i2c: Add a DM_I2C driver for the sun6i P2WI controller
authorSamuel Holland <samuel@sholland.org>
Fri, 8 Oct 2021 05:17:20 +0000 (00:17 -0500)
committerAndre Przywara <andre.przywara@arm.com>
Tue, 12 Oct 2021 08:50:56 +0000 (09:50 +0100)
This bus controller is used to communicate with an X-Powers AXP PMIC.
Currently, various drivers access PMIC registers through a platform-
specific non-DM "pmic_bus" interface, which depends on the legacy I2C
framework. In order to convert those drivers to use DM_PMIC, this bus
needs a DM_I2C driver.

Refactor the p2wi functions to take the base address as a parameter,
and implement both the existing interface (which is still needed in
SPL) and the DM_I2C interface on top of them.

The register for switching between I2C/P2WI/RSB mode is the same across
all PMIC variants. Move that to the common header, so it can be used by
both interface implementations.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
arch/arm/mach-sunxi/Kconfig
arch/arm/mach-sunxi/Makefile
arch/arm/mach-sunxi/p2wi.c [deleted file]
arch/arm/mach-sunxi/pmic_bus.c
drivers/i2c/Kconfig
drivers/i2c/Makefile
drivers/i2c/sun6i_p2wi.c [new file with mode: 0644]
include/axp_pmic.h

index da35cc8..f4a4528 100644 (file)
@@ -88,17 +88,6 @@ config DRAM_SUN50I_H616_UNKNOWN_FEATURE
          feature.
 endif
 
-config SUN6I_P2WI
-       bool "Allwinner sun6i internal P2WI controller"
-       help
-         If you say yes to this option, support will be included for the
-         P2WI (Push/Pull 2 Wire Interface) controller embedded in some sunxi
-         SOCs.
-         The P2WI looks like an SMBus controller (which supports only byte
-         accesses), except that it only supports one slave device.
-         This interface is used to connect to specific PMIC devices (like the
-         AXP221).
-
 config SUN6I_PRCM
        bool
        help
@@ -232,10 +221,11 @@ config MACH_SUN6I
        select ARCH_SUPPORT_PSCI
        select DRAM_SUN6I
        select PHY_SUN4I_USB
-       select SUN6I_P2WI
+       select SPL_I2C
        select SUN6I_PRCM
        select SUNXI_GEN_SUN6I
        select SUPPORT_SPL
+       select SYS_I2C_SUN6I_P2WI
        select ARMV7_BOOT_SEC_DEFAULT if OLD_SUNXI_KERNEL_COMPAT
 
 config MACH_SUN7I
index 3f081d9..c9312bb 100644 (file)
@@ -11,7 +11,6 @@ obj-y += clock.o
 obj-y  += cpu_info.o
 obj-y  += dram_helpers.o
 obj-y  += pinmux.o
-obj-$(CONFIG_SUN6I_P2WI)       += p2wi.o
 obj-$(CONFIG_SUN6I_PRCM)       += prcm.o
 obj-$(CONFIG_AXP_PMIC_BUS)     += pmic_bus.o
 obj-$(CONFIG_SUN8I_RSB)                += rsb.o
diff --git a/arch/arm/mach-sunxi/p2wi.c b/arch/arm/mach-sunxi/p2wi.c
deleted file mode 100644 (file)
index 7c5c122..0000000
+++ /dev/null
@@ -1,117 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0+
-/*
- * 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 Allwinner A10 SPL work
- *
- * (C) Copyright 2006-2013
- * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
- * Berg Xing <bergxing@allwinnertech.com>
- * Tom Cubie <tangliang@allwinnertech.com>
- */
-
-#include <common.h>
-#include <errno.h>
-#include <time.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 *)SUN6I_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), SUN6I_GPL0_R_P2WI_SCK);
-       sunxi_gpio_set_cfgpin(SUNXI_GPL(1), SUN6I_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 *)SUN6I_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 *)SUN6I_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 *)SUN6I_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 *)SUN6I_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();
-}
index 0394ce8..673a05f 100644 (file)
@@ -8,6 +8,7 @@
  * axp223 uses the rsb bus, these functions abstract this.
  */
 
+#include <axp_pmic.h>
 #include <common.h>
 #include <asm/arch/p2wi.h>
 #include <asm/arch/rsb.h>
@@ -21,8 +22,6 @@
 #define AXP305_I2C_ADDR                        0x36
 
 #define AXP221_CHIP_ADDR               0x68
-#define AXP221_CTRL_ADDR               0x3e
-#define AXP221_INIT_DATA               0x3e
 
