From 35780e860f7d4a5f33f6ceadf09038ee26f1ef43 Mon Sep 17 00:00:00 2001 From: Alexander Sverdlin Date: Mon, 14 Sep 2015 11:03:50 +0200 Subject: i2c: davinci: Optimize clock generation on Keystone SoC According to "KeyStone Architecture Inter-IC Control Bus User Guide", fixed additive part of frequency divisors (referred as "d" in the code and datasheet) always equals to 6, independent of module clock prescaler. module clock frequency master clock frequency = ---------------------- (ICCL + 6) + (ICCH + 6) It was not the case with original Davinci IP. Introduce new compatible property "ti,keystone-i2c", which triggers special handling in the driver. Without this change Keystone-based systems (having 204.8MHz input clock) choose prescaler 29 (PSC=28). Using d=5 in this case leads to bus bitrate ~353kHz instead of requested 400kHz. After correction, assuming d=6 bus rate is ~392kHz. This gives ~11% transfer rate increase. Signed-off-by: Alexander Sverdlin Reviewed-by: Grygorii Strashko Tested-by: Hemanth Guruva Reddy Tested-by: Lukasz Gemborowski Signed-off-by: Wolfram Sang --- Documentation/devicetree/bindings/i2c/i2c-davinci.txt | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/i2c/i2c-davinci.txt b/Documentation/devicetree/bindings/i2c/i2c-davinci.txt index a4e1cbc810c1..5b123e0e4cc2 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-davinci.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-davinci.txt @@ -1,10 +1,10 @@ -* Texas Instruments Davinci I2C +* Texas Instruments Davinci/Keystone I2C This file provides information, what the device node for the -davinci i2c interface contain. +davinci/keystone i2c interface contains. Required properties: -- compatible: "ti,davinci-i2c"; +- compatible: "ti,davinci-i2c" or "ti,keystone-i2c"; - reg : Offset and length of the register set for the device Recommended properties : -- cgit v1.2.3 From e7db0d34b38d56bbdb3d2d64c6233c53b77a3c6c Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Wed, 5 Aug 2015 15:18:25 +0200 Subject: i2c: rcar: add support for r8a7795 (R-Car H3) Enable the I2C core for this SoC. I add a new type because this version has new features (e.g. DMA) which will be added somewhen later. Signed-off-by: Wolfram Sang Tested-by: Kuninori Morimoto Signed-off-by: Wolfram Sang --- Documentation/devicetree/bindings/i2c/i2c-rcar.txt | 1 + drivers/i2c/busses/i2c-rcar.c | 3 +++ 2 files changed, 4 insertions(+) (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/i2c/i2c-rcar.txt b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt index 16b3e07aa98f..ea406eb20fa5 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-rcar.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-rcar.txt @@ -10,6 +10,7 @@ Required properties: "renesas,i2c-r8a7792" "renesas,i2c-r8a7793" "renesas,i2c-r8a7794" + "renesas,i2c-r8a7795" - reg: physical base address of the controller and length of memory mapped region. - interrupts: interrupt specifier. diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index dbedbff48b59..1921294afc87 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -100,6 +100,7 @@ enum rcar_i2c_type { I2C_RCAR_GEN1, I2C_RCAR_GEN2, + I2C_RCAR_GEN3, }; struct rcar_i2c_priv { @@ -176,6 +177,7 @@ static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, cdf_width = 2; break; case I2C_RCAR_GEN2: + case I2C_RCAR_GEN3: cdf_width = 3; break; default: @@ -573,6 +575,7 @@ static const struct of_device_id rcar_i2c_dt_ids[] = { { .compatible = "renesas,i2c-r8a7792", .data = (void *)I2C_RCAR_GEN2 }, { .compatible = "renesas,i2c-r8a7793", .data = (void *)I2C_RCAR_GEN2 }, { .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 }, + { .compatible = "renesas,i2c-r8a7795", .data = (void *)I2C_RCAR_GEN3 }, {}, }; MODULE_DEVICE_TABLE(of, rcar_i2c_dt_ids); -- cgit v1.2.3 From 7bb6da5a3d2dae725ed228a97dd65f82e3fbd934 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Wed, 5 Aug 2015 15:18:26 +0200 Subject: i2c: sh_mobile: add support for r8a7795 (R-Car H3) Enable the I2C core for this SoC. It is compitable to Gen2 SoCs, so reuse the settings. Signed-off-by: Wolfram Sang Tested-by: Kuninori Morimoto Signed-off-by: Wolfram Sang --- Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt | 1 + drivers/i2c/busses/i2c-sh_mobile.c | 1 + 2 files changed, 2 insertions(+) (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt b/Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt index 2bfc6e7ed094..214f94c25d37 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-sh_mobile.txt @@ -10,6 +10,7 @@ Required properties: - "renesas,iic-r8a7792" (R-Car V2H) - "renesas,iic-r8a7793" (R-Car M2-N) - "renesas,iic-r8a7794" (R-Car E2) + - "renesas,iic-r8a7795" (R-Car H3) - "renesas,iic-sh73a0" (SH-Mobile AG5) - reg : address start and address range size of device - interrupts : interrupt of device diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c index 47659a925e09..7d2bd3ec2d2d 100644 --- a/drivers/i2c/busses/i2c-sh_mobile.c +++ b/drivers/i2c/busses/i2c-sh_mobile.c @@ -836,6 +836,7 @@ static const struct of_device_id sh_mobile_i2c_dt_ids[] = { { .compatible = "renesas,iic-r8a7792", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-r8a7793", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-r8a7794", .data = &fast_clock_dt_config }, + { .compatible = "renesas,iic-r8a7795", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-sh73a0", .data = &fast_clock_dt_config }, {}, }; -- cgit v1.2.3 From dd6fd4a3279310bac214867e31848f47e13caa6f Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 