* [PATCH 1/3] i2c: uniphier: add UniPhier FIFO-less I2C driver
2015-07-30 8:12 [PATCH 0/3] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform Masahiro Yamada
@ 2015-07-30 8:12 ` Masahiro Yamada
2015-10-22 20:59 ` Wolfram Sang
2015-07-30 8:12 ` [PATCH 2/3] i2c: uniphier_f: add UniPhier FIFO-builtin " Masahiro Yamada
` (2 subsequent siblings)
3 siblings, 1 reply; 11+ messages in thread
From: Masahiro Yamada @ 2015-07-30 8:12 UTC (permalink / raw)
To: linux-i2c
Cc: Masahiro Yamada, Mika Westerberg, Anders Berg, Max Schwarz,
David Box, Wei Yan, Zubair Lutfullah Kakakhel, Andrew Bresticker,
Wolfram Sang, linux-kernel, Kamal Dasu, Laurentiu Palcu,
Baruch Siach, Xudong Chen, Lee Jones, Geert Uytterhoeven,
Neelesh Gupta, Sachin Kamat, Ray Jui, linux-arm-kernel
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 <yamada.masahiro@socionext.com>
---
drivers/i2c/busses/Kconfig | 8 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-uniphier.c | 446 ++++++++++++++++++++++++++++++++++++++
3 files changed, 455 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-uniphier.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 577d58d..7073a19 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -885,6 +885,14 @@ 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 e5f537c..e89969c 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -85,6 +85,7 @@ 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 0000000..bd9877f
--- /dev/null
+++ b/drivers/i2c/busses/i2c-uniphier.c
@@ -0,0 +1,446 @@
+/*
+ * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * 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 <linux/clk.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#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;
+}
+
+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);
+ if (!regs) {
+ dev_err(dev, "failed to get memory resource");
+ return -EINVAL;
+ }
+
+ 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_DESCRIPTION("UniPhier I2C bus driver");
+MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
+MODULE_LICENSE("GPL");
--
1.9.1
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH 1/3] i2c: uniphier: add UniPhier FIFO-less I2C driver
2015-07-30 8:12 ` [PATCH 1/3] i2c: uniphier: add UniPhier FIFO-less I2C driver Masahiro Yamada
@ 2015-10-22 20:59 ` Wolfram Sang
2015-10-23 10:52 ` Masahiro Yamada
0 siblings, 1 reply; 11+ messages in thread
From: Wolfram Sang @ 2015-10-22 20:59 UTC (permalink / raw)
To: Masahiro Yamada
Cc: linux-i2c, Mika Westerberg, Anders Berg, Max Schwarz, David Box,
Wei Yan, Zubair Lutfullah Kakakhel, Andrew Bresticker,
linux-kernel, Kamal Dasu, Laurentiu Palcu, Baruch Siach,
Xudong Chen, Lee Jones, Geert Uytterhoeven, Neelesh Gupta,
Sachin Kamat, Ray Jui, linux-arm-kernel
[-- Attachment #1: Type: text/plain, Size: 782 bytes --]
On Thu, Jul 30, 2015 at 05:12:20PM +0900, Masahiro Yamada wrote:
> 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 <yamada.masahiro@socionext.com>
Finally! Mostly looking good.
> +static u32 uniphier_i2c_functionality(struct i2c_adapter *adap)
> +{
> + return I2C_FUNC_I2C;
> +}
No I2C_FUNC_SMBUS_EMUL? But check if SMBUS_QUICK is supported by your
adapter.
> + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!regs) {
> + dev_err(dev, "failed to get memory resource");
> + return -EINVAL;
> + }
This 'if'-block can go. devm_ioremap_resource will check it for you.
Thanks,
Wolfram
[-- Attachment #2: Digital signature --]
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^ permalink raw reply [flat|nested] 11+ messages in thread* Re: [PATCH 1/3] i2c: uniphier: add UniPhier FIFO-less I2C driver
2015-10-22 20:59 ` Wolfram Sang
@ 2015-10-23 10:52 ` Masahiro Yamada
0 siblings, 0 replies; 11+ messages in thread
From: Masahiro Yamada @ 2015-10-23 10:52 UTC (permalink / raw)
To: Wolfram Sang
Cc: linux-i2c, Mika Westerberg, Anders Berg, Max Schwarz, David Box,
Wei Yan, Zubair Lutfullah Kakakhel, Andrew Bresticker,
Linux Kernel Mailing List, Kamal Dasu, Laurentiu Palcu,
Baruch Siach, Xudong Chen, Lee Jones, Geert Uytterhoeven,
Neelesh Gupta, Sachin Kamat, Ray Jui, linux-arm-kernel
Hi Wolfram,
Thanks for your review!
