mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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misc: add FPC202 dual port controller driver
The TI FPC202 dual port controller serves as a low-speed signal aggregator for common port types such as SFP, QSFP, Mini-SAS HD, and others. It aggregates GPIO and I2C signals across two downstream ports, acting as both a GPIO controller and an I2C address translator for up to two logical devices per port. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> Signed-off-by: Romain Gantois <romain.gantois@bootlin.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Andi Shyti <andi.shyti@kernel.org> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
This commit is contained in:
Romain Gantois
Wolfram Sang
parent
c3f5524188
commit
1e5c9b1efa
@ -24211,6 +24211,7 @@ M: Romain Gantois <romain.gantois@bootlin.com>
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L: linux-kernel@vger.kernel.org
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S: Maintained
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F: Documentation/devicetree/bindings/misc/ti,fpc202.yaml
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F: drivers/misc/ti_fpc202.c
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TI FPD-LINK DRIVERS
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M: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
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@ -114,6 +114,18 @@ config RPMB
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If unsure, select N.
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config TI_FPC202
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tristate "TI FPC202 Dual Port Controller"
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depends on I2C
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select GPIOLIB
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select I2C_ATR
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help
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If you say yes here you get support for the Texas Instruments FPC202
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Dual Port Controller.
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This driver can also be built as a module. If so, the module will be
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called fpc202.
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config TIFM_CORE
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tristate "TI Flash Media interface support"
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depends on PCI
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@ -12,6 +12,7 @@ obj-$(CONFIG_ATMEL_SSC) += atmel-ssc.o
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obj-$(CONFIG_DUMMY_IRQ) += dummy-irq.o
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obj-$(CONFIG_ICS932S401) += ics932s401.o
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obj-$(CONFIG_LKDTM) += lkdtm/
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obj-$(CONFIG_TI_FPC202) += ti_fpc202.o
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obj-$(CONFIG_TIFM_CORE) += tifm_core.o
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obj-$(CONFIG_TIFM_7XX1) += tifm_7xx1.o
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obj-$(CONFIG_PHANTOM) += phantom.o
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438
drivers/misc/ti_fpc202.c
Normal file
438
drivers/misc/ti_fpc202.c
Normal file
@ -0,0 +1,438 @@
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* ti_fpc202.c - FPC202 Dual Port Controller driver
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*
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* Copyright (C) 2024 Bootlin
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*
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*/
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#include <linux/cleanup.h>
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/i2c-atr.h>
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#include <linux/gpio/consumer.h>
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#include <linux/gpio/driver.h>
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#include <linux/module.h>
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#define FPC202_NUM_PORTS 2
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#define FPC202_ALIASES_PER_PORT 2
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/*
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* GPIO: port mapping
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*
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* 0: P0_S0_IN_A
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* 1: P0_S1_IN_A
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* 2: P1_S0_IN_A
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* 3: P1_S1_IN_A
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* 4: P0_S0_IN_B
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* ...
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* 8: P0_S0_IN_C
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* ...
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* 12: P0_S0_OUT_A
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* ...
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* 16: P0_S0_OUT_B
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* ...
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* 19: P1_S1_OUT_B
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*
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*/
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#define FPC202_GPIO_COUNT 20
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#define FPC202_GPIO_P0_S0_IN_B 4
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#define FPC202_GPIO_P0_S0_OUT_A 12
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#define FPC202_REG_IN_A_INT 0x6
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#define FPC202_REG_IN_C_IN_B 0x7
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#define FPC202_REG_OUT_A_OUT_B 0x8
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#define FPC202_REG_OUT_A_OUT_B_VAL 0xa
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#define FPC202_REG_MOD_DEV(port, dev) (0xb4 + ((port) * 4) + (dev))
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#define FPC202_REG_AUX_DEV(port, dev) (0xb6 + ((port) * 4) + (dev))
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/*
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* The FPC202 doesn't support turning off address translation on a single port.
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* So just set an invalid I2C address as the translation target when no client
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* address is attached.
