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openwrt/target/linux/layerscape/patches-4.14/804-i2c-support-layerscape....

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From 3f7d59061c38287bdc2fec2e94b4df9e6e62dbc6 Mon Sep 17 00:00:00 2001
From: Biwen Li <biwen.li@nxp.com>
Date: Wed, 17 Apr 2019 18:58:39 +0800
Subject: [PATCH] i2c: support layerscape
This is an integrated patch of i2c for layerscape
Signed-off-by: Biwen Li <biwen.li@nxp.com>
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Zhang Ying-22455 <ying.zhang22455@nxp.com>
---
drivers/i2c/busses/i2c-imx.c | 245 +++++++++++++++++++++++++---
drivers/i2c/muxes/i2c-mux-pca954x.c | 44 ++++-
2 files changed, 268 insertions(+), 21 deletions(-)
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -53,6 +53,11 @@
#include <linux/pm_runtime.h>
#include <linux/sched.h>
#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/libata.h>
/* This will be the driver name the kernel reports */
#define DRIVER_NAME "imx-i2c"
@@ -117,6 +122,54 @@
#define I2C_PM_TIMEOUT 10 /* ms */
+enum pinmux_endian_type {
+ BIG_ENDIAN,
+ LITTLE_ENDIAN,
+};
+
+struct pinmux_cfg {
+ enum pinmux_endian_type endian; /* endian of RCWPMUXCR0 */
+ u32 pmuxcr_offset;
+ u32 pmuxcr_set_bit; /* pin mux of RCWPMUXCR0 */
+};
+
+static struct pinmux_cfg ls1012a_pinmux_cfg = {
+ .endian = BIG_ENDIAN,
+ .pmuxcr_offset = 0x430,
+ .pmuxcr_set_bit = 0x10,
+};
+
+static struct pinmux_cfg ls1043a_pinmux_cfg = {
+ .endian = BIG_ENDIAN,
+ .pmuxcr_offset = 0x40C,
+ .pmuxcr_set_bit = 0x10,
+};
+
+static struct pinmux_cfg ls1046a_pinmux_cfg = {
+ .endian = BIG_ENDIAN,
+ .pmuxcr_offset = 0x40C,
+ .pmuxcr_set_bit = 0x80000000,
+};
+
+static const struct of_device_id pinmux_of_match[] = {
+ { .compatible = "fsl,ls1012a-vf610-i2c", .data = &ls1012a_pinmux_cfg},
+ { .compatible = "fsl,ls1043a-vf610-i2c", .data = &ls1043a_pinmux_cfg},
+ { .compatible = "fsl,ls1046a-vf610-i2c", .data = &ls1046a_pinmux_cfg},
+ {},
+};
+MODULE_DEVICE_TABLE(of, pinmux_of_match);
+
+/* The SCFG, Supplemental Configuration Unit, provides SoC specific
+ * configuration and status registers for the device. There is a
+ * SDHC IO VSEL control register on SCFG for some platforms. It's
+ * used to support SDHC IO voltage switching.
+ */
+static const struct of_device_id scfg_device_ids[] = {
+ { .compatible = "fsl,ls1012a-scfg", },
+ { .compatible = "fsl,ls1043a-scfg", },
+ { .compatible = "fsl,ls1046a-scfg", },
+ {}
+};
/*
* sorted list of clock divider, register value pairs
* taken from table 26-5, p.26-9, Freescale i.MX
@@ -210,6 +263,12 @@ struct imx_i2c_struct {
struct pinctrl_state *pinctrl_pins_gpio;
struct imx_i2c_dma *dma;
+ int layerscape_bus_recover;
+ int gpio;
+ int need_set_pmuxcr;
+ int pmuxcr_set;
+ int pmuxcr_endian;
+ void __iomem *pmuxcr_addr;
};
static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
@@ -281,8 +340,8 @@ static inline unsigned char imx_i2c_read
}
/* Functions for DMA support */
-static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
- dma_addr_t phy_addr)
+static int i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
+ dma_addr_t phy_addr)
{
struct imx_i2c_dma *dma;
struct dma_slave_config dma_sconfig;
@@ -291,11 +350,13 @@ static void i2c_imx_dma_request(struct i
dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
if (!dma)
- return;
+ return -ENOMEM;
- dma->chan_tx = dma_request_slave_channel(dev, "tx");
- if (!dma->chan_tx) {
- dev_dbg(dev, "can't request DMA tx channel\n");