23 Oct 2015 19:51:59 +0900 Subject: i2c: uniphier: add UniPhier FIFO-less I2C driver Add support for on-chip I2C controller used on old UniPhier SoCs such as PH1-LD4, PH1-sLD8, etc. This adapter is so simple that it has no FIFO in it. Signed-off-by: Masahiro Yamada Signed-off-by: Wolfram Sang --- .../devicetree/bindings/i2c/i2c-uniphier.txt | 25 ++ MAINTAINERS | 1 + drivers/i2c/busses/Kconfig | 8 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-uniphier.c | 441 +++++++++++++++++++++ 5 files changed, 476 insertions(+) create mode 100644 Documentation/devicetree/bindings/i2c/i2c-uniphier.txt create mode 100644 drivers/i2c/busses/i2c-uniphier.c (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/i2c/i2c-uniphier.txt b/Documentation/devicetree/bindings/i2c/i2c-uniphier.txt new file mode 100644 index 000000000000..26f9d95b3436 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-uniphier.txt @@ -0,0 +1,25 @@ +UniPhier I2C controller (FIFO-less) + +Required properties: +- compatible: should be "socionext,uniphier-i2c". +- #address-cells: should be 1. +- #size-cells: should be 0. +- reg: offset and length of the register set for the device. +- interrupts: a single interrupt specifier. +- clocks: phandle to the input clock. + +Optional properties: +- clock-frequency: desired I2C bus frequency in Hz. The maximum supported + value is 400000. Defaults to 100000 if not specified. + +Examples: + + i2c0: i2c@58400000 { + compatible = "socionext,uniphier-i2c"; + reg = <0x58400000 0x40>; + #address-cells = <1>; + #size-cells = <0>; + interrupts = <0 41 1>; + clocks = <&i2c_clk>; + clock-frequency = <100000>; + }; diff --git a/MAINTAINERS b/MAINTAINERS index 797236befd27..2f23aab10398 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1607,6 +1607,7 @@ L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers) S: Maintained F: arch/arm/boot/dts/uniphier* F: arch/arm/mach-uniphier/ +F: drivers/i2c/busses/i2c-uniphier* F: drivers/pinctrl/uniphier/ F: drivers/tty/serial/8250/8250_uniphier.c N: uniphier diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 14147ec6b790..6a40e1693dd4 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -902,6 +902,14 @@ config I2C_TEGRA If you say yes to this option, support will be included for the I2C controller embedded in NVIDIA Tegra SOCs +config I2C_UNIPHIER + tristate "UniPhier FIFO-less I2C controller" + depends on ARCH_UNIPHIER + help + If you say yes to this option, support will be included for + the UniPhier FIFO-less I2C interface embedded in PH1-LD4, PH1-sLD8, + or older UniPhier SoCs. + config I2C_VERSATILE tristate "ARM Versatile/Realview I2C bus support" depends on ARCH_VERSATILE || ARCH_REALVIEW || ARCH_VEXPRESS diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 6df3b303bd09..f9f090285681 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -87,6 +87,7 @@ obj-$(CONFIG_I2C_ST) += i2c-st.o obj-$(CONFIG_I2C_STU300) += i2c-stu300.o obj-$(CONFIG_I2C_SUN6I_P2WI) += i2c-sun6i-p2wi.o obj-$(CONFIG_I2C_TEGRA) += i2c-tegra.o +obj-$(CONFIG_I2C_UNIPHIER) += i2c-uniphier.o obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o obj-$(CONFIG_I2C_WMT) += i2c-wmt.o obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o diff --git a/drivers/i2c/busses/i2c-uniphier.c b/drivers/i2c/busses/i2c-uniphier.c new file mode 100644 index 000000000000..e3c3861c3325 --- /dev/null +++ b/drivers/i2c/busses/i2c-uniphier.c @@ -0,0 +1,441 @@ +/* + * Copyright (C) 2015 Masahiro Yamada + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include +#include + +#define UNIPHIER_I2C_DTRM 0x00 /* TX register */ +#define UNIPHIER_I2C_DTRM_IRQEN BIT(11) /* enable interrupt */ +#define UNIPHIER_I2C_DTRM_STA BIT(10) /* start condition */ +#define UNIPHIER_I2C_DTRM_STO BIT(9) /* stop condition */ +#define UNIPHIER_I2C_DTRM_NACK BIT(8) /* do not return ACK */ +#define UNIPHIER_I2C_DTRM_RD BIT(0) /* read transaction */ +#define UNIPHIER_I2C_DREC 0x04 /* RX register */ +#define UNIPHIER_I2C_DREC_MST BIT(14) /* 1 = master, 0 = slave */ +#define UNIPHIER_I2C_DREC_TX BIT(13) /* 1 = transmit, 0 = receive */ +#define UNIPHIER_I2C_DREC_STS BIT(12) /* stop condition detected */ +#define UNIPHIER_I2C_DREC_LRB BIT(11) /* no ACK */ +#define UNIPHIER_I2C_DREC_LAB BIT(9) /* arbitration lost */ +#define UNIPHIER_I2C_DREC_BBN BIT(8) /* bus not busy */ +#define UNIPHIER_I2C_MYAD 0x08 /* slave address */ +#define UNIPHIER_I2C_CLK 0x0c /* clock frequency control */ +#define UNIPHIER_I2C_BRST 0x10 /* bus reset */ +#define UNIPHIER_I2C_BRST_FOEN BIT(1) /* normal operation */ +#define UNIPHIER_I2C_BRST_RSCL BIT(0) /* release SCL */ +#define UNIPHIER_I2C_HOLD 0x14 /* hold time control */ +#define UNIPHIER_I2C_BSTS 0x18 /* bus status monitor */ +#define UNIPHIER_I2C_BSTS_SDA BIT(1) /* readback of SDA line */ +#define UNIPHIER_I2C_BSTS_SCL BIT(0) /* readback of SCL line */ +#define UNIPHIER_I2C_NOISE 0x1c /* noise filter control */ +#define UNIPHIER_I2C_SETUP 0x20 /* setup time control */ + +#define UNIPHIER_I2C_DEFAULT_SPEED 100000 +#define UNIPHIER_I2C_MAX_SPEED 400000 + +struct uniphier_i2c_priv { + struct completion comp; + struct i2c_adapter adap; + void __iomem *membase; + struct clk *clk; + unsigned int busy_cnt; +}; + +static irqreturn_t uniphier_i2c_interrupt(int irq, void *dev_id) +{ + struct uniphier_i2c_priv *priv = dev_id; + + /* + * This hardware uses edge triggered interrupt. Do not touch the + * hardware registers in this handler to make sure to catch the next + * interrupt edge. Just