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*/
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#define FPC202_REG_DEV_INVALID 0
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/* Even aliases are assigned to device 0 and odd aliases to device 1 */
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#define fpc202_dev_num_from_alias(alias) ((alias) % 2)
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struct fpc202_priv {
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struct i2c_client *client;
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struct i2c_atr *atr;
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struct gpio_desc *en_gpio;
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struct gpio_chip gpio;
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/* Lock REG_MOD/AUX_DEV and addr_caches during attach/detach */
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struct mutex reg_dev_lock;
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/* Cached device addresses for both ports and their devices */
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u8 addr_caches[2][2];
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/* Keep track of which ports were probed */
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DECLARE_BITMAP(probed_ports, FPC202_NUM_PORTS);
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};
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static void fpc202_fill_alias_table(struct i2c_client *client, u16 *aliases, int port_id)
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{
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u16 first_alias;
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int i;
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/*
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* There is a predefined list of aliases for each FPC202 I2C
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* self-address. This allows daisy-chained FPC202 units to
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* automatically take on different sets of aliases.
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* Each port of an FPC202 unit is assigned two aliases from this list.
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*/
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first_alias = 0x10 + 4 * port_id + 8 * ((u16)client->addr - 2);
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for (i = 0; i < FPC202_ALIASES_PER_PORT; i++)
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aliases[i] = first_alias + i;
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}
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static int fpc202_gpio_get_dir(int offset)
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{
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return offset < FPC202_GPIO_P0_S0_OUT_A ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT;
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}
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static int fpc202_read(struct fpc202_priv *priv, u8 reg)
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{
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int val;
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val = i2c_smbus_read_byte_data(priv->client, reg);
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return val;
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}
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static int fpc202_write(struct fpc202_priv *priv, u8 reg, u8 value)
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{
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return i2c_smbus_write_byte_data(priv->client, reg, value);
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}
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static void fpc202_set_enable(struct fpc202_priv *priv, int enable)
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{
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if (!priv->en_gpio)
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return;
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gpiod_set_value(priv->en_gpio, enable);
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}
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static void fpc202_gpio_set(struct gpio_chip *chip, unsigned int offset,
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int value)
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{
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struct fpc202_priv *priv = gpiochip_get_data(chip);
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int ret;
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u8 val;
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if (fpc202_gpio_get_dir(offset) == GPIO_LINE_DIRECTION_IN)
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return;
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ret = fpc202_read(priv, FPC202_REG_OUT_A_OUT_B_VAL);
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if (ret < 0) {
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dev_err(&priv->client->dev, "Failed to set GPIO %d value! err %d\n", offset, ret);
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return;
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}
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val = (u8)ret;
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if (value)
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val |= BIT(offset - FPC202_GPIO_P0_S0_OUT_A);
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else
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val &= ~BIT(offset - FPC202_GPIO_P0_S0_OUT_A);
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fpc202_write(priv, FPC202_REG_OUT_A_OUT_B_VAL, val);
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}
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static int fpc202_gpio_get(struct gpio_chip *chip, unsigned int offset)
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{
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struct fpc202_priv *priv = gpiochip_get_data(chip);
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u8 reg, bit;
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int ret;
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if (offset < FPC202_GPIO_P0_S0_IN_B) {
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reg = FPC202_REG_IN_A_INT;
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bit = BIT(4 + offset);
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} else if (offset < FPC202_GPIO_P0_S0_OUT_A) {
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reg = FPC202_REG_IN_C_IN_B;
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bit = BIT(offset - FPC202_GPIO_P0_S0_IN_B);
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} else {
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reg = FPC202_REG_OUT_A_OUT_B_VAL;
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bit = BIT(offset - FPC202_GPIO_P0_S0_OUT_A);
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}
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ret = fpc202_read(priv, reg);
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if (ret < 0)
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return ret;
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return !!(((u8)ret) & bit);
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}
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static int fpc202_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
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{
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if (fpc202_gpio_get_dir(offset) == GPIO_LINE_DIRECTION_OUT)
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return -EINVAL;
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return 0;
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}
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static int fpc202_gpio_direction_output(struct gpio_chip *chip, unsigned int offset,
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int value)
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{
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struct fpc202_priv *priv = gpiochip_get_data(chip);
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int ret;
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u8 val;
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if (fpc202_gpio_get_dir(offset) == GPIO_LINE_DIRECTION_IN)
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return -EINVAL;
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fpc202_gpio_set(chip, offset, value);
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ret = fpc202_read(priv, FPC202_REG_OUT_A_OUT_B);
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if (ret < 0)
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return ret;
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val = (u8)ret | BIT(offset - FPC202_GPIO_P0_S0_OUT_A);
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return fpc202_write(priv, FPC202_REG_OUT_A_OUT_B, val);
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}
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/*
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* Set the translation table entry associated with a port and device number.
