_SDA_OUT_DELAY(1) | P2WI_CC_CLK_DIV(8),
+	       &p2wi->cc);
+}
+
+int p2wi_change_to_p2wi_mode(u8 slave_addr, u8 ctrl_reg, u8 init_data)
+{
+	struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUNXI_P2WI_BASE;
+	unsigned long tmo = timer_get_us() + 1000000;
+
+	writel(P2WI_PM_DEV_ADDR(slave_addr) |
+	       P2WI_PM_CTRL_ADDR(ctrl_reg) |
+	       P2WI_PM_INIT_DATA(init_data) |
+	       P2WI_PM_INIT_SEND,
+	       &p2wi->pm);
+
+	while ((readl(&p2wi->pm) & P2WI_PM_INIT_SEND)) {
+		if (timer_get_us() > tmo)
+			return -ETIME;
+	}
+
+	return 0;
+}
+
+static int p2wi_await_trans(void)
+{
+	struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUNXI_P2WI_BASE;
+	unsigned long tmo = timer_get_us() + 1000000;
+	int ret;
+	u8 reg;
+
+	while (1) {
+		reg = readl(&p2wi->status);
+		if (reg & P2WI_STAT_TRANS_ERR) {
+			ret = -EIO;
+			break;
+		}
+		if (reg & P2WI_STAT_TRANS_DONE) {
+			ret = 0;
+			break;
+		}
+		if (timer_get_us() > tmo) {
+			ret = -ETIME;
+			break;
+		}
+	}
+	writel(reg, &p2wi->status); /* Clear status bits */
+	return ret;
+}
+
+int p2wi_read(const u8 addr, u8 *data)
+{
+	struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUNXI_P2WI_BASE;
+	int ret;
+
+	writel(P2WI_DATADDR_BYTE_1(addr), &p2wi->dataddr0);
+	writel(P2WI_DATA_NUM_BYTES(1) |
+	       P2WI_DATA_NUM_BYTES_READ, &p2wi->numbytes);
+	writel(P2WI_STAT_TRANS_DONE, &p2wi->status);
+	writel(P2WI_CTRL_TRANS_START, &p2wi->ctrl);
+
+	ret = p2wi_await_trans();
+
+	*data = readl(&p2wi->data0) & P2WI_DATA_BYTE_1_MASK;
+	return ret;
+}
+
+int p2wi_write(const u8 addr, u8 data)
+{
+	struct sunxi_p2wi_reg *p2wi = (struct sunxi_p2wi_reg *)SUNXI_P2WI_BASE;
+
+	writel(P2WI_DATADDR_BYTE_1(addr), &p2wi->dataddr0);
+	writel(P2WI_DATA_BYTE_1(data), &p2wi->data0);
+	writel(P2WI_DATA_NUM_BYTES(1), &p2wi->numbytes);
+	writel(P2WI_STAT_TRANS_DONE, &p2wi->status);
+	writel(P2WI_CTRL_TRANS_START, &p2wi->ctrl);
+
+	return p2wi_await_trans();
+}

arch/arm/include/asm/arch-sunxi/gpio.h

@@ -172,6 +172,9 @@ enum sunxi_gpio_number {
 
 #define SUN4I_GPI4_SDC3		2
 
+#define SUNXI_GPL0_R_P2WI_SCK	3
+#define SUNXI_GPL1_R_P2WI_SDA	3
+
 #define SUN8I_GPL2_R_UART_TX	2
 #define SUN8I_GPL3_R_UART_RX	2
 