+ dma->chan_tx = dma_request_chan(dev, "tx");
+ if (IS_ERR(dma->chan_tx)) {
+ ret = PTR_ERR(dma->chan_tx);
+ if (ret != -ENODEV && ret != -EPROBE_DEFER)
+ dev_err(dev, "can't request DMA tx channel (%d)\n", ret);
goto fail_al;
}
@@ -306,13 +367,15 @@ static void i2c_imx_dma_request(struct i
dma_sconfig.direction = DMA_MEM_TO_DEV;
ret = dmaengine_slave_config(dma->chan_tx, &dma_sconfig);
if (ret < 0) {
- dev_dbg(dev, "can't configure tx channel\n");
+ dev_err(dev, "can't configure tx channel (%d)\n", ret);
goto fail_tx;
}
- dma->chan_rx = dma_request_slave_channel(dev, "rx");
- if (!dma->chan_rx) {
- dev_dbg(dev, "can't request DMA rx channel\n");
+ dma->chan_rx = dma_request_chan(dev, "rx");
+ if (IS_ERR(dma->chan_rx)) {
+ ret = PTR_ERR(dma->chan_rx);
+ if (ret != -ENODEV && ret != -EPROBE_DEFER)
+ dev_err(dev, "can't request DMA rx channel (%d)\n", ret);
goto fail_tx;
}
@@ -323,7 +386,7 @@ static void i2c_imx_dma_request(struct i
dma_sconfig.direction = DMA_DEV_TO_MEM;
ret = dmaengine_slave_config(dma->chan_rx, &dma_sconfig);
if (ret < 0) {
- dev_dbg(dev, "can't configure rx channel\n");
+ dev_err(dev, "can't configure rx channel (%d)\n", ret);
goto fail_rx;
}
@@ -332,7 +395,7 @@ static void i2c_imx_dma_request(struct i
dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
- return;
+ return 0;
fail_rx:
dma_release_channel(dma->chan_rx);
@@ -340,7 +403,8 @@ fail_tx:
dma_release_channel(dma->chan_tx);
fail_al:
devm_kfree(dev, dma);
- dev_info(dev, "can't use DMA, using PIO instead.\n");
+ /* return successfully if there is no dma support */
+ return ret == -ENODEV ? 0 : ret;
}
static void i2c_imx_dma_callback(void *arg)
@@ -878,6 +942,78 @@ static int i2c_imx_read(struct imx_i2c_s
return 0;
}
+/*
+ * Based on the I2C specification, if the data line (SDA) is
+ * stuck low, the master should send nine * clock pulses.
+ * The I2C slave device that held the bus low should release it
+ * sometime within * those nine clocks. Due to this erratum,
+ * the I2C controller cannot generate nine clock pulses.
+ */
+static int i2c_imx_recovery_for_layerscape(struct imx_i2c_struct *i2c_imx)
+{
+ u32 pmuxcr = 0;
+ int ret;
+ unsigned int i, temp;
+
+ /* configure IICx_SCL/GPIO pin as a GPIO */
+ if (i2c_imx->need_set_pmuxcr == 1) {
+ pmuxcr = ioread32be(i2c_imx->pmuxcr_addr);
+ if (i2c_imx->pmuxcr_endian == BIG_ENDIAN)
+ iowrite32be(i2c_imx->pmuxcr_set|pmuxcr,
+ i2c_imx->pmuxcr_addr);
+ else
+ iowrite32(i2c_imx->pmuxcr_set|pmuxcr,
+ i2c_imx->pmuxcr_addr);
+ }
+
+ ret = gpio_request(i2c_imx->gpio, i2c_imx->adapter.name);
+ if (ret) {
+ dev_err(&i2c_imx->adapter.dev,
+ "can't get gpio: %d\n", ret);
+ return ret;
+ }
+
+ /* Configure GPIO pin as an output and open drain. */
+ gpio_direction_output(i2c_imx->gpio, 1);
+ udelay(10);
+
+ /* Write data to generate 9 pulses */
+ for (i = 0; i < 9; i++) {
+ gpio_set_value(i2c_imx->gpio, 1);
+ udelay(10);
+ gpio_set_value(i2c_imx->gpio, 0);
+ udelay(10);
+ }
+ /* ensure that the last level sent is always high */
+ gpio_set_value(i2c_imx->gpio, 1);
+
+ /*
+ * Set I2Cx_IBCR = 0h00 to generate a STOP and then
+ * set I2Cx_IBCR = 0h80 to reset
+ */
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
+ temp &= ~(I2CR_MSTA | I2CR_MTX);
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
+
+ /* Restore the saved value of the register SCFG_RCWPMUXCR0 */
+ if (i2c_imx->need_set_pmuxcr == 1) {
+ if (i2c_imx->pmuxcr_endian == BIG_ENDIAN)
+ iowrite32be(pmuxcr, i2c_imx->pmuxcr_addr);
+ else
+ iowrite32(pmuxcr, i2c_imx->pmuxcr_addr);