send a complete signal and return. + */ + complete(&priv->comp); + + return IRQ_HANDLED; +} + +static int uniphier_i2c_xfer_byte(struct i2c_adapter *adap, u32 txdata, + u32 *rxdatap) +{ + struct uniphier_i2c_priv *priv = i2c_get_adapdata(adap); + unsigned long time_left; + u32 rxdata; + + reinit_completion(&priv->comp); + + txdata |= UNIPHIER_I2C_DTRM_IRQEN; + dev_dbg(&adap->dev, "write data: 0x%04x\n", txdata); + writel(txdata, priv->membase + UNIPHIER_I2C_DTRM); + + time_left = wait_for_completion_timeout(&priv->comp, adap->timeout); + if (unlikely(!time_left)) { + dev_err(&adap->dev, "transaction timeout\n"); + return -ETIMEDOUT; + } + + rxdata = readl(priv->membase + UNIPHIER_I2C_DREC); + dev_dbg(&adap->dev, "read data: 0x%04x\n", rxdata); + + if (rxdatap) + *rxdatap = rxdata; + + return 0; +} + +static int uniphier_i2c_send_byte(struct i2c_adapter *adap, u32 txdata) +{ + u32 rxdata; + int ret; + + ret = uniphier_i2c_xfer_byte(adap, txdata, &rxdata); + if (ret) + return ret; + + if (unlikely(rxdata & UNIPHIER_I2C_DREC_LAB)) { + dev_dbg(&adap->dev, "arbitration lost\n"); + return -EAGAIN; + } + if (unlikely(rxdata & UNIPHIER_I2C_DREC_LRB)) { + dev_dbg(&adap->dev, "could not get ACK\n"); + return -ENXIO; + } + + return 0; +} + +static int uniphier_i2c_tx(struct i2c_adapter *adap, u16 addr, u16 len, + const u8 *buf) +{ + int ret; + + dev_dbg(&adap->dev, "start condition\n"); + ret = uniphier_i2c_send_byte(adap, addr << 1 | + UNIPHIER_I2C_DTRM_STA | + UNIPHIER_I2C_DTRM_NACK); + if (ret) + return ret; + + while (len--) { + ret = uniphier_i2c_send_byte(adap, + UNIPHIER_I2C_DTRM_NACK | *buf++); + if (ret) + return ret; + } + + return 0; +} + +static int uniphier_i2c_rx(struct i2c_adapter *adap, u16 addr, u16 len, + u8 *buf) +{ + int ret; + + dev_dbg(&adap->dev, "start condition\n"); + ret = uniphier_i2c_send_byte(adap, addr << 1 | + UNIPHIER_I2C_DTRM_STA | + UNIPHIER_I2C_DTRM_NACK | + UNIPHIER_I2C_DTRM_RD); + if (ret) + return ret; + + while (len--) { + u32 rxdata; + + ret = uniphier_i2c_xfer_byte(adap, + len ? 0 : UNIPHIER_I2C_DTRM_NACK, + &rxdata); + if (ret) + return ret; + *buf++ = rxdata; + } + + return 0; +} + +static int uniphier_i2c_stop(struct i2c_adapter *adap) +{ + dev_dbg(&adap->dev, "stop condition\n"); + return uniphier_i2c_send_byte(adap, UNIPHIER_I2C_DTRM_STO | + UNIPHIER_I2C_DTRM_NACK); +} + +static int uniphier_i2c_master_xfer_one(struct i2c_adapter *adap, + struct i2c_msg *msg, bool stop) +{ + bool is_read = msg->flags & I2C_M_RD; + bool recovery = false; + int ret; + + dev_dbg(&adap->dev, "%s: addr=0x%02x, len=%d, stop=%d\n", + is_read ? "receive" : "transmit", msg->addr, msg->len, stop); + + if (is_read) + ret = uniphier_i2c_rx(adap, msg->addr, msg->len, msg->buf); + else + ret = uniphier_i2c_tx(adap, msg->addr, msg->len, msg->buf); + + if (ret == -EAGAIN) /* could not acquire bus. bail out without STOP */ + return ret; + + if (ret == -ETIMEDOUT) { + /* This error is fatal. Needs recovery. */ + stop = false; + recovery = true; + } + + if (stop) { + int ret2 = uniphier_i2c_stop(adap); + + if (ret2) { + /* Failed to issue STOP. The bus needs recovery. */ + recovery = true; + ret = ret ?: ret2; + } + } + + if (recovery) + i2c_recover_bus(adap); + + return ret; +} + +static int uniphier_i2c_check_bus_busy(struct i2c_adapter *adap) +{ + struct uniphier_i2c_priv *priv = i2c_get_adapdata(adap); + + if (!(readl(priv->membase + UNIPHIER_I2C_DREC) & + UNIPHIER_I2C_DREC_BBN)) { + if (priv->busy_cnt++ > 3) { + /* + * If bus busy continues too long, it is probably + * in a wrong state. Try bus recovery. + */ + i2c_recover_bus(adap); + priv->busy_cnt = 0; + } + + return -EAGAIN; + } + + priv->busy_cnt = 0; + return 0; +} + +static int uniphier_i2c_master_xfer(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + struct i2c_msg *msg, *emsg = msgs + num; + int ret; + + ret = uniphier_i2c_check_bus_busy(adap); + if (ret) + return ret; + + for (msg = msgs; msg < emsg; msg++) { + /* If next message is read, skip the stop condition */ + bool stop = !(msg + 1 < emsg && msg[1].flags & I2C_M_RD); + /* but, force it if I2C_M_STOP is set */ + if (msg->flags & I2C_M_STOP) + stop = true; + + ret = uniphier_i2c_master_xfer_one(adap, msg, stop); + if (ret) + return ret; + } + + return num; +} + +static u32 uniphier_i2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm uniphier_i2c_algo = { + .master_xfer = uniphier_i2c_master_xfer, + .functionality = uniphier_i2c_functionality, +}; + +static void uniphier_i2c_reset(struct uniphier_i2c_priv *priv, bool reset_on) +{ + u32 val = UNIPHIER_I2C_BRST_RSCL; + + val |= reset_on ? 0 : UNIPHIER_I2C_BRST_FOEN; + writel(val, priv->membase + UNIPHIER_I2C_BRST); +} + +static int uniphier_i2c_get_scl(struct i2c_adapter *adap) +{ + struct uniphier_i2c_priv *priv = i2c_get_adapdata(adap); + + return !!(readl(priv->membase + UNIPHIER_I2C_BSTS) & + UNIPHIER_I2C_BSTS_SCL); +} + +static void uniphier_i2c_set_scl(struct i2c_adapter *adap, int val) +{ + struct uniphier_i2c_priv *priv = i2c_get_adapdata(adap); + + writel(val ? UNIPHIER_I2C_BRST_RSCL : 0, + priv->membase + UNIPHIER_I2C_BRST); +} + +static int uniphier_i2c_get_sda(struct i2c_adapter *adap) +{ + struct uniphier_i2c_priv *priv = i2c_get_adapdata(adap); + + return !!