2015-10-23 5:59 GMT+09:00 Wolfram Sang <wsa@the-dreams.de>:
> On Thu, Jul 30, 2015 at 05:12:20PM +0900, Masahiro Yamada wrote:
>> 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 <yamada.masahiro@socionext.com>
>
> Finally! Mostly looking good.
>
>> +static u32 uniphier_i2c_functionality(struct i2c_adapter *adap)
>> +{
>> + return I2C_FUNC_I2C;
>> +}
>
> No I2C_FUNC_SMBUS_EMUL? But check if SMBUS_QUICK is supported by your
> adapter.
Added in v2.
>> + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + if (!regs) {
>> + dev_err(dev, "failed to get memory resource");
>> + return -EINVAL;
>> + }
>
> This 'if'-block can go. devm_ioremap_resource will check it for you.
>
Fixed in v2.
Thanks!
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 2/3] i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver
2015-07-30 8:12 [PATCH 0/3] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform Masahiro Yamada
2015-07-30 8:12 ` [PATCH 1/3] i2c: uniphier: add UniPhier FIFO-less I2C driver Masahiro Yamada
@ 2015-07-30 8:12 ` Masahiro Yamada
2015-10-22 21:06 ` Wolfram Sang
2015-07-30 8:12 ` [PATCH 3/3] i2c: uniphier: add bindings for UniPhier I2C controllers Masahiro Yamada
2015-09-25 2:12 ` [PATCH 0/3] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform Masahiro Yamada
3 siblings, 1 reply; 11+ messages in thread
From: Masahiro Yamada @ 2015-07-30 8:12 UTC (permalink / raw)
To: linux-i2c
Cc: Masahiro Yamada, linux-arm-kernel, Anders Berg, Xudong Chen,
Andrew Bresticker, David Box, Laurentiu Palcu,
Zubair Lutfullah Kakakhel, Kamal Dasu, Wolfram Sang, linux-kernel,
Zhangfei Gao, Beniamino Galvani, Lee Jones, Geert Uytterhoeven,
Neelesh Gupta, Sachin Kamat, Ray Jui, Subhendu Sekhar Behera
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 <yamada.masahiro@socionext.com>
---
drivers/i2c/busses/Kconfig | 8 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-uniphier-f.c | 589 ++++++++++++++++++++++++++++++++++++
3 files changed, 598 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-uniphier-f.c
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 7073a19..5cf2fd5 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -893,6 +893,14 @@ 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 e89969c..6c5bab1 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -86,6 +86,7 @@ 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 0000000..dd7ea6b
--- /dev/null
+++ b/drivers/i2c/busses/i2c-uniphier-f.c
@@ -0,0 +1,589 @@
+/*
+ * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * 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 <linux/clk.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#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 the 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;
+}
+
+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);
+ if (!regs) {
+ dev_err(dev, "failed to get memory resource");
+ return -EINVAL;
+ }
+
+ 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_DESCRIPTION("UniPhier FIFO-builtin I2C bus driver");
+MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
+MODULE_LICENSE("GPL");
--
1.9.1
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH 2/3] i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver
2015-07-30 8:12 ` [PATCH 2/3] i2c: uniphier_f: add UniPhier FIFO-builtin " Masahiro Yamada
@ 2015-10-22 21:06 ` Wolfram Sang
2015-10-23 10:59 ` Masahiro Yamada
0 siblings, 1 reply; 11+ messages in thread
From: Wolfram Sang @ 2015-10-22 21:06 UTC (permalink / raw)
To: Masahiro Yamada
Cc: linux-i2c, linux-arm-kernel, Anders Berg, Xudong Chen,
Andrew Bresticker, David Box, Laurentiu Palcu,
Zubair Lutfullah Kakakhel, Kamal Dasu, linux-kernel, Zhangfei Gao,
Beniamino Galvani, Lee Jones, Geert Uytterhoeven, Neelesh Gupta,
Sachin Kamat, Ray Jui, Subhendu Sekhar Behera
[-- Attachment #1: Type: text/plain, Size: 509 bytes --]
On Thu, Jul 30, 2015 at 05:12:21PM +0900, Masahiro Yamada wrote:
> 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 <yamada.masahiro@socionext.com>
Same comments as for the other driver.