+ }
+ /*
+ * Set I2C_IBSR[IBAL] to clear the IBAL bit if-
+ * I2C_IBSR[IBAL] = 1
+ */
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
+ if (temp & I2SR_IAL) {
+ temp &= ~I2SR_IAL;
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
+ }
+ return 0;
+}
+
static int i2c_imx_xfer(struct i2c_adapter *adapter,
struct i2c_msg *msgs, int num)
{
@@ -888,6 +1024,19 @@ static int i2c_imx_xfer(struct i2c_adapt
dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__);
+ /*
+ * workround for ERR010027: ensure that the I2C BUS is idle
+ * before switching to master mode and attempting a Start cycle
+ */
+ result = i2c_imx_bus_busy(i2c_imx, 0);
+ if (result) {
+ /* timeout */
+ if ((result == -ETIMEDOUT) && (i2c_imx->layerscape_bus_recover == 1))
+ i2c_imx_recovery_for_layerscape(i2c_imx);
+ else
+ goto out;
+ }
+
result = pm_runtime_get_sync(i2c_imx->adapter.dev.parent);
if (result < 0)
goto out;
@@ -1030,6 +1179,50 @@ static int i2c_imx_init_recovery_info(st
return 0;
}
+/*
+ * switch SCL and SDA to their GPIO function and do some bitbanging
+ * for bus recovery.
+ * There are platforms such as Layerscape that don't support pinctrl, so add
+ * workaround for layerscape, it has no effect for other platforms.
+ */
+static int i2c_imx_init_recovery_for_layerscape(
+ struct imx_i2c_struct *i2c_imx,
+ struct platform_device *pdev)
+{
+ const struct of_device_id *of_id;
+ struct device_node *np = pdev->dev.of_node;
+ struct pinmux_cfg *pinmux_cfg;
+ struct device_node *scfg_node;
+ void __iomem *scfg_base = NULL;
+
+ i2c_imx->gpio = of_get_named_gpio(np, "fsl-scl-gpio", 0);
+ if (!gpio_is_valid(i2c_imx->gpio)) {
+ dev_info(&pdev->dev, "fsl-scl-gpio not found\n");
+ return 0;
+ }
+ pinmux_cfg = devm_kzalloc(&pdev->dev, sizeof(*pinmux_cfg), GFP_KERNEL);
+ if (!pinmux_cfg)
+ return -ENOMEM;
+
+ i2c_imx->need_set_pmuxcr = 0;
+ of_id = of_match_node(pinmux_of_match, np);
+ if (of_id) {
+ pinmux_cfg = (struct pinmux_cfg *)of_id->data;
+ i2c_imx->pmuxcr_endian = pinmux_cfg->endian;
+ i2c_imx->pmuxcr_set = pinmux_cfg->pmuxcr_set_bit;
+ scfg_node = of_find_matching_node(NULL, scfg_device_ids);
+ if (scfg_node) {
+ scfg_base = of_iomap(scfg_node, 0);
+ if (scfg_base) {
+ i2c_imx->pmuxcr_addr = scfg_base + pinmux_cfg->pmuxcr_offset;
+ i2c_imx->need_set_pmuxcr = 1;
+ }
+ }
+ }
+ i2c_imx->layerscape_bus_recover = 1;
+ return 0;
+}
+
static u32 i2c_imx_func(struct i2c_adapter *adapter)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL
@@ -1085,6 +1278,11 @@ static int i2c_imx_probe(struct platform
i2c_imx->adapter.dev.of_node = pdev->dev.of_node;
i2c_imx->base = base;
+ /* Init optional bus recovery for layerscape */
+ ret = i2c_imx_init_recovery_for_layerscape(i2c_imx, pdev);
+ if (ret)
+ return ret;
+
/* Get I2C clock */
i2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(i2c_imx->clk)) {
@@ -1104,7 +1302,8 @@ static int i2c_imx_probe(struct platform
pdev->name, i2c_imx);
if (ret) {
dev_err(&pdev->dev, "can't claim irq %d\n", irq);
- goto clk_disable;
+ clk_disable_unprepare(i2c_imx->clk);
+ return ret;
}
/* Init queue */
@@ -1151,25 +1350,31 @@ static int i2c_imx_probe(struct platform
pm_runtime_mark_last_busy(&pdev->dev);
pm_runtime_put_autosuspend(&pdev->dev);
+ /* Init DMA config if supported */
+ ret = i2c_imx_dma_request(i2c_imx, phy_addr);
+ if (ret) {
+ if (ret != -EPROBE_DEFER)
+ dev_info(&pdev->dev, "can't use DMA, using PIO instead.\n");
+ else
+ goto del_adapter;
+ }
+
dev_dbg(&i2c_imx->adapter.dev, "claimed irq %d\n", irq);