(readl(priv->membase + UNIPHIER_I2C_BSTS) & + UNIPHIER_I2C_BSTS_SDA); +} + +static void uniphier_i2c_unprepare_recovery(struct i2c_adapter *adap) +{ + uniphier_i2c_reset(i2c_get_adapdata(adap), false); +} + +static struct i2c_bus_recovery_info uniphier_i2c_bus_recovery_info = { + .recover_bus = i2c_generic_scl_recovery, + .get_scl = uniphier_i2c_get_scl, + .set_scl = uniphier_i2c_set_scl, + .get_sda = uniphier_i2c_get_sda, + .unprepare_recovery = uniphier_i2c_unprepare_recovery, +}; + +static int uniphier_i2c_clk_init(struct device *dev, + struct uniphier_i2c_priv *priv) +{ + struct device_node *np = dev->of_node; + unsigned long clk_rate; + u32 bus_speed; + int ret; + + if (of_property_read_u32(np, "clock-frequency", &bus_speed)) + bus_speed = UNIPHIER_I2C_DEFAULT_SPEED; + + if (bus_speed > UNIPHIER_I2C_MAX_SPEED) + bus_speed = UNIPHIER_I2C_MAX_SPEED; + + /* Get input clk rate through clk driver */ + priv->clk = devm_clk_get(dev, NULL); + if (IS_ERR(priv->clk)) { + dev_err(dev, "failed to get clock\n"); + return PTR_ERR(priv->clk); + } + + ret = clk_prepare_enable(priv->clk); + if (ret) + return ret; + + clk_rate = clk_get_rate(priv->clk); + + uniphier_i2c_reset(priv, true); + + writel((clk_rate / bus_speed / 2 << 16) | (clk_rate / bus_speed), + priv->membase + UNIPHIER_I2C_CLK); + + uniphier_i2c_reset(priv, false); + + return 0; +} + +static int uniphier_i2c_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct uniphier_i2c_priv *priv; + struct resource *regs; + int irq; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + priv->membase = devm_ioremap_resource(dev, regs); + if (IS_ERR(priv->membase)) + return PTR_ERR(priv->membase); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(dev, "failed to get IRQ number"); + return irq; + } + + init_completion(&priv->comp); + priv->adap.owner = THIS_MODULE; + priv->adap.algo = &uniphier_i2c_algo; + priv->adap.dev.parent = dev; + priv->adap.dev.of_node = dev->of_node; + strlcpy(priv->adap.name, "UniPhier I2C", sizeof(priv->adap.name)); + priv->adap.bus_recovery_info = &uniphier_i2c_bus_recovery_info; + i2c_set_adapdata(&priv->adap, priv); + platform_set_drvdata(pdev, priv); + + ret = uniphier_i2c_clk_init(dev, priv); + if (ret) + return ret; + + ret = devm_request_irq(dev, irq, uniphier_i2c_interrupt, 0, pdev->name, + priv); + if (ret) { + dev_err(dev, "failed to request irq %d\n", irq); + goto err; + } + + ret = i2c_add_adapter(&priv->adap); + if (ret) { + dev_err(dev, "failed to add I2C adapter\n"); + goto err; + } + +err: + if (ret) + clk_disable_unprepare(priv->clk); + + return ret; +} + +static int uniphier_i2c_remove(struct platform_device *pdev) +{ + struct uniphier_i2c_priv *priv = platform_get_drvdata(pdev); + + i2c_del_adapter(&priv->adap); + clk_disable_unprepare(priv->clk); + + return 0; +} + +static const struct of_device_id uniphier_i2c_match[] = { + { .compatible = "socionext,uniphier-i2c" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, uniphier_i2c_match); + +static struct platform_driver uniphier_i2c_drv = { + .probe = uniphier_i2c_probe, + .remove = uniphier_i2c_remove, + .driver = { + .name = "uniphier-i2c", + .of_match_table = uniphier_i2c_match, + }, +}; +module_platform_driver(uniphier_i2c_drv); + +MODULE_AUTHOR("Masahiro Yamada "); +MODULE_DESCRIPTION("UniPhier I2C bus driver"); +MODULE_LICENSE("GPL"); -- cgit v1.2.3 From 6a62974b667f3976ec44e255bed31746cca1ff51 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Fri, 23 Oct 2015 19:52:00 +0900 Subject: i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver Add support for on-chip I2C controller used on newer UniPhier SoCs such as PH1-Pro4, PH1-Pro5, etc. This adapter is equipped with 8-depth TX/RX FIFOs. Signed-off-by: Masahiro Yamada Signed-off-by: Wolfram Sang --- .../devicetree/bindings/i2c/i2c-uniphier-f.txt | 25 + drivers/i2c/busses/Kconfig | 8 + drivers/i2c/busses/Makefile | 1 + drivers/i2c/busses/i2c-uniphier-f.c | 584 +++++++++++++++++++++ 4 files changed, 618 insertions(+) create mode 100644 Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt create mode 100644 drivers/i2c/busses/i2c-uniphier-f.c (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt b/Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt new file mode 100644 index 000000000000..27fc6f8c798b --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt @@ -0,0 +1,25 @@ +UniPhier I2C controller (FIFO-builtin) + +Required properties: +- compatible: should be "socionext,uniphier-fi2c". +- #address-cells: should be 1. +- #size-cells: should be 0. +- reg: offset and length of the register set for the device. +- interrupts: a single interrupt specifier. +- clocks: phandle to the input clock. + +Optional properties: +- clock-frequency: desired I2C bus frequency in Hz. The maximum supported + value is 400000. Defaults to 100000 if not specified. + +Examples: + + i2c0: i2c@58780000 { + compatible = "socionext,uniphier-fi2c"; + reg = <0x58780000 0x80>; + #address-cells = <1>; + #size-cells = <0>; + interrupts = <0 41 4>; + clocks = <&i2c_clk>; + clock-frequency = <100000>; + }; diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 6a40e1693dd4..0774f18f5716 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -910,6 +910,14 @@ config I2C_UNIPHIER the UniPhier FIFO-less I2C interface embedded in PH1-LD4, PH1-sLD8, or older UniPhier SoCs. +config I2C_UNIPHIER_F + tristate "UniPhier FIFO-builtin I2C controller" + depends on ARCH_UNIPHIER + help + If you say yes to this option, support will be included for + the UniPhier FIFO-builtin I2C interface embedded in PH1-Pro4, + PH1-Pro5, or newer UniPhier SoCs. + config I2C_VERSATILE tristate "ARM Versatile/Realview I2C bus support" depends on ARCH_VERSATILE || ARCH_REALVIEW || ARCH_VEXPRESS diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index f9f090285681..37f2819b4560 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -88,6 +88,7 @@ obj-$(CONFIG_I2C_STU300) += i2c-stu300.o obj-$(CONFIG_I2C_SUN6I_P2WI) += i2c-sun6i-p2wi.o obj-$(CONFIG_I2C_TEGRA) += i2c-tegra.o obj-$(CONFIG_I2C_UNIPHIER) += i2c-uniphier.o +obj-$(CONFIG_I2C_UNIPHIER_F) += i2c-uniphier-f.o obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o obj-$(CONFIG_I2C_WMT) += i2c-wmt.o obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o diff --git a/drivers/i2c/busses/i2c-uniphier-f.c b/drivers/i2c/busses/i2c-uniphier-f.c new file mode 100644 index 000000000000..e8d03bcfe3e0 --- /dev/null +++ b/drivers/i2c/busses/i2c-uniphier-f.c @@ -0,0 +1,584 @@ +/* + * Copyright (C) 2015 Masahiro Yamada + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include +#include + +#define UNIPHIER_FI2C_CR 0x00 /* control register */ +#define UNIPHIER_FI2C_CR_MST BIT(3) /* master mode */ +#define UNIPHIER_FI2C_CR_STA BIT(2) /* start condition */ +#define UNIPHIER_FI2C_CR_STO BIT(1) /* stop condition */ +#define UNIPHIER_FI2C_CR_NACK BIT(0) /* do not return ACK */ +#define UNIPHIER_FI2C_DTTX 0x04 /* TX FIFO */ +#define UNIPHIER_FI2C_DTTX_CMD BIT(8) /* send command (slave addr) */ +#define UNIPHIER_FI2C_DTTX_RD BIT(0) /* read transaction */ +#define UNIPHIER_FI2C_DTRX 0x04 /* RX FIFO */ +#define UNIPHIER_FI2C_SLAD 0x0c /* slave address */ +#define UNIPHIER_FI2C_CYC 0x10 /* clock cycle control */ +#define UNIPHIER_FI2C_LCTL 0x14 /* clock low period control */ +#define UNIPHIER_FI2C_SSUT 0x18 /* restart/stop setup time control */ +#define UNIPHIER_FI2C_DSUT 0x1c /* data setup time control */ +#define UNIPHIER_FI2C_INT 0x20 /* interrupt status */ +#define UNIPHIER_FI2C_IE 0x24 /* interrupt enable */ +#define UNIPHIER_FI2C_IC 0x28 /* interrupt clear */ +#define UNIPHIER_FI2C_INT_TE BIT(9) /* TX FIFO empty */ +#define UNIPHIER_FI2C_INT_RF BIT(8) /* RX FIFO full */ +#define UNIPHIER_FI2C_INT_TC BIT(7) /* send complete (STOP) */ +#define UNIPHIER_FI2C_INT_RC BIT(6) /* receive complete (STOP) */ +#define UNIPHIER_FI2C_INT_TB BIT(5) /* sent specified bytes */ +#define UNIPHIER_FI2C_INT_RB BIT(4) /* received specified bytes */ +#define UNIPHIER_FI2C_INT_NA BIT(2) /* no ACK */ +#define UNIPHIER_FI2C_INT_AL BIT(1) /* arbitration lost */ +#define UNIPHIER_FI2C_SR 0x2c /* status register */ +#define UNIPHIER_FI2C_SR_DB BIT(12) /* device busy */ +#define UNIPHIER_FI2C_SR_STS BIT(11) /* stop condition detected */ +#define UNIPHIER_FI2C_SR_BB BIT(8) /* bus busy */ +#define UNIPHIER_FI2C_SR_RFF BIT(3) /* RX FIFO full */ +#define UNIPHIER_FI2C_SR_RNE BIT(2) /* RX FIFO not empty */ +#define UNIPHIER_FI2C_SR_TNF BIT(1) /* TX FIFO not full */ +#define UNIPHIER_FI2C_SR_TFE BIT(0) /* TX FIFO empty */ +#define UNIPHIER_FI2C_RST 0x34 /* reset control */ +#define UNIPHIER_FI2C_RST_TBRST BIT(2) /* clear TX FIFO */ +#define UNIPHIER_FI2C_RST_RBRST BIT(1) /* clear RX FIFO */ +#define UNIPHIER_FI2C_RST_RST BIT(0) /* forcible bus reset */ +#define UNIPHIER_FI2C_BM 0x38 /* bus monitor */ +#define UNIPHIER_FI2C_BM_SDAO BIT(3) /* output for SDA line */ +#define UNIPHIER_FI2C_BM_SDAS BIT(2) /* readback of SDA line */ +#define UNIPHIER_FI2C_BM_SCLO BIT(1) /* output for SCL line */ +#define UNIPHIER_FI2C_BM_SCLS BIT(0) /* readback of SCL line */ +#define UNIPHIER_FI2C_NOISE 0x3c /* noise filter control */ +#define UNIPHIER_FI2C_TBC 0x40 /* TX byte count setting */ +#define UNIPHIER_FI2C_RBC 0x44 /* RX byte count setting */ +#define UNIPHIER_FI2C_TBCM 0x48 /* TX byte count monitor */ +#define UNIPHIER_FI2C_RBCM 0x4c /* RX byte count monitor */ +#define UNIPHIER_FI2C_BRST 0x50 /* bus reset */ +#define UNIPHIER_FI2C_BRST_FOEN BIT(1) /* normal operation */ +#define UNIPHIER_FI2C_BRST_RSCL BIT(0) /* release SCL */ + +#define UNIPHIER_FI2C_INT_FAULTS \ + (UNIPHIER_FI2C_INT_NA | UNIPHIER_FI2C_INT_AL) +#define UNIPHIER_FI2C_INT_STOP \ + (UNIPHIER_FI2C_INT_TC | UNIPHIER_FI2C_INT_RC) + +#define UNIPHIER_FI2C_RD BIT(0) +#define UNIPHIER_FI2C_STOP BIT(1) +#define UNIPHIER_FI2C_MANUAL_NACK BIT(2) +#define UNIPHIER_FI2C_BYTE_WISE BIT(3) +#define UNIPHIER_FI2C_DEFER_STOP_COMP BIT(4) + +#define UNIPHIER_FI2C_DEFAULT_SPEED 100000 +#define UNIPHIER_FI2C_MAX_SPEED 400000 +#define UNIPHIER_FI2C_FIFO_SIZE 8 + +struct uniphier_fi2c_priv { + struct completion comp; + struct i2c_adapter adap; + void __iomem *membase; + struct clk *clk; + unsigned int len; + u8 *buf; + u32 enabled_irqs; + int error; + unsigned int flags; + unsigned int busy_cnt; +}; + +static void uniphier_fi2c_fill_txfifo(struct uniphier_fi2c_priv *priv, + bool first) +{ + int fifo_space = UNIPHIER_FI2C_FIFO_SIZE; + + /* + * TX-FIFO stores slave address in it for the first access. + * Decrement the counter. + */ + if (first) + fifo_space--; + + while (priv->len) { + if (fifo_space-- <= 0) + break; + + dev_dbg(&priv->adap.dev, "write data: %02x\n", *priv->buf); + writel(*priv->buf++, priv->membase + UNIPHIER_FI2C_DTTX); + priv->len--; + } +} + +static void uniphier_fi2c_drain_rxfifo(struct uniphier_fi2c_priv *priv) +{ + int fifo_left = priv->flags & UNIPHIER_FI2C_BYTE_WISE ? + 1 : UNIPHIER_FI2C_FIFO_SIZE; + + while (priv->len) { + if (fifo_left-- <= 0) + break; + + *priv->buf++ = readl(priv->membase + UNIPHIER_FI2C_DTRX); + dev_dbg(&priv->adap.dev, "read data: %02x\n", priv->buf[-1]); + priv->len--; + } +} + +static void uniphier_fi2c_set_irqs(struct uniphier_fi2c_priv *priv) +{ + writel(priv->enabled_irqs, priv->membase + UNIPHIER_FI2C_IE); +} + +static