 /* AXP818 device and runtime addresses are same as AXP223 */
 #define AXP223_DEVICE_ADDR             0x3a3
@@ -40,8 +39,8 @@ int pmic_bus_init(void)
 #if defined CONFIG_AXP221_POWER || defined CONFIG_AXP809_POWER || defined CONFIG_AXP818_POWER
 # ifdef CONFIG_MACH_SUN6I
        p2wi_init();
-       ret = p2wi_change_to_p2wi_mode(AXP221_CHIP_ADDR, AXP221_CTRL_ADDR,
-                                      AXP221_INIT_DATA);
+       ret = p2wi_change_to_p2wi_mode(AXP221_CHIP_ADDR, AXP_PMIC_MODE_REG,
+                                      AXP_PMIC_MODE_P2WI);
 # elif defined CONFIG_MACH_SUN8I_R40
        /* Nothing. R40 uses the AXP221s in I2C mode */
        ret = 0;
index 57cac44..0adf143 100644 (file)
@@ -575,6 +575,14 @@ config SYS_I2C_STM32F7
           _ Optional clock stretching
           _ Software reset
 
+config SYS_I2C_SUN6I_P2WI
+       bool "Allwinner sun6i P2WI controller"
+       depends on ARCH_SUNXI
+       help
+         Support for the P2WI (Push/Pull 2 Wire Interface) controller embedded
+         in the Allwinner A31 and A31s SOCs. This interface is used to connect
+         to specific devices like the X-Powers AXP221 PMIC.
+
 config SYS_I2C_SYNQUACER
        bool "Socionext SynQuacer I2C controller"
        depends on ARCH_SYNQUACER && DM_I2C
index 67841bf..0a2cc64 100644 (file)
@@ -43,6 +43,7 @@ obj-$(CONFIG_SYS_I2C_SANDBOX) += sandbox_i2c.o i2c-emul-uclass.o
 obj-$(CONFIG_SYS_I2C_SH) += sh_i2c.o
 obj-$(CONFIG_SYS_I2C_SOFT) += soft_i2c.o
 obj-$(CONFIG_SYS_I2C_STM32F7) += stm32f7_i2c.o
+obj-$(CONFIG_SYS_I2C_SUN6I_P2WI) += sun6i_p2wi.o
 obj-$(CONFIG_SYS_I2C_SYNQUACER) += synquacer_i2c.o
 obj-$(CONFIG_SYS_I2C_TEGRA) += tegra_i2c.o
 obj-$(CONFIG_SYS_I2C_UNIPHIER) += i2c-uniphier.o
diff --git a/drivers/i2c/sun6i_p2wi.c b/drivers/i2c/sun6i_p2wi.c
new file mode 100644 (file)
index 0000000..c9e1b3f
--- /dev/null
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * 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 Allwinner A10 SPL work
+ *
+ * (C) Copyright 2006-2013
+ * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
+ * Berg Xing <bergxing@allwinnertech.com>
+ * Tom Cubie <tangliang@allwinnertech.com>
+ */
+
+#include <axp_pmic.h>
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <i2c.h>
+#include <time.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/sys_proto.h>
+
+static int sun6i_p2wi_await_trans(struct sunxi_p2wi_reg *base)
+{
+       unsigned long tmo = timer_get_us() + 1000000;
+       int ret;
+       u8 reg;
+
+       while (1) {
+               reg = readl(&base->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, &base->status); /* Clear status bits */
+
+       return ret;
+}
+
+static int sun6i_p2wi_read(struct sunxi_p2wi_reg *base, const u8 addr, u8 *data)
+{
+       int ret;
+
+       writel(P2WI_DATADDR_BYTE_1(addr), &base->dataddr0);
+       writel(P2WI_DATA_NUM_BYTES(1) |
+              P2WI_DATA_NUM_BYTES_READ, &base->numbytes);
+       writel(P2WI_STAT_TRANS_DONE, &base->status);
+       writel(P2WI_CTRL_TRANS_START, &base->ctrl);
+
+       ret = sun6i_p2wi_await_trans(base);
+
+       *data = readl(&base->data0) & P2WI_DATA_BYTE_1_MASK;
+
+       return ret;
+}
+
+static int sun6i_p2wi_write(struct sunxi_p2wi_reg *base, const u8 addr, u8 data)
+{
+       writel(P2WI_DATADDR_BYTE_1(addr), &base->dataddr0);
+       writel(P2WI_DATA_BYTE_1(data), &base->data0);
+       writel(P2WI_DATA_NUM_BYTES(1), &base->numbytes);
+       writel(P2WI_STAT_TRANS_DONE, &base->status);
+       writel(P2WI_CTRL_TRANS_START, &base->ctrl);
+
+       return sun6i_p2wi_await_trans(base);
+}
+
+static int sun6i_p2wi_change_to_p2wi_mode(struct sunxi_p2wi_reg *base,
+                                         u8 slave_addr, u8 ctrl_reg,
+                                         u8 init_data)
+{
+       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,
+              &base->pm);
+
+       while ((readl(&base->pm) & P2WI_PM_INIT_SEND)) {
+               if (timer_get_us() > tmo)
+                       return -ETIME;
+       }
+
+       return 0;
+}
+