arch/arm/include/asm/arch-sunxi/p2wi.h

+/*
+ * Sunxi platform Push-Push i2c register definition.
+ *
+ * (c) Copyright 2013 Oliver Schinagl <oliver@schinagl.nl>
+ * http://linux-sunxi.org
+ *
+ * (c)Copyright 2006-2013
+ * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
+ * Berg Xing <bergxing@allwinnertech.com>
+ * Tom Cubie <tangliang@allwinnertech.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _SUNXI_P2WI_H
+#define _SUNXI_P2WI_H
+
+#include <linux/types.h>
+
+#define P2WI_CTRL_RESET (0x1 << 0)
+#define P2WI_CTRL_IRQ_EN (0x1 << 1)
+#define P2WI_CTRL_TRANS_ABORT (0x1 << 6)
+#define P2WI_CTRL_TRANS_START (0x1 << 7)
+
+#define __P2WI_CC_CLK(n) (((n) & 0xff) << 0)
+#define P2WI_CC_CLK_MASK __P2WI_CC_CLK_DIV(0xff)
+#define __P2WI_CC_CLK_DIV(n) (((n) >> 1) - 1)
+#define P2WI_CC_CLK_DIV(n) \
+	__P2WI_CC_CLK(__P2WI_CC_CLK_DIV(n))
+#define P2WI_CC_SDA_OUT_DELAY(n) (((n) & 0x7) << 8)
+#define P2WI_CC_SDA_OUT_DELAY_MASK P2WI_CC_SDA_OUT_DELAY(0x7)
+
+#define P2WI_IRQ_TRANS_DONE (0x1 << 0)
+#define P2WI_IRQ_TRANS_ERR (0x1 << 1)
+#define P2WI_IRQ_LOAD_BUSY (0x1 << 2)
+
+#define P2WI_STAT_TRANS_DONE (0x1 << 0)
+#define P2WI_STAT_TRANS_ERR (0x1 << 1)
+#define P2WI_STAT_LOAD_BUSY (0x1 << 2)
+#define __P2WI_STAT_TRANS_ERR(n) (((n) & 0xff) << 8)
+#define P2WI_STAT_TRANS_ERR_MASK __P2WI_STAT_TRANS_ERR_ID(0xff)
+#define __P2WI_STAT_TRANS_ERR_BYTE_1 0x01
+#define __P2WI_STAT_TRANS_ERR_BYTE_2 0x02
+#define __P2WI_STAT_TRANS_ERR_BYTE_3 0x04
+#define __P2WI_STAT_TRANS_ERR_BYTE_4 0x08
+#define __P2WI_STAT_TRANS_ERR_BYTE_5 0x10
+#define __P2WI_STAT_TRANS_ERR_BYTE_6 0x20
+#define __P2WI_STAT_TRANS_ERR_BYTE_7 0x40
+#define __P2WI_STAT_TRANS_ERR_BYTE_8 0x80
+#define P2WI_STAT_TRANS_ERR_BYTE_1 \
+	__P2WI_STAT_TRANS_ERR(__P2WI_STAT_TRANS_ERR_BYTE_1)
+#define P2WI_STAT_TRANS_ERR_BYTE_2 \
+	__P2WI_STAT_TRANS_ERR(__P2WI_STAT_TRANS_ERR_BYTE_2)
+#define P2WI_STAT_TRANS_ERR_BYTE_3 \
+	__P2WI_STAT_TRANS_ERR(__P2WI_STAT_TRANS_ERR_BYTE_3)
+#define P2WI_STAT_TRANS_ERR_BYTE_4 \
+	__P2WI_STAT_TRANS_ERR(__P2WI_STAT_TRANS_ERR_BYTE_4)
+#define P2WI_STAT_TRANS_ERR_BYTE_5 \
+	__P2WI_STAT_TRANS_ERR(__P2WI_STAT_TRANS_ERR_BYTE_5)
+#define P2WI_STAT_TRANS_ERR_BYTE_6 \
+	__P2WI_STAT_TRANS_ERR(__P2WI_STAT_TRANS_ERR_BYTE_6)
+#define P2WI_STAT_TRANS_ERR_BYTE_7 \
+	__P2WI_STAT_TRANS_ERR(__P2WI_STAT_TRANS_ERR_BYTE_7)
+#define P2WI_STAT_TRANS_ERR_BYTE_8 \
+	__P2WI_STAT_TRANS_ERR(__P2WI_STAT_TRANS_ERR_BYTE_8)
+
+#define P2WI_DATADDR_BYTE_1(n) (((n) & 0xff) << 0)
+#define P2WI_DATADDR_BYTE_1_MASK P2WI_DATADDR_BYTE_1(0xff)
+#define P2WI_DATADDR_BYTE_2(n) (((n) & 0xff) << 8)
+#define P2WI_DATADDR_BYTE_2_MASK P2WI_DATADDR_BYTE_2(0xff)
+#define P2WI_DATADDR_BYTE_3(n) (((n) & 0xff) << 16)
+#define P2WI_DATADDR_BYTE_3_MASK P2WI_DATADDR_BYTE_3(0xff)
+#define P2WI_DATADDR_BYTE_4(n) (((n) & 0xff) << 24)