void uniphier_fi2c_clear_irqs(struct uniphier_fi2c_priv *priv) +{ + writel(-1, priv->membase + UNIPHIER_FI2C_IC); +} + +static void uniphier_fi2c_stop(struct uniphier_fi2c_priv *priv) +{ + dev_dbg(&priv->adap.dev, "stop condition\n"); + + priv->enabled_irqs |= UNIPHIER_FI2C_INT_STOP; + uniphier_fi2c_set_irqs(priv); + writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STO, + priv->membase + UNIPHIER_FI2C_CR); +} + +static irqreturn_t uniphier_fi2c_interrupt(int irq, void *dev_id) +{ + struct uniphier_fi2c_priv *priv = dev_id; + u32 irq_status; + + irq_status = readl(priv->membase + UNIPHIER_FI2C_INT); + + dev_dbg(&priv->adap.dev, + "interrupt: enabled_irqs=%04x, irq_status=%04x\n", + priv->enabled_irqs, irq_status); + + if (irq_status & UNIPHIER_FI2C_INT_STOP) + goto complete; + + if (unlikely(irq_status & UNIPHIER_FI2C_INT_AL)) { + dev_dbg(&priv->adap.dev, "arbitration lost\n"); + priv->error = -EAGAIN; + goto complete; + } + + if (unlikely(irq_status & UNIPHIER_FI2C_INT_NA)) { + dev_dbg(&priv->adap.dev, "could not get ACK\n"); + priv->error = -ENXIO; + if (priv->flags & UNIPHIER_FI2C_RD) { + /* + * work around a hardware bug: + * The receive-completed interrupt is never set even if + * STOP condition is detected after the address phase + * of read transaction fails to get ACK. + * To avoid time-out error, we issue STOP here, + * but do not wait for its completion. + * It should be checked after exiting this handler. + */ + uniphier_fi2c_stop(priv); + priv->flags |= UNIPHIER_FI2C_DEFER_STOP_COMP; + goto complete; + } + goto stop; + } + + if (irq_status & UNIPHIER_FI2C_INT_TE) { + if (!priv->len) + goto data_done; + + uniphier_fi2c_fill_txfifo(priv, false); + goto handled; + } + + if (irq_status & (UNIPHIER_FI2C_INT_RF | UNIPHIER_FI2C_INT_RB)) { + uniphier_fi2c_drain_rxfifo(priv); + if (!priv->len) + goto data_done; + + if (unlikely(priv->flags & UNIPHIER_FI2C_MANUAL_NACK)) { + if (priv->len <= UNIPHIER_FI2C_FIFO_SIZE && + !(priv->flags & UNIPHIER_FI2C_BYTE_WISE)) { + dev_dbg(&priv->adap.dev, + "enable read byte count IRQ\n"); + priv->enabled_irqs |= UNIPHIER_FI2C_INT_RB; + uniphier_fi2c_set_irqs(priv); + priv->flags |= UNIPHIER_FI2C_BYTE_WISE; + } + if (priv->len <= 1) { + dev_dbg(&priv->adap.dev, "set NACK\n"); + writel(UNIPHIER_FI2C_CR_MST | + UNIPHIER_FI2C_CR_NACK, + priv->membase + UNIPHIER_FI2C_CR); + } + } + + goto handled; + } + + return IRQ_NONE; + +data_done: + if (priv->flags & UNIPHIER_FI2C_STOP) { +stop: + uniphier_fi2c_stop(priv); + } else { +complete: + priv->enabled_irqs = 0; + uniphier_fi2c_set_irqs(priv); + complete(&priv->comp); + } + +handled: + uniphier_fi2c_clear_irqs(priv); + + return IRQ_HANDLED; +} + +static void uniphier_fi2c_tx_init(struct uniphier_fi2c_priv *priv, u16 addr) +{ + priv->enabled_irqs |= UNIPHIER_FI2C_INT_TE; + /* do not use TX byte counter */ + writel(0, priv->membase + UNIPHIER_FI2C_TBC); + /* set slave address */ + writel(UNIPHIER_FI2C_DTTX_CMD | addr << 1, + priv->membase + UNIPHIER_FI2C_DTTX); + /* first chunk of data */ + uniphier_fi2c_fill_txfifo(priv, true); +} + +static void uniphier_fi2c_rx_init(struct uniphier_fi2c_priv *priv, u16 addr) +{ + priv->flags |= UNIPHIER_FI2C_RD; + + if (likely(priv->len < 256)) { + /* + * If possible, use RX byte counter. + * It can automatically handle NACK for the last byte. + */ + writel(priv->len, priv->membase + UNIPHIER_FI2C_RBC); + priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF | + UNIPHIER_FI2C_INT_RB; + } else { + /* + * The byte counter can not count over 256. In this case, + * do not use it at all. Drain data when FIFO gets full, + * but treat the last portion as a special case. + */ + writel(0, priv->membase + UNIPHIER_FI2C_RBC); + priv->flags |= UNIPHIER_FI2C_MANUAL_NACK; + priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF; + } + + /* set slave address with RD bit */ + writel(UNIPHIER_FI2C_DTTX_CMD | UNIPHIER_FI2C_DTTX_RD | addr << 1, + priv->membase + UNIPHIER_FI2C_DTTX); +} + +static void uniphier_fi2c_reset(struct uniphier_fi2c_priv *priv) +{ + writel(UNIPHIER_FI2C_RST_RST, priv->membase + UNIPHIER_FI2C_RST); +} + +static void uniphier_fi2c_prepare_operation(struct uniphier_fi2c_priv *priv) +{ + writel(UNIPHIER_FI2C_BRST_FOEN | UNIPHIER_FI2C_BRST_RSCL, + priv->membase + UNIPHIER_FI2C_BRST); +} + +static void uniphier_fi2c_recover(struct uniphier_fi2c_priv *priv) +{ + uniphier_fi2c_reset(priv); + i2c_recover_bus(&priv->adap); +} + +static int uniphier_fi2c_master_xfer_one(struct i2c_adapter *adap, + struct i2c_msg *msg, bool stop) +{ + struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); + bool is_read = msg->flags & I2C_M_RD; + unsigned long time_left; + + dev_dbg(&adap->dev, "%s: addr=0x%02x, len=%d, stop=%d\n", + is_read ? "receive" : "transmit", msg->addr, msg->len, stop); + + priv->len = msg->len; + priv->buf = msg->buf; + priv->enabled_irqs = UNIPHIER_FI2C_INT_FAULTS; + priv->error = 0; + priv->flags = 0; + + if (stop) + priv->flags |= UNIPHIER_FI2C_STOP; + + reinit_completion(&priv->comp); + uniphier_fi2c_clear_irqs(priv); + writel(UNIPHIER_FI2C_RST_TBRST | UNIPHIER_FI2C_RST_RBRST, + priv->membase + UNIPHIER_FI2C_RST); /* reset TX/RX FIFO */ + + if (is_read) + uniphier_fi2c_rx_init(priv, msg->addr); + else + uniphier_fi2c_tx_init(priv, msg->addr); + + uniphier_fi2c_set_irqs(priv); + + dev_dbg(&adap->dev, "start condition\n"); + writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STA, + priv->membase + UNIPHIER_FI2C_CR); + + time_left = wait_for_completion_timeout(&priv->comp, adap->timeout); + if (!time_left) { + dev_err(&adap->dev, "transaction timeout.