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*
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* Each downstream port of the FPC202 has two fixed aliases corresponding to
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* device numbers 0 and 1. If one of these aliases is found in an incoming I2C
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* transfer, it will be translated to the address given by the corresponding
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* translation table entry.
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*/
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static int fpc202_write_dev_addr(struct fpc202_priv *priv, u32 port_id, int dev_num, u16 addr)
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{
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int ret, reg_mod, reg_aux;
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u8 val;
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guard(mutex)(&priv->reg_dev_lock);
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reg_mod = FPC202_REG_MOD_DEV(port_id, dev_num);
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reg_aux = FPC202_REG_AUX_DEV(port_id, dev_num);
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val = addr & 0x7f;
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ret = fpc202_write(priv, reg_mod, val);
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if (ret)
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return ret;
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/*
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* The FPC202 datasheet is unclear about the role of the AUX registers.
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* Empirically, writing to them as well seems to be necessary for
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* address translation to function properly.
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*/
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ret = fpc202_write(priv, reg_aux, val);
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priv->addr_caches[port_id][dev_num] = val;
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return ret;
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}
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static int fpc202_attach_addr(struct i2c_atr *atr, u32 chan_id,
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u16 addr, u16 alias)
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{
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struct fpc202_priv *priv = i2c_atr_get_driver_data(atr);
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dev_dbg(&priv->client->dev, "attaching address 0x%02x to alias 0x%02x\n", addr, alias);
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return fpc202_write_dev_addr(priv, chan_id, fpc202_dev_num_from_alias(alias), addr);
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}
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static void fpc202_detach_addr(struct i2c_atr *atr, u32 chan_id,
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u16 addr)
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{
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struct fpc202_priv *priv = i2c_atr_get_driver_data(atr);
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int dev_num, reg_mod, val;
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for (dev_num = 0; dev_num < 2; dev_num++) {
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reg_mod = FPC202_REG_MOD_DEV(chan_id, dev_num);
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mutex_lock(&priv->reg_dev_lock);
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val = priv->addr_caches[chan_id][dev_num];
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mutex_unlock(&priv->reg_dev_lock);
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if (val < 0) {
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dev_err(&priv->client->dev, "failed to read register 0x%x while detaching address 0x%02x\n",
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reg_mod, addr);
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return;
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}
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if (val == (addr & 0x7f)) {
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fpc202_write_dev_addr(priv, chan_id, dev_num, FPC202_REG_DEV_INVALID);
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return;
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}
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}
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}
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static const struct i2c_atr_ops fpc202_atr_ops = {
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.attach_addr = fpc202_attach_addr,
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.detach_addr = fpc202_detach_addr,
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};
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static int fpc202_probe_port(struct fpc202_priv *priv, struct device_node *i2c_handle, int port_id)
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{
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u16 aliases[FPC202_ALIASES_PER_PORT] = { };
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struct device *dev = &priv->client->dev;
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struct i2c_atr_adap_desc desc = { };
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int ret = 0;
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desc.chan_id = port_id;
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desc.parent = dev;
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desc.bus_handle = of_node_to_fwnode(i2c_handle);
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desc.num_aliases = FPC202_ALIASES_PER_PORT;
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fpc202_fill_alias_table(priv->client, aliases, port_id);
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desc.aliases = aliases;
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ret = i2c_atr_add_adapter(priv->atr, &desc);
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if (ret)
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return ret;
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set_bit(port_id, priv->probed_ports);
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ret = fpc202_write_dev_addr(priv, port_id, 0, FPC202_REG_DEV_INVALID);
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if (ret)
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return ret;
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return fpc202_write_dev_addr(priv, port_id, 1, FPC202_REG_DEV_INVALID);
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}
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static void fpc202_remove_port(struct fpc202_priv *priv, int port_id)
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{
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i2c_atr_del_adapter(priv->atr, port_id);
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clear_bit(port_id, priv->probed_ports);