+#define P2WI_DATADDR_BYTE_4_MASK P2WI_DATADDR_BYTE_4(0xff)
+#define P2WI_DATADDR_BYTE_5(n) (((n) & 0xff) << 0)
+#define P2WI_DATADDR_BYTE_5_MASK P2WI_DATADDR_BYTE_5(0xff)
+#define P2WI_DATADDR_BYTE_6(n) (((n) & 0xff) << 8)
+#define P2WI_DATADDR_BYTE_6_MASK P2WI_DATADDR_BYTE_6(0xff)
+#define P2WI_DATADDR_BYTE_7(n) (((n) & 0xff) << 16)
+#define P2WI_DATADDR_BYTE_7_MASK P2WI_DATADDR_BYTE_7(0xff)
+#define P2WI_DATADDR_BYTE_8(n) (((n) & 0xff) << 24)
+#define P2WI_DATADDR_BYTE_8_MASK P2WI_DATADDR_BYTE_8(0xff)
+
+#define __P2WI_DATA_NUM_BYTES(n) (((n) & 0x7) << 0)
+#define P2WI_DATA_NUM_BYTES_MASK __P2WI_DATA_NUM_BYTES(0x7)
+#define P2WI_DATA_NUM_BYTES(n) __P2WI_DATA_NUM_BYTES((n) - 1)
+#define P2WI_DATA_NUM_BYTES_READ (0x1 << 4)
+
+#define P2WI_DATA_BYTE_1(n) (((n) & 0xff) << 0)
+#define P2WI_DATA_BYTE_1_MASK P2WI_DATA_BYTE_1(0xff)
+#define P2WI_DATA_BYTE_2(n) (((n) & 0xff) << 8)
+#define P2WI_DATA_BYTE_2_MASK P2WI_DATA_BYTE_2(0xff)
+#define P2WI_DATA_BYTE_3(n) (((n) & 0xff) << 16)
+#define P2WI_DATA_BYTE_3_MASK P2WI_DATA_BYTE_3(0xff)
+#define P2WI_DATA_BYTE_4(n) (((n) & 0xff) << 24)
+#define P2WI_DATA_BYTE_4_MASK P2WI_DATA_BYTE_4(0xff)
+#define P2WI_DATA_BYTE_5(n) (((n) & 0xff) << 0)
+#define P2WI_DATA_BYTE_5_MASK P2WI_DATA_BYTE_5(0xff)
+#define P2WI_DATA_BYTE_6(n) (((n) & 0xff) << 8)
+#define P2WI_DATA_BYTE_6_MASK P2WI_DATA_BYTE_6(0xff)
+#define P2WI_DATA_BYTE_7(n) (((n) & 0xff) << 16)
+#define P2WI_DATA_BYTE_7_MASK P2WI_DATA_BYTE_7(0xff)
+#define P2WI_DATA_BYTE_8(n) (((n) & 0xff) << 24)
+#define P2WI_DATA_BYTE_8_MASK P2WI_DATA_BYTE_8(0xff)
+
+#define P2WI_LINECTRL_SDA_CTRL_EN (0x1 << 0)
+#define P2WI_LINECTRL_SDA_OUT_HIGH (0x1 << 1)
+#define P2WI_LINECTRL_SCL_CTRL_EN (0x1 << 2)
+#define P2WI_LINECTRL_SCL_OUT_HIGH (0x1 << 3)
+#define P2WI_LINECTRL_SDA_STATE_HIGH (0x1 << 4)
+#define P2WI_LINECTRL_SCL_STATE_HIGH (0x1 << 5)
+
+#define P2WI_PM_DEV_ADDR(n) (((n) & 0xff) << 0)
+#define P2WI_PM_DEV_ADDR_MASK P2WI_PM_DEV_ADDR(0xff)
+#define P2WI_PM_CTRL_ADDR(n) (((n) & 0xff) << 8)
+#define P2WI_PM_CTRL_ADDR_MASK P2WI_PM_CTRL_ADDR(0xff)
+#define P2WI_PM_INIT_DATA(n) (((n) & 0xff) << 16)
+#define P2WI_PM_INIT_DATA_MASK P2WI_PM_INIT_DATA(0xff)
+#define P2WI_PM_INIT_SEND (0x1 << 31)
+
+struct sunxi_p2wi_reg {
+	u32 ctrl;	/* 0x00 control */
+	u32 cc;		/* 0x04 clock control */
+	u32 irq;	/* 0x08 interrupt */
+	u32 status;	/* 0x0c status */
+	u32 dataddr0;	/* 0x10 data address 0 */
+	u32 dataddr1;	/* 0x14 data address 1 */
+	u32 numbytes;	/* 0x18 num bytes */
+	u32 data0;	/* 0x1c data buffer 0 */
+	u32 data1;	/* 0x20 data buffer 1 */
+	u32 linectrl;	/* 0x24 line control */
+	u32 pm;		/* 0x28 power management */
+};
+
+void p2wi_init(void);
+int p2wi_change_to_p2wi_mode(u8 slave_addr, u8 ctrl_reg, u8 init_data);
+int p2wi_read(const u8 addr, u8 *data);
+int p2wi_write(const u8 addr, u8 data);
+
+#endif /* _SUNXI_P2WI_H */