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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /drivers/i2c/busses/i2c-powermac.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/i2c/busses/i2c-powermac.c')
-rw-r--r-- | drivers/i2c/busses/i2c-powermac.c | 456 |
1 files changed, 456 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-powermac.c b/drivers/i2c/busses/i2c-powermac.c new file mode 100644 index 000000000..3e38e1149 --- /dev/null +++ b/drivers/i2c/busses/i2c-powermac.c @@ -0,0 +1,456 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + i2c Support for Apple SMU Controller + + Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp. + <benh@kernel.crashing.org> + + +*/ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/i2c.h> +#include <linux/device.h> +#include <linux/platform_device.h> +#include <linux/of_irq.h> +#include <asm/prom.h> +#include <asm/pmac_low_i2c.h> + +MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); +MODULE_DESCRIPTION("I2C driver for Apple PowerMac"); +MODULE_LICENSE("GPL"); + +/* + * SMBUS-type transfer entrypoint + */ +static s32 i2c_powermac_smbus_xfer( struct i2c_adapter* adap, + u16 addr, + unsigned short flags, + char read_write, + u8 command, + int size, + union i2c_smbus_data* data) +{ + struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); + int rc = 0; + int read = (read_write == I2C_SMBUS_READ); + int addrdir = (addr << 1) | read; + int mode, subsize, len; + u32 subaddr; + u8 *buf; + u8 local[2]; + + if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) { + mode = pmac_i2c_mode_std; + subsize = 0; + subaddr = 0; + } else { + mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub; + subsize = 1; + subaddr = command; + } + + switch (size) { + case I2C_SMBUS_QUICK: + buf = NULL; + len = 0; + break; + case I2C_SMBUS_BYTE: + case I2C_SMBUS_BYTE_DATA: + buf = &data->byte; + len = 1; + break; + case I2C_SMBUS_WORD_DATA: + if (!read) { + local[0] = data->word & 0xff; + local[1] = (data->word >> 8) & 0xff; + } + buf = local; + len = 2; + break; + + /* Note that these are broken vs. the expected smbus API where + * on reads, the length is actually returned from the function, + * but I think the current API makes no sense and I don't want + * any driver that I haven't verified for correctness to go + * anywhere near a pmac i2c bus anyway ... + * + * I'm also not completely sure what kind of phases to do between + * the actual command and the data (what I am _supposed_ to do that + * is). For now, I assume writes are a single stream and reads have + * a repeat start/addr phase (but not stop in between) + */ + case I2C_SMBUS_BLOCK_DATA: + buf = data->block; + len = data->block[0] + 1; + break; + case I2C_SMBUS_I2C_BLOCK_DATA: + buf = &data->block[1]; + len = data->block[0]; + break; + + default: + return -EINVAL; + } + + rc = pmac_i2c_open(bus, 0); + if (rc) { + dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc); + return rc; + } + + rc = pmac_i2c_setmode(bus, mode); + if (rc) { + dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n", + mode, rc); + goto bail; + } + + rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len); + if (rc) { + if (rc == -ENXIO) + dev_dbg(&adap->dev, + "I2C transfer at 0x%02x failed, size %d, " + "err %d\n", addrdir >> 1, size, rc); + else + dev_err(&adap->dev, + "I2C transfer at 0x%02x failed, size %d, " + "err %d\n", addrdir >> 1, size, rc); + goto bail; + } + + if (size == I2C_SMBUS_WORD_DATA && read) { + data->word = ((u16)local[1]) << 8; + data->word |= local[0]; + } + + bail: + pmac_i2c_close(bus); + return rc; +} + +/* + * Generic i2c master transfer entrypoint. This driver only support single + * messages (for "lame i2c" transfers). Anything else should use the smbus + * entry point + */ +static int i2c_powermac_master_xfer( struct i2c_adapter *adap, + struct i2c_msg *msgs, + int num) +{ + struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); + int rc = 0; + int addrdir; + + if (msgs->flags & I2C_M_TEN) + return -EINVAL; + addrdir = i2c_8bit_addr_from_msg(msgs); + + rc = pmac_i2c_open(bus, 0); + if (rc) { + dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc); + return