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}
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static int fpc202_probe(struct i2c_client *client)
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{
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struct device *dev = &client->dev;
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struct device_node *i2c_handle;
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struct fpc202_priv *priv;
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int ret, port_id;
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priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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mutex_init(&priv->reg_dev_lock);
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priv->client = client;
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i2c_set_clientdata(client, priv);
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priv->en_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_HIGH);
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if (IS_ERR(priv->en_gpio)) {
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ret = PTR_ERR(priv->en_gpio);
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dev_err(dev, "failed to fetch enable GPIO! err %d\n", ret);
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goto destroy_mutex;
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}
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priv->gpio.label = "gpio-fpc202";
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priv->gpio.base = -1;
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priv->gpio.direction_input = fpc202_gpio_direction_input;
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priv->gpio.direction_output = fpc202_gpio_direction_output;
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priv->gpio.set = fpc202_gpio_set;
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priv->gpio.get = fpc202_gpio_get;
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priv->gpio.ngpio = FPC202_GPIO_COUNT;
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priv->gpio.parent = dev;
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priv->gpio.owner = THIS_MODULE;
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ret = gpiochip_add_data(&priv->gpio, priv);
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if (ret) {
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priv->gpio.parent = NULL;
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dev_err(dev, "failed to add gpiochip err %d\n", ret);
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goto disable_gpio;
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}
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priv->atr = i2c_atr_new(client->adapter, dev, &fpc202_atr_ops, 2);
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if (IS_ERR(priv->atr)) {
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ret = PTR_ERR(priv->atr);
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dev_err(dev, "failed to create i2c atr err %d\n", ret);
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goto disable_gpio;
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}
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i2c_atr_set_driver_data(priv->atr, priv);
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bitmap_zero(priv->probed_ports, FPC202_NUM_PORTS);
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for_each_child_of_node(dev->of_node, i2c_handle) {
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ret = of_property_read_u32(i2c_handle, "reg", &port_id);
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if (ret) {
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if (ret == -EINVAL)
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continue;
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dev_err(dev, "failed to read 'reg' property of child node, err %d\n", ret);
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goto unregister_chans;
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}
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if (port_id > FPC202_NUM_PORTS) {
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dev_err(dev, "port ID %d is out of range!\n", port_id);
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ret = -EINVAL;
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goto unregister_chans;
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}
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ret = fpc202_probe_port(priv, i2c_handle, port_id);
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if (ret) {
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dev_err(dev, "Failed to probe port %d, err %d\n", port_id, ret);
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goto unregister_chans;
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}
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}
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goto out;
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unregister_chans:
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for_each_set_bit(port_id, priv->probed_ports, FPC202_NUM_PORTS)
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fpc202_remove_port(priv, port_id);
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i2c_atr_delete(priv->atr);
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disable_gpio:
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fpc202_set_enable(priv, 0);
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gpiochip_remove(&priv->gpio);
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destroy_mutex:
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mutex_destroy(&priv->reg_dev_lock);
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out:
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return ret;
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}
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|
||||
static void fpc202_remove(struct i2c_client *client)
|
||||
{
|
||||
struct fpc202_priv *priv = i2c_get_clientdata(client);
|
||||
int port_id;
|
||||
|
||||
for_each_set_bit(port_id, priv->probed_ports, FPC202_NUM_PORTS)
|
||||
fpc202_remove_port(priv, port_id);
|
||||
|
||||
mutex_destroy(&priv->reg_dev_lock);
|
||||
|
||||
i2c_atr_delete(priv->atr);
|
||||
|
||||
fpc202_set_enable(priv, 0);
|
||||
gpiochip_remove(&priv->gpio);
|
||||
}
|
||||
|
||||
static const struct of_device_id fpc202_of_match[] = {
|
||||
{ .compatible = "ti,fpc202" },
|
||||
{}
|
||||
};
|
||||
MODULE_DEVICE_TABLE(of, fpc202_of_match);
|
||||
|
||||
static struct i2c_driver fpc202_driver = {
|
||||
.driver = {
|
||||
.name = "fpc202",
|
||||
.of_match_table = fpc202_of_match,
|
||||
},
|
||||
.probe = fpc202_probe,
|
||||
.remove = fpc202_remove,
|
||||
};
|
||||
|
||||
module_i2c_driver(fpc202_driver);
|
||||
|
||||
MODULE_AUTHOR("Romain Gantois <romain.gantois@bootlin.com>");
|
||||
MODULE_DESCRIPTION("TI FPC202 Dual Port Controller driver");
|
||||
MODULE_LICENSE("GPL");
|
||||
MODULE_IMPORT_NS("I2C_ATR");
|
||||
Loading…
Reference in New Issue
Block a user