From: Guenter Roeck <gro...@juniper.net>
Introduce Juniper's PTX PMB CPLD I2C multiplexer driver.
Signed-off-by: Debjit Ghosh <dgh...@juniper.net>
Signed-off-by: Georgi Vlaev <gvl...@juniper.net>
Signed-off-by: Guenter Roeck <gro...@juniper.net>
Signed-off-by: JawaharBalaji Thirumalaisamy <jawah...@juniper.net>
Signed-off-by: Rajat Jain <rajatj...@juniper.net>
[Ported from Juniper kernel]
Signed-off-by: Pantelis Antoniou <pantelis.anton...@konsulko.com>
---
drivers/i2c/muxes/Kconfig | 11 ++
drivers/i2c/muxes/Makefile | 1 +
drivers/i2c/muxes/i2c-mux-ptxpmb.c | 299 +++++++++++++++++++++++++++++++++++++
3 files changed, 311 insertions(+)
create mode 100644 drivers/i2c/muxes/i2c-mux-ptxpmb.c
diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
index e280c8e..f45a9cb 100644
--- a/drivers/i2c/muxes/Kconfig
+++ b/drivers/i2c/muxes/Kconfig
@@ -61,6 +61,17 @@ config I2C_MUX_PINCTRL
This driver can also be built as a module. If so, the module will be
called pinctrl-i2cmux.
+config I2C_MUX_PTXPMB
+ tristate "Juniper PTX PMB CPLD I2C multiplexer"
+ depends on MFD_JUNIPER_CPLD
+ default y if MFD_JUNIPER_CPLD
+ help
+ Select this to enable the Juniper PTX PMB CPLD I2C multiplexer driver
+ on the relevant Juniper platforms.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mux-ptxpmb-cpld.
+
config I2C_MUX_REG
tristate "Register-based I2C multiplexer"
help
diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile
index 7c267c2..78d8cba 100644
--- a/drivers/i2c/muxes/Makefile
+++ b/drivers/i2c/muxes/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_I2C_MUX_GPIO) += i2c-mux-gpio.o
obj-$(CONFIG_I2C_MUX_PCA9541) += i2c-mux-pca9541.o
obj-$(CONFIG_I2C_MUX_PCA954x) += i2c-mux-pca954x.o
obj-$(CONFIG_I2C_MUX_PINCTRL) += i2c-mux-pinctrl.o
+obj-$(CONFIG_I2C_MUX_PTXPMB) += i2c-mux-ptxpmb.o
obj-$(CONFIG_I2C_MUX_REG) += i2c-mux-reg.o
ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG
diff --git a/drivers/i2c/muxes/i2c-mux-ptxpmb.c
b/drivers/i2c/muxes/i2c-mux-ptxpmb.c
new file mode 100644
index 0000000..e8c7aee
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-ptxpmb.c
@@ -0,0 +1,299 @@
+/*
+ * PTX PMB CPLD I2C multiplexer
+ *
+ * Copyright (c) 2012, Juniper Networks. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/mfd/ptxpmb_cpld.h>
+#include <linux/io.h>
+#include <linux/of_device.h>
+
+struct i2c_mux_ptxpmb {
+ struct device *dev;
+ struct ptxpmb_mux_data *pdata;
+ struct pmb_boot_cpld __iomem *cpld;
+ struct i2c_adapter *parent;
+ int bus_count;
+ struct i2c_mux_core *muxc;
+};
+
+static const struct of_device_id i2c_mux_ptxpmb_of_match[] = {
+ { .compatible = "jnx,i2c-mux-ptxpmb-cpld",
+ .data = (void *)CPLD_TYPE_PTXPMB },
+ { .compatible = "jnx,i2c-mux-ngpmb-bcpld",
+ .data = (void *)CPLD_TYPE_NGPMB },
+ { },
+};
+MODULE_DEVICE_TABLE(of, i2c_mux_ptxpmb_of_match);
+
+#define I2C_GRP_FORCE_EN 0x80
+
+static int i2c_mux_ptxpmb_select(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct i2c_mux_ptxpmb *mux = i2c_mux_priv(muxc);
+ struct ptxpmb_mux_data *pdata = mux->pdata;
+ u8 group, enable, val;
+
+ switch (pdata->cpld_type) {
+ case CPLD_TYPE_PTXPMB:
+ group = chan % pdata->num_channels;
+ enable = 1 << (chan / pdata->num_channels);
+ /*
+ * Writing into the enable register does not have an effect on
+ * FPC with P2020. It is necessary for FPC with P5020/P5040.