\n"); + uniphier_fi2c_recover(priv); + return -ETIMEDOUT; + } + dev_dbg(&adap->dev, "complete\n"); + + if (unlikely(priv->flags & UNIPHIER_FI2C_DEFER_STOP_COMP)) { + u32 status = readl(priv->membase + UNIPHIER_FI2C_SR); + + if (!(status & UNIPHIER_FI2C_SR_STS) || + status & UNIPHIER_FI2C_SR_BB) { + dev_err(&adap->dev, + "stop condition was not completed.\n"); + uniphier_fi2c_recover(priv); + return -EBUSY; + } + } + + return priv->error; +} + +static int uniphier_fi2c_check_bus_busy(struct i2c_adapter *adap) +{ + struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); + + if (readl(priv->membase + UNIPHIER_FI2C_SR) & UNIPHIER_FI2C_SR_DB) { + if (priv->busy_cnt++ > 3) { + /* + * If bus busy continues too long, it is probably + * in a wrong state. Try bus recovery. + */ + uniphier_fi2c_recover(priv); + priv->busy_cnt = 0; + } + + return -EAGAIN; + } + + priv->busy_cnt = 0; + return 0; +} + +static int uniphier_fi2c_master_xfer(struct i2c_adapter *adap, + struct i2c_msg *msgs, int num) +{ + struct i2c_msg *msg, *emsg = msgs + num; + int ret; + + ret = uniphier_fi2c_check_bus_busy(adap); + if (ret) + return ret; + + for (msg = msgs; msg < emsg; msg++) { + /* If next message is read, skip the stop condition */ + bool stop = !(msg + 1 < emsg && msg[1].flags & I2C_M_RD); + /* but, force it if I2C_M_STOP is set */ + if (msg->flags & I2C_M_STOP) + stop = true; + + ret = uniphier_fi2c_master_xfer_one(adap, msg, stop); + if (ret) + return ret; + } + + return num; +} + +static u32 uniphier_fi2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm uniphier_fi2c_algo = { + .master_xfer = uniphier_fi2c_master_xfer, + .functionality = uniphier_fi2c_functionality, +}; + +static int uniphier_fi2c_get_scl(struct i2c_adapter *adap) +{ + struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); + + return !!(readl(priv->membase + UNIPHIER_FI2C_BM) & + UNIPHIER_FI2C_BM_SCLS); +} + +static void uniphier_fi2c_set_scl(struct i2c_adapter *adap, int val) +{ + struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); + + writel(val ? UNIPHIER_FI2C_BRST_RSCL : 0, + priv->membase + UNIPHIER_FI2C_BRST); +} + +static int uniphier_fi2c_get_sda(struct i2c_adapter *adap) +{ + struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap); + + return !!(readl(priv->membase + UNIPHIER_FI2C_BM) & + UNIPHIER_FI2C_BM_SDAS); +} + +static void uniphier_fi2c_unprepare_recovery(struct i2c_adapter *adap) +{ + uniphier_fi2c_prepare_operation(i2c_get_adapdata(adap)); +} + +static struct i2c_bus_recovery_info uniphier_fi2c_bus_recovery_info = { + .recover_bus = i2c_generic_scl_recovery, + .get_scl = uniphier_fi2c_get_scl, + .set_scl = uniphier_fi2c_set_scl, + .get_sda = uniphier_fi2c_get_sda, + .unprepare_recovery = uniphier_fi2c_unprepare_recovery, +}; + +static int uniphier_fi2c_clk_init(struct device *dev, + struct uniphier_fi2c_priv *priv) +{ + struct device_node *np = dev->of_node; + unsigned long clk_rate; + u32 bus_speed, clk_count; + int ret; + + if (of_property_read_u32(np, "clock-frequency", &bus_speed)) + bus_speed = UNIPHIER_FI2C_DEFAULT_SPEED; + + if (bus_speed > UNIPHIER_FI2C_MAX_SPEED) + bus_speed = UNIPHIER_FI2C_MAX_SPEED; + + /* Get input clk rate through clk driver */ + priv->clk = devm_clk_get(dev, NULL); + if (IS_ERR(priv->clk)) { + dev_err(dev, "failed to get clock\n"); + return PTR_ERR(priv->clk); + } + + ret = clk_prepare_enable(priv->clk); + if (ret) + return ret; + + clk_rate = clk_get_rate(priv->clk); + + uniphier_fi2c_reset(priv); + + clk_count = clk_rate / bus_speed; + + writel(clk_count, priv->membase + UNIPHIER_FI2C_CYC); + writel(clk_count / 2, priv->membase + UNIPHIER_FI2C_LCTL); + writel(clk_count / 2, priv->membase + UNIPHIER_FI2C_SSUT); + writel(clk_count / 16, priv->membase + UNIPHIER_FI2C_DSUT); + + uniphier_fi2c_prepare_operation(priv); + + return 0; +} + +static int uniphier_fi2c_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct uniphier_fi2c_priv *priv; + struct resource *regs; + int irq; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + priv->membase = devm_ioremap_resource(dev, regs); + if (IS_ERR(priv->membase)) + return PTR_ERR(priv->membase); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(dev, "failed to get IRQ number"); + return irq; + } + + init_completion(&priv->comp); + priv->adap.owner = THIS_MODULE; + priv->adap.algo = &uniphier_fi2c_algo; + priv->adap.dev.parent = dev; + priv->adap.dev.of_node = dev->of_node; + strlcpy(priv->adap.name, "UniPhier FI2C", sizeof(priv->adap.name)); + priv->adap.bus_recovery_info = &uniphier_fi2c_bus_recovery_info; + i2c_set_adapdata(&priv->adap, priv); + platform_set_drvdata(pdev, priv); + + ret = uniphier_fi2c_clk_init(dev, priv); + if (ret) + return ret; + + ret = devm_request_irq(dev, irq, uniphier_fi2c_interrupt, 0, + pdev->name, priv); + if (ret) { + dev_err(dev, "failed to request irq %d\n", irq); + goto err; + } + + ret = i2c_add_adapter(&priv->adap); + if (ret) { + dev_err(dev, "failed to add I2C adapter\n"); + goto err; + } + +err: + if (ret) + clk_disable_unprepare(priv->clk); + + return ret; +} + +static int uniphier_fi2c_remove(struct platform_device *pdev) +{ + struct uniphier_fi2c_priv *priv = platform_get_drvdata(pdev); + + i2c_del_adapter(&priv->adap); + clk_disable_unprepare(priv->clk); + + return 0; +} + +static const struct of_device_id uniphier_fi2c_match[] = { + { .compatible = "socionext,uniphier-fi2c" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, uniphier_fi2c_match); + +static