And quite some debug messages left. Could you check if you still want
them or if they were mostly useful during development of the driver?
Thanks,
Wolfram
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^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 2/3] i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver
2015-10-22 21:06 ` Wolfram Sang
@ 2015-10-23 10:59 ` Masahiro Yamada
0 siblings, 0 replies; 11+ messages in thread
From: Masahiro Yamada @ 2015-10-23 10:59 UTC (permalink / raw)
To: Wolfram Sang
Cc: linux-i2c, linux-arm-kernel, Anders Berg, Xudong Chen,
Andrew Bresticker, David Box, Laurentiu Palcu,
Zubair Lutfullah Kakakhel, Kamal Dasu, Linux Kernel Mailing List,
Zhangfei Gao, Beniamino Galvani, Lee Jones, Geert Uytterhoeven,
Neelesh Gupta, Sachin Kamat, Ray Jui, Subhendu Sekhar Behera
2015-10-23 6:06 GMT+09:00 Wolfram Sang <wsa@the-dreams.de>:
> On Thu, Jul 30, 2015 at 05:12:21PM +0900, Masahiro Yamada wrote:
>> 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 <yamada.masahiro@socionext.com>
>
> Same comments as for the other driver.
Fixed in v2.
> And quite some debug messages left. Could you check if you still want
> them or if they were mostly useful during development of the driver?
Yes, I want to keep them. I do not think they are too much.
I will probably come back to these drivers when I find some time
in order to implement further features such as the slave mode. :)
dev_dbg() might be useful for the new development
as well as for checking something when hardware went wrong for some reason.
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 3/3] i2c: uniphier: add bindings for UniPhier I2C controllers
2015-07-30 8:12 [PATCH 0/3] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform Masahiro Yamada
2015-07-30 8:12 ` [PATCH 1/3] i2c: uniphier: add UniPhier FIFO-less I2C driver Masahiro Yamada
2015-07-30 8:12 ` [PATCH 2/3] i2c: uniphier_f: add UniPhier FIFO-builtin " Masahiro Yamada
@ 2015-07-30 8:12 ` Masahiro Yamada
2015-10-22 21:00 ` Wolfram Sang
2015-09-25 2:12 ` [PATCH 0/3] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform Masahiro Yamada
3 siblings, 1 reply; 11+ messages in thread
From: Masahiro Yamada @ 2015-07-30 8:12 UTC (permalink / raw)
To: linux-i2c
Cc: Masahiro Yamada, devicetree, linux-kernel, Wolfram Sang,
Kumar Gala, Ian Campbell, Rob Herring, Pawel Moll, Mark Rutland,
linux-arm-kernel
Device Tree bindings for two I2C controllers embedded in
UniPhier SoCs.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---
.../devicetree/bindings/i2c/i2c-uniphier.txt | 46 ++++++++++++++++++++++
1 file changed, 46 insertions(+)
create mode 100644 Documentation/devicetree/bindings/i2c/i2c-uniphier.txt
diff --git a/Documentation/devicetree/bindings/i2c/i2c-uniphier.txt b/Documentation/devicetree/bindings/i2c/i2c-uniphier.txt
new file mode 100644
index 0000000..e4ddb50
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-uniphier.txt
@@ -0,0 +1,46 @@
+UniPhier I2C controller
+
+Two different types of I2C controller IPs are used on UniPhier SoC platform:
+- FIFO-less I2C controller on PH-LD4, PH1-sLD8 or older SoCs
+- FIFO-builtin I2C controller on PH1-Pro4 or newer SoCs
+
+Required properties:
+- compatible: should be one of the followings:
+ "socionext,uniphier-i2c" (FIFO-less)
+ "socionext,uniphier-fi2c" (FIFO-builtin)
+- #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:
+
+- FIFO-less
+
+ 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>;
+ };
+
+
+- FIFO-builtin
+
+ 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>;
+ };
--
1.9.1
^ permalink raw reply related [flat|nested] 11+ messages in thread* Re: [PATCH 3/3] i2c: uniphier: add bindings for UniPhier I2C controllers
2015-07-30 8:12 ` [PATCH 3/3] i2c: uniphier: add bindings for UniPhier I2C controllers Masahiro Yamada
@ 2015-10-22 21:00 ` Wolfram Sang
2015-10-23 10:54 ` Masahiro Yamada
0 siblings, 1 reply; 11+ messages in thread
From: Wolfram Sang @ 2015-10-22 21:00 UTC (permalink / raw)
To: Masahiro Yamada
Cc: linux-i2c, devicetree, linux-kernel, Kumar Gala, Ian Campbell,
Rob Herring, Pawel Moll, Mark Rutland, linux-arm-kernel
[-- Attachment #1: Type: text/plain, Size: 366 bytes --]
On Thu, Jul 30, 2015 at 05:12:22PM +0900, Masahiro Yamada wrote:
> Device Tree bindings for two I2C controllers embedded in
> UniPhier SoCs.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Please split this into two files with filenames matching those of the
drivers. I know they will be very similar but I'd like to keep
consistent.
