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![Aleksander Jan Bajkowski](/assets/img/avatar_default.png)
Ar10 (xr300) has 3 and grx390 (xrx330) has 4 built-in GPHY. PHY LEDs are connected via STP. STP is a peripheral controller used to drive external shift register cascades. The hardware is able to allow the GPHY to drive some GPIO of the cascade automatically.This patch allows for this on ar10 and grx390. Tested on D-Link DWR-966 with OpenWRT. Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl> Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
340 lines
9.6 KiB
C
340 lines
9.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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*
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* Copyright (C) 2012 John Crispin <john@phrozen.org>
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*/
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#include <linux/slab.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/of_platform.h>
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#include <linux/mutex.h>
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#include <linux/gpio/driver.h>
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#include <linux/io.h>
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#include <linux/clk.h>
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#include <