rc; + } + rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); + if (rc) { + dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n", + pmac_i2c_mode_std, rc); + goto bail; + } + rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len); + if (rc < 0) { + if (rc == -ENXIO) + dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n", + addrdir & 1 ? "read from" : "write to", + addrdir >> 1, rc); + else + dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n", + addrdir & 1 ? "read from" : "write to", + addrdir >> 1, rc); + } + bail: + pmac_i2c_close(bus); + return rc < 0 ? rc : 1; +} + +static u32 i2c_powermac_func(struct i2c_adapter * adapter) +{ + return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | + I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | + I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C; +} + +/* For now, we only handle smbus */ +static const struct i2c_algorithm i2c_powermac_algorithm = { + .smbus_xfer = i2c_powermac_smbus_xfer, + .master_xfer = i2c_powermac_master_xfer, + .functionality = i2c_powermac_func, +}; + +static const struct i2c_adapter_quirks i2c_powermac_quirks = { + .max_num_msgs = 1, +}; + +static int i2c_powermac_remove(struct platform_device *dev) +{ + struct i2c_adapter *adapter = platform_get_drvdata(dev); + + i2c_del_adapter(adapter); + memset(adapter, 0, sizeof(*adapter)); + + return 0; +} + +static u32 i2c_powermac_get_addr(struct i2c_adapter *adap, + struct pmac_i2c_bus *bus, + struct device_node *node) +{ + u32 prop; + int ret; + + /* First check for valid "reg" */ + ret = of_property_read_u32(node, "reg", &prop); + if (ret == 0) + return (prop & 0xff) >> 1; + + /* Then check old-style "i2c-address" */ + ret = of_property_read_u32(node, "i2c-address", &prop); + if (ret == 0) + return (prop & 0xff) >> 1; + + /* Now handle some devices with missing "reg" properties */ + if (of_node_name_eq(node, "cereal")) + return 0x60; + else if (of_node_name_eq(node, "deq")) + return 0x34; + + dev_warn(&adap->dev, "No i2c address for %pOF\n", node); + + return 0xffffffff; +} + +static void i2c_powermac_create_one(struct i2c_adapter *adap, + const char *type, + u32 addr) +{ + struct i2c_board_info info = {}; + struct i2c_client *newdev; + + strncpy(info.type, type, sizeof(info.type)); + info.addr = addr; + newdev = i2c_new_client_device(adap, &info); + if (IS_ERR(newdev)) + dev_err(&adap->dev, + "i2c-powermac: Failure to register missing %s\n", + type); +} + +static void i2c_powermac_add_missing(struct i2c_adapter *adap, + struct pmac_i2c_bus *bus, + bool found_onyx) +{ + struct device_node *busnode = pmac_i2c_get_bus_node(bus); + int rc; + + /* Check for the onyx audio codec */ +#define ONYX_REG_CONTROL 67 + if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) { + union i2c_smbus_data data; + + rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ, + ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA, + &data); + if (rc >= 0) + i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46); + + rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ, + ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA, + &data); + if (rc >= 0) + i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47); + } +} + +static bool i2c_powermac_get_type(struct i2c_adapter *adap, + struct device_node *node, + u32 addr, char *type, int type_size) +{ + char tmp[16]; + + /* + * Note: we do _NOT_ want the standard i2c drivers to match with any of + * our powermac stuff unless they have been specifically modified to + * handle it on a case by case basis. For example, for thermal control, + * things like lm75 etc... shall match with their corresponding + * windfarm drivers, _NOT_ the generic ones, so we force a prefix of + * 'MAC', onto the modalias to make that happen + */ + + /* First try proper modalias */ + if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) { + snprintf(type, type_size, "MAC,%s", tmp); + return true; + } + + /* Now look for known workarounds */ + if (of_node_name_eq(node, "deq")) { + /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */ + if (addr == 0x34) { + snprintf(type, type_size, "MAC,tas3001"); + return