+ * The uKernel for SPMB uses undocumented CPLD registers to set
+ * group enable values (i2c_group_sel_force and
+ * i2c_group_en_force at offset 0x33 and 0x34). Bit 7 in
+ * i2c_group_sel_force must be set for this to work.
+ * i2c_group_en_force is active-low. This applies to SPMB with
+ * P2020; behavior with P5020/P5040 is unknown at this time.
+ */
+ if (pdata->use_force) {
+ iowrite8(group | I2C_GRP_FORCE_EN,
+ &mux->cpld->i2c_group_sel_force);
+ iowrite8(~enable, &mux->cpld->i2c_group_en_force);
+ } else {
+ iowrite8(group, &mux->cpld->i2c_group_sel);
+ ioread8(&mux->cpld->i2c_group_sel);
+ iowrite8(enable, &mux->cpld->i2c_group_en);
+ ioread8(&mux->cpld->i2c_group_en);
+ }
+ break;
+ case CPLD_TYPE_NGPMB:
+ val = ioread8(&mux->cpld->gpio_2);
+ val &= ~NGPMB_I2C_GRP_SEL_MASK;
+ val |= (chan << NGPMB_I2C_GRP_SEL_LSB) & NGPMB_I2C_GRP_SEL_MASK;
+ iowrite8(val, &mux->cpld->gpio_2);
+ break;
+ }
+ udelay(50);
+
+ return 0;
+}
+
+static int i2c_mux_ptxpmb_deselect(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct i2c_mux_ptxpmb *mux = i2c_mux_priv(muxc);
+ u8 val;
+
+ switch (mux->pdata->cpld_type) {
+ case CPLD_TYPE_PTXPMB:
+ /*
+ * Restore defaults. Note that setting i2c_group_en does not
+ * have an effect on FPC with P2020, but is necessary for FPC
+ * with P5020/P5040.
+ */
+ if (mux->pdata->use_force) {
+ iowrite8(0 | I2C_GRP_FORCE_EN,
+ &mux->cpld->i2c_group_sel_force);
+ iowrite8(0xff, &mux->cpld->i2c_group_en_force);
+ } else {
+ iowrite8(0, &mux->cpld->i2c_group_sel);
+ ioread8(&mux->cpld->i2c_group_sel);
+ iowrite8(0, &mux->cpld->i2c_group_en);
+ ioread8(&mux->cpld->i2c_group_en);
+ }
+ break;
+ case CPLD_TYPE_NGPMB:
+ /* Use the (unconnected) channel 3 to deselct */
+ val = ioread8(&mux->cpld->gpio_2);
+ val &= ~NGPMB_I2C_GRP_SEL_MASK;
+ val |= (3 << NGPMB_I2C_GRP_SEL_LSB) & NGPMB_I2C_GRP_SEL_MASK;
+ iowrite8(val, &mux->cpld->gpio_2);
+ break;
+ }
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static int i2c_mux_ptxpmb_parse_dt(struct i2c_mux_ptxpmb *mux,
+ struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ int ret;
+ struct device_node *adapter_np;
+ struct i2c_adapter *adapter;
+ const struct of_device_id *match;
+
+ if (!np)
+ return 0;
+
+ mux->pdata = devm_kzalloc(dev, sizeof(*mux->pdata), GFP_KERNEL);
+ if (!mux->pdata)
+ return -ENOMEM;
+
+ match = of_match_device(i2c_mux_ptxpmb_of_match, dev);
+ if (match)
+ mux->pdata->cpld_type = (int)(unsigned long)match->data;
+
+ ret = of_property_read_u32(np, "num-enable", &mux->pdata->num_enable);
+ if (ret) {
+ dev_err(dev, "num-enable missing\n");
+ return -ENODEV;
+ }
+
+ ret = of_property_read_u32(np, "num-channels",
+ &mux->pdata->num_channels);
+ if (ret)
+ mux->pdata->num_channels = 8;
+
+ ret = of_property_read_u32(np, "base-bus-num",
+ &mux->pdata->base_bus_num);
+ if (ret)
+ mux->pdata->base_bus_num = 0;
+
+ if (of_find_property(np, "use-force", NULL))
+ mux->pdata->use_force = true;
+
+ adapter_np = of_parse_phandle(np, "i2c-parent", 0);