dev_dbg(&i2c_imx->adapter.dev, "device resources: %pR\n", res);
dev_dbg(&i2c_imx->adapter.dev, "adapter name: \"%s\"\n",
i2c_imx->adapter.name);
- dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
-
- /* Init DMA config if supported */
- i2c_imx_dma_request(i2c_imx, phy_addr);
+ dev_info(&i2c_imx->adapter.dev, "IMX I2C adapter registered\n");
return 0; /* Return OK */
+del_adapter:
+ i2c_del_adapter(&i2c_imx->adapter);
rpm_disable:
pm_runtime_put_noidle(&pdev->dev);
pm_runtime_disable(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
pm_runtime_dont_use_autosuspend(&pdev->dev);
-clk_disable:
- clk_disable_unprepare(i2c_imx->clk);
return ret;
}
--- a/drivers/i2c/muxes/i2c-mux-pca954x.c
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -85,6 +85,7 @@ struct pca954x {
struct irq_domain *irq;
unsigned int irq_mask;
raw_spinlock_t lock;
+ u8 disable_mux; /* do not disable mux if val not 0 */
};
/* Provide specs for the PCA954x types we know about */
@@ -221,6 +222,13 @@ static int pca954x_deselect_mux(struct i
if (!(data->deselect & (1 << chan)))
return 0;
+#ifdef CONFIG_ARCH_LAYERSCAPE
+ if (data->disable_mux != 0)
+ data->last_chan = data->chip->nchans;
+ else
+ data->last_chan = 0;
+ return pca954x_reg_write(muxc->parent, client, data->disable_mux);
+#endif
/* Deselect active channel */
data->last_chan = 0;
return pca954x_reg_write(muxc->parent, client, data->last_chan);
@@ -361,6 +369,28 @@ static int pca954x_probe(struct i2c_clie
return -ENOMEM;
data = i2c_mux_priv(muxc);
+#ifdef CONFIG_ARCH_LAYERSCAPE
+ /* The point here is that you must not disable a mux if there
+ * are no pullups on the input or you mess up the I2C. This
+ * needs to be put into the DTS really as the kernel cannot
+ * know this otherwise.
+ */
+ match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
+ if (match)
+ data->chip = of_device_get_match_data(&client->dev);
+ else
+ data->chip = &chips[id->driver_data];
+
+ data->disable_mux = of_node &&
+ of_property_read_bool(of_node, "i2c-mux-never-disable") &&
+ data->chip->muxtype == pca954x_ismux ?
+ data->chip->enable : 0;
+ /* force the first selection */
+ if (data->disable_mux != 0)
+ data->last_chan = data->chip->nchans;
+ else
+ data->last_chan = 0;
+#endif
i2c_set_clientdata(client, muxc);
data->client = client;
@@ -373,18 +403,23 @@ static int pca954x_probe(struct i2c_clie
* that the mux is in fact present. This also
* initializes the mux to disconnected state.
*/
+#ifdef CONFIG_ARCH_LAYERSCAPE
+ if (i2c_smbus_write_byte(client, data->disable_mux) < 0) {
+#else
if (i2c_smbus_write_byte(client, 0) < 0) {
+#endif
dev_warn(&client->dev, "probe failed\n");
return -ENODEV;
}
+#ifndef CONFIG_ARCH_LAYERSCAPE
match = of_match_device(of_match_ptr(pca954x_of_match), &client->dev);
if (match)
data->chip = of_device_get_match_data(&client->dev);
else
data->chip = &chips[id->driver_data];
-
data->last_chan = 0; /* force the first selection */
+#endif
idle_disconnect_dt = of_node &&
of_property_read_bool(of_node, "i2c-mux-idle-disconnect");
@@ -454,6 +489,13 @@ static int pca954x_resume(struct device
struct i2c_mux_core *muxc = i2c_get_clientdata(client);
struct pca954x *data = i2c_mux_priv(muxc);
+#ifdef CONFIG_ARCH_LAYERSCAPE
+ if (data->disable_mux != 0)
+ data->last_chan = data->chip->nchans;
+ else
+ data->last_chan = 0;
+ return i2c_smbus_write_byte(client, data->disable_mux);
+#endif
data->last_chan = 0;
return i2c_smbus_write_byte(client, 0);
}
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