true; + } else if (addr == 0x35) { + snprintf(type, type_size, "MAC,tas3004"); + return true; + } + } + + dev_err(&adap->dev, "i2c-powermac: modalias failure on %pOF\n", node); + return false; +} + +static void i2c_powermac_register_devices(struct i2c_adapter *adap, + struct pmac_i2c_bus *bus) +{ + struct i2c_client *newdev; + struct device_node *node; + bool found_onyx = false; + + /* + * In some cases we end up with the via-pmu node itself, in this + * case we skip this function completely as the device-tree will + * not contain anything useful. + */ + if (of_node_name_eq(adap->dev.of_node, "via-pmu")) + return; + + for_each_child_of_node(adap->dev.of_node, node) { + struct i2c_board_info info = {}; + u32 addr; + + /* Get address & channel */ + addr = i2c_powermac_get_addr(adap, bus, node); + if (addr == 0xffffffff) + continue; + + /* Multibus setup, check channel */ + if (!pmac_i2c_match_adapter(node, adap)) + continue; + + dev_dbg(&adap->dev, "i2c-powermac: register %pOF\n", node); + + /* + * Keep track of some device existence to handle + * workarounds later. + */ + if (of_device_is_compatible(node, "pcm3052")) + found_onyx = true; + + /* Make up a modalias */ + if (!i2c_powermac_get_type(adap, node, addr, + info.type, sizeof(info.type))) { + continue; + } + + /* Fill out the rest of the info structure */ + info.addr = addr; + info.irq = irq_of_parse_and_map(node, 0); + info.of_node = of_node_get(node); + + newdev = i2c_new_client_device(adap, &info); + if (IS_ERR(newdev)) { + dev_err(&adap->dev, "i2c-powermac: Failure to register" + " %pOF\n", node); + of_node_put(node); + /* We do not dispose of the interrupt mapping on + * purpose. It's not necessary (interrupt cannot be + * re-used) and somebody else might have grabbed it + * via direct DT lookup so let's not bother + */ + continue; + } + } + + /* Additional workarounds */ + i2c_powermac_add_missing(adap, bus, found_onyx); +} + +static int i2c_powermac_probe(struct platform_device *dev) +{ + struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev); + struct device_node *parent; + struct i2c_adapter *adapter; + int rc; + + if (bus == NULL) + return -EINVAL; + adapter = pmac_i2c_get_adapter(bus); + + /* Ok, now we need to make up a name for the interface that will + * match what we used to do in the past, that is basically the + * controller's parent device node for keywest. PMU didn't have a + * naming convention and SMU has a different one + */ + switch(pmac_i2c_get_type(bus)) { + case pmac_i2c_bus_keywest: + parent = of_get_parent(pmac_i2c_get_controller(bus)); + if (parent == NULL) + return -EINVAL; + snprintf(adapter->name, sizeof(adapter->name), "%pOFn %d", + parent, + pmac_i2c_get_channel(bus)); + of_node_put(parent); + break; + case pmac_i2c_bus_pmu: + snprintf(adapter->name, sizeof(adapter->name), "pmu %d", + pmac_i2c_get_channel(bus)); + break; + case pmac_i2c_bus_smu: + /* This is not what we used to do but I'm fixing drivers at + * the same time as this change + */ + snprintf(adapter->name, sizeof(adapter->name), "smu %d", + pmac_i2c_get_channel(bus)); + break; + default: + return -EINVAL; + } + + platform_set_drvdata(dev, adapter); + adapter->algo = &i2c_powermac_algorithm; + adapter->quirks = &i2c_powermac_quirks; + i2c_set_adapdata(adapter, bus); + adapter->dev.parent = &dev->dev; + + /* Clear of_node to skip automatic registration of i2c child nodes */ + adapter->dev.of_node = NULL; + rc = i2c_add_adapter(adapter); + if (rc) { + printk(KERN_ERR "i2c-powermac: Adapter %s registration " + "failed\n", adapter->name); + memset(adapter, 0, sizeof(*adapter)); + return rc; + } + + printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name); + + /* Use custom child registration due to Apple device-tree funkyness */ + adapter->dev.of_node = dev->dev.of_node; + i2c_powermac_register_devices(adapter, bus); + + return 0; +} + +static struct platform_driver i2c_powermac_driver = { + .probe = i2c_powermac_probe, + .remove = i2c_powermac_remove, + .driver = { + .name = "i2c-powermac", + .bus = &platform_bus_type, + }, +}; + +module_platform_driver(i2c_powermac_driver); + +MODULE_ALIAS("platform:i2c-powermac"); |