struct platform_driver uniphier_fi2c_drv = { + .probe = uniphier_fi2c_probe, + .remove = uniphier_fi2c_remove, + .driver = { + .name = "uniphier-fi2c", + .of_match_table = uniphier_fi2c_match, + }, +}; +module_platform_driver(uniphier_fi2c_drv); + +MODULE_AUTHOR("Masahiro Yamada "); +MODULE_DESCRIPTION("UniPhier FIFO-builtin I2C bus driver"); +MODULE_LICENSE("GPL"); -- cgit v1.2.3 From 1c4b6c3bcf30d0804db0d0647d8ebeb862c6f7e5 Mon Sep 17 00:00:00 2001 From: Gao Pan Date: Fri, 23 Oct 2015 20:28:54 +0800 Subject: i2c: imx: implement bus recovery Implement bus recovery methods for i2c-imx so we can recover from situations where SCL/SDA are stuck low. Once i2c bus SCL/SDA are stuck low during transfer, config the i2c pinctrl to gpio mode by calling pinctrl sleep set function, and then use GPIO to emulate the i2c protocol to send nine dummy clock to recover i2c device. After recovery, set i2c pinctrl to default group setting. Signed-off-by: Fugang Duan Signed-off-by: Gao Pan Signed-off-by: Sascha Hauer Signed-off-by: Wolfram Sang --- Documentation/devicetree/bindings/i2c/i2c-imx.txt | 9 +++ drivers/i2c/busses/i2c-imx.c | 71 +++++++++++++++++++++++ 2 files changed, 80 insertions(+) (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx.txt b/Documentation/devicetree/bindings/i2c/i2c-imx.txt index ce4311d726ae..eab5836ba7f9 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-imx.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-imx.txt @@ -14,6 +14,10 @@ Optional properties: The absence of the propoerty indicates the default frequency 100 kHz. - dmas: A list of two dma specifiers, one for each entry in dma-names. - dma-names: should contain "tx" and "rx". +- scl-gpios: specify the gpio related to SCL pin +- sda-gpios: specify the gpio related to SDA pin +- pinctrl: add extra pinctrl to configure i2c pins to gpio function for i2c + bus recovery, call it "gpio" state Examples: @@ -37,4 +41,9 @@ i2c0: i2c@40066000 { /* i2c0 on vf610 */ dmas = <&edma0 0 50>, <&edma0 0 51>; dma-names = "rx","tx"; + pinctrl-names = "default", "gpio"; + pinctrl-0 = <&pinctrl_i2c1>; + pinctrl-1 = <&pinctrl_i2c1_gpio>; + scl-gpios = <&gpio5 26 GPIO_ACTIVE_HIGH>; + sda-gpios = <&gpio5 27 GPIO_ACTIVE_HIGH>; }; diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 785aa674a4da..8d46e74c720a 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -49,6 +49,7 @@ #include #include #include +#include #include #include #include @@ -207,6 +208,11 @@ struct imx_i2c_struct { unsigned int cur_clk; unsigned int bitrate; const struct imx_i2c_hwdata *hwdata; + struct i2c_bus_recovery_info rinfo; + + struct pinctrl *pinctrl; + struct pinctrl_state *pinctrl_pins_default; + struct pinctrl_state *pinctrl_pins_gpio; struct imx_i2c_dma *dma; }; @@ -896,6 +902,13 @@ static int i2c_imx_xfer(struct i2c_adapter *adapter, /* Start I2C transfer */ result = i2c_imx_start(i2c_imx); + if (result) { + if (i2c_imx->adapter.bus_recovery_info) { + i2c_recover_bus(&i2c_imx->adapter); + result = i2c_imx_start(i2c_imx); + } + } + if (result) goto fail0; @@ -956,6 +969,55 @@ fail0: return (result < 0) ? result : num; } +static void i2c_imx_prepare_recovery(struct i2c_adapter *adap) +{ + struct imx_i2c_struct *i2c_imx; + + i2c_imx = container_of(adap, struct imx_i2c_struct, adapter); + + pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_gpio); +} + +static void i2c_imx_unprepare_recovery(struct i2c_adapter *adap) +{ + struct imx_i2c_struct *i2c_imx; + + i2c_imx = container_of(adap, struct imx_i2c_struct, adapter); + + pinctrl_select_state(i2c_imx->pinctrl, i2c_imx->pinctrl_pins_default); +} + +static void i2c_imx_init_recovery_info(struct imx_i2c_struct *i2c_imx, + struct platform_device *pdev) +{ + struct i2c_bus_recovery_info *rinfo = &i2c_imx->rinfo; + + i2c_imx->pinctrl_pins_default = pinctrl_lookup_state(i2c_imx->pinctrl, + PINCTRL_STATE_DEFAULT); + i2c_imx->pinctrl_pins_gpio = pinctrl_lookup_state(i2c_imx->pinctrl, + "gpio"); + rinfo->sda_gpio = of_get_named_gpio_flags(pdev->dev.of_node, + "sda-gpios", 0, NULL); + rinfo->scl_gpio = of_get_named_gpio_flags(pdev->dev.of_node, + "scl-gpios", 0, NULL); + + if (!gpio_is_valid(rinfo->sda_gpio) || + !gpio_is_valid(rinfo->scl_gpio) || + IS_ERR(i2c_imx->pinctrl_pins_default) || + IS_ERR(i2c_imx->pinctrl_pins_gpio)) { + dev_dbg(&pdev->dev, "recovery information incomplete\n"); + return; + } + + dev_dbg(&pdev->dev, "using scl-gpio %d and sda-gpio %d for recovery\n", + rinfo->sda_gpio, rinfo->scl_gpio); + + rinfo->prepare_recovery = i2c_imx_prepare_recovery; + rinfo->unprepare_recovery = i2c_imx_unprepare_recovery; + rinfo->recover_bus = i2c_generic_gpio_recovery; + i2c_imx->adapter.bus_recovery_info = rinfo; +} + static u32 i2c_imx_func(struct i2c_adapter *adapter) { return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL @@ -1023,6 +1085,13 @@ static int i2c_imx_probe(struct platform_device *pdev) dev_err(&pdev->dev, "can't enable I2C clock\n"); return ret; } + + i2c_imx->pinctrl = devm_pinctrl_get(&pdev->dev); + if (IS_ERR(i2c_imx->pinctrl)) { + ret = PTR_ERR(i2c_imx->pinctrl); + goto clk_disable; + } + /* Request IRQ */ ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, 0, pdev->name, i2c_imx); @@ -1056,6 +1125,8 @@ static int i2c_imx_probe(struct platform_device *pdev) goto clk_disable; } + i2c_imx_init_recovery_info(i2c_imx, pdev); + /* Set up platform driver data */ platform_set_drvdata(pdev, i2c_imx); clk_disable_unprepare(i2c_imx->clk); -- cgit v1.2.3