[-- Attachment #2: Digital signature --]
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^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 3/3] i2c: uniphier: add bindings for UniPhier I2C controllers
2015-10-22 21:00 ` Wolfram Sang
@ 2015-10-23 10:54 ` Masahiro Yamada
0 siblings, 0 replies; 11+ messages in thread
From: Masahiro Yamada @ 2015-10-23 10:54 UTC (permalink / raw)
To: Wolfram Sang
Cc: linux-i2c, devicetree, Linux Kernel Mailing List, Kumar Gala,
Ian Campbell, Rob Herring, Pawel Moll, Mark Rutland,
linux-arm-kernel
2015-10-23 6:00 GMT+09:00 Wolfram Sang <wsa@the-dreams.de>:
> On Thu, Jul 30, 2015 at 05:12:22PM +0900, Masahiro Yamada wrote:
>> Device Tree bindings for two I2C controllers embedded in
>> UniPhier SoCs.
>>
>> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
>
> Please split this into two files with filenames matching those of the
> drivers. I know they will be very similar but I'd like to keep
> consistent.
>
OK, I splited it in v2.
Each document was merged into the corresponding driver patch.
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 0/3] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform
2015-07-30 8:12 [PATCH 0/3] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform Masahiro Yamada
` (2 preceding siblings ...)
2015-07-30 8:12 ` [PATCH 3/3] i2c: uniphier: add bindings for UniPhier I2C controllers Masahiro Yamada
@ 2015-09-25 2:12 ` Masahiro Yamada
3 siblings, 0 replies; 11+ messages in thread
From: Masahiro Yamada @ 2015-09-25 2:12 UTC (permalink / raw)
To: linux-i2c
Cc: Mark Rutland, Baruch Siach, Wolfram Sang, Andrew Bresticker,
Sachin Kamat, Masahiro Yamada, David Box, Lee Jones, Xudong Chen,
Kamal Dasu, Subhendu Sekhar Behera, Wei Yan, Geert Uytterhoeven,
Neelesh Gupta, Zhangfei Gao, Laurentiu Palcu, devicetree,
Zubair Lutfullah Kakakhel, Pawel Moll, Ian Campbell, Ray Jui,
Beniamino Galvani, Rob Herring, Mika Westerberg, linux-arm-kernel,
Anders Berg, Max Schwarz, Linux Kernel Mailing List, Kumar Gala
Hi Wolfram,
Could you have some time for reviewing this series?
Perhaps, after ELCE?
2015-07-30 17:12 GMT+09:00 Masahiro Yamada <yamada.masahiro@socionext.com>:
>
> This series adds two I2C controller drivers.
> (they are completely different IPs.)
>
> The first one is a very simple FIFO-less I2C controller,
> which is used on some older UniPhier SoCs.
>
> The other one is higher-performance I2C controller with TX/RX FIFO,
> used on newer UniPhier SoCs.
>
>
>
> Masahiro Yamada (3):
> i2c: uniphier: add UniPhier FIFO-less I2C driver
> i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver
> i2c: uniphier: add bindings for UniPhier I2C controllers
>
> .../devicetree/bindings/i2c/i2c-uniphier.txt | 46 ++
> drivers/i2c/busses/Kconfig | 16 +
> drivers/i2c/busses/Makefile | 2 +
> drivers/i2c/busses/i2c-uniphier-f.c | 589 +++++++++++++++++++++
> drivers/i2c/busses/i2c-uniphier.c | 446 ++++++++++++++++
> 5 files changed, 1099 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/i2c/i2c-uniphier.txt
> create mode 100644 drivers/i2c/busses/i2c-uniphier-f.c
> create mode 100644 drivers/i2c/busses/i2c-uniphier.c
>
> --
> 1.9.1
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
--
Best Regards
Masahiro Yamada
^ permalink raw reply [flat|nested] 11+ messages in thread