+static void sun6i_p2wi_init(struct sunxi_p2wi_reg *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), SUN6I_GPL0_R_P2WI_SCK);
+       sunxi_gpio_set_cfgpin(SUNXI_GPL(1), SUN6I_GPL1_R_P2WI_SDA);
+
+       /* Reset p2wi controller and set clock to CLKIN(12)/8 = 1.5 MHz */
+       writel(P2WI_CTRL_RESET, &base->ctrl);
+       sdelay(0x100);
+       writel(P2WI_CC_SDA_OUT_DELAY(1) | P2WI_CC_CLK_DIV(8),
+              &base->cc);
+}
+
+#if IS_ENABLED(CONFIG_AXP_PMIC_BUS)
+int p2wi_read(const u8 addr, u8 *data)
+{
+       struct sunxi_p2wi_reg *base = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
+
+       return sun6i_p2wi_read(base, addr, data);
+}
+
+int p2wi_write(const u8 addr, u8 data)
+{
+       struct sunxi_p2wi_reg *base = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
+
+       return sun6i_p2wi_write(base, addr, data);
+}
+
+int p2wi_change_to_p2wi_mode(u8 slave_addr, u8 ctrl_reg, u8 init_data)
+{
+       struct sunxi_p2wi_reg *base = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
+
+       return sun6i_p2wi_change_to_p2wi_mode(base, slave_addr, ctrl_reg,
+                                             init_data);
+}
+
+void p2wi_init(void)
+{
+       struct sunxi_p2wi_reg *base = (struct sunxi_p2wi_reg *)SUN6I_P2WI_BASE;
+
+       sun6i_p2wi_init(base);
+}
+#endif
+
+#if CONFIG_IS_ENABLED(DM_I2C)
+struct sun6i_p2wi_priv {
+       struct sunxi_p2wi_reg *base;
+};
+
+static int sun6i_p2wi_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
+{
+       struct sun6i_p2wi_priv *priv = dev_get_priv(bus);
+
+       /* The hardware only supports SMBus-style transfers. */
+       if (nmsgs == 2 && msg[1].flags == I2C_M_RD && msg[1].len == 1)
+               return sun6i_p2wi_read(priv->base,
+                                      msg[0].buf[0], &msg[1].buf[0]);
+
+       if (nmsgs == 1 && msg[0].len == 2)
+               return sun6i_p2wi_write(priv->base,
+                                       msg[0].buf[0], msg[0].buf[1]);
+
+       return -EINVAL;
+}
+
+static int sun6i_p2wi_probe_chip(struct udevice *bus, uint chip_addr,
+                                uint chip_flags)
+{
+       struct sun6i_p2wi_priv *priv = dev_get_priv(bus);
+
+       return sun6i_p2wi_change_to_p2wi_mode(priv->base, chip_addr,
+                                             AXP_PMIC_MODE_REG,
+                                             AXP_PMIC_MODE_P2WI);
+}
+
+static int sun6i_p2wi_probe(struct udevice *bus)
+{
+       struct sun6i_p2wi_priv *priv = dev_get_priv(bus);
+
+       priv->base = dev_read_addr_ptr(bus);
+
+       sun6i_p2wi_init(priv->base);
+
+       return 0;
+}
+
+static int sun6i_p2wi_child_pre_probe(struct udevice *child)
+{
+       struct dm_i2c_chip *chip = dev_get_parent_plat(child);
+
+       /* Ensure each transfer is for a single register. */
+       chip->flags |= DM_I2C_CHIP_RD_ADDRESS | DM_I2C_CHIP_WR_ADDRESS;
+
+       return 0;
+}
+
+static const struct dm_i2c_ops sun6i_p2wi_ops = {
+       .xfer           = sun6i_p2wi_xfer,
+       .probe_chip     = sun6i_p2wi_probe_chip,
+};
+
+static const struct udevice_id sun6i_p2wi_ids[] = {
+       { .compatible = "allwinner,sun6i-a31-p2wi" },
+       { /* sentinel */ }
+};
+
+U_BOOT_DRIVER(sun6i_p2wi) = {
+       .name                   = "sun6i_p2wi",
+       .id                     = UCLASS_I2C,
+       .of_match               = sun6i_p2wi_ids,
+       .probe                  = sun6i_p2wi_probe,
+       .child_pre_probe        = sun6i_p2wi_child_pre_probe,
+       .priv_auto              = sizeof(struct sun6i_p2wi_priv),
+       .ops                    = &sun6i_p2wi_ops,
+};
+#endif /* CONFIG_IS_ENABLED(DM_I2C) */
index 405044c..0db3e14 100644 (file)
@@ -6,6 +6,8 @@
  */
 #ifndef _AXP_PMIC_H_
 
+#include <stdbool.h>
+
 #ifdef CONFIG_AXP152_POWER
 #include <axp152.h>
 #endif
 #include <axp818.h>
 #endif
 
+#define AXP_PMIC_MODE_REG              0x3e
+#define AXP_PMIC_MODE_I2C              0x00
+#define AXP_PMIC_MODE_P2WI             0x3e
+
 int axp_set_dcdc1(unsigned int mvolt);
 int axp_set_dcdc2(unsigned int mvolt);
 int axp_set_dcdc3(unsigned int mvolt);