+ if (!adapter_np) {
+ dev_err(dev, "Cannot parse i2c-parent\n");
+ return -ENODEV;
+ }
+ adapter = of_find_i2c_adapter_by_node(adapter_np);
+ if (!adapter) {
+ dev_err(dev, "Cannot find parent bus\n");
+ return -ENODEV;
+ }
+ mux->pdata->parent_bus_num = i2c_adapter_id(adapter);
+ put_device(&adapter->dev);
+
+ return 0;
+}
+#else
+static inline int i2c_mux_ptxpmb_parse_dt(struct i2c_mux_ptxpmb *mux,
+ struct device *dev)
+{
+ return 0;
+}
+#endif
+
+static int i2c_mux_ptxpmb_probe(struct platform_device *pdev)
+{
+ struct i2c_mux_ptxpmb *mux;
+ struct i2c_mux_core *muxc;
+ int i, ret;
+ struct resource *res;
+ struct device *dev = &pdev->dev;
+
+ mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, mux);
+
+ mux->dev = dev;
+
+ mux->pdata = dev->platform_data;
+ if (!mux->pdata) {
+ ret = i2c_mux_ptxpmb_parse_dt(mux, dev);
+ if (ret < 0)
+ return ret;
+ }
+ if (!mux->pdata) {
+ dev_err(dev, "No platform / devicetree data\n");
+ return -ENODEV;
+ }
+
+ if (mux->pdata->num_enable <= 0 || mux->pdata->num_enable > 8 ||
+ mux->pdata->num_channels <= 0 || mux->pdata->num_channels > 8) {
+ dev_err(dev, "Invalid platform data\n");
+ return -EINVAL;
+ }
+
+ mux->bus_count = mux->pdata->num_enable * mux->pdata->num_channels;
+
+ mux->parent = i2c_get_adapter(mux->pdata->parent_bus_num);
+ if (!mux->parent) {
+ dev_err(dev, "Parent adapter (%d) not found\n",
+ mux->pdata->parent_bus_num);
+ return -ENODEV;
+ }
+
+ muxc = i2c_mux_alloc(mux->parent, dev, mux->bus_count, 0, 0,
+ i2c_mux_ptxpmb_select, i2c_mux_ptxpmb_deselect);
+ if (!muxc) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ muxc->priv = mux;
+ mux->muxc = muxc;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(dev, "No memory resource\n");
+ ret = -ENODEV;
+ goto err;
+ }
+
+ mux->cpld = devm_ioremap_nocache(dev, res->start, resource_size(res));
+ if (!mux->cpld) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ for (i = 0; i < mux->bus_count; i++) {
+ u32 bus = mux->pdata->base_bus_num ?
+ mux->pdata->base_bus_num + i : 0;
+
+ ret = i2c_mux_add_adapter(muxc, bus, i, 0);
+ if (ret) {
+ dev_err(dev, "Failed to add adapter %d\n", i);
+ goto err_del_adapter;
+ }
+ }
+
+ return 0;
+
+err_del_adapter:
+ i2c_mux_del_adapters(mux->muxc);
+err:
+ i2c_put_adapter(mux->parent);
+ return ret;
+}
+
+static int i2c_mux_ptxpmb_remove(struct platform_device *pdev)
+{
+ struct i2c_mux_ptxpmb *mux = platform_get_drvdata(pdev);
+
+ i2c_mux_del_adapters(mux->muxc);
+ i2c_put_adapter(mux->parent);
+
+ return 0;
+}
+
+static struct platform_driver i2c_mux_ptxpmb_driver = {
+ .driver = {
+ .name = "i2c-mux-ptxpmb-cpld",
+ .owner = THIS_MODULE,
+ .of_match_table = i2c_mux_ptxpmb_of_match,
+ },
+ .probe = i2c_mux_ptxpmb_probe,
+ .remove = i2c_mux_ptxpmb_remove,
+};
+
+module_platform_driver(i2c_mux_ptxpmb_driver);
+
+MODULE_DESCRIPTION("ptxpmb CPLD I2C multiplexer driver");
+MODULE_AUTHOR("Guenter Roeck <gro...@juniper.net>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:i2c-mux-ptxpmb-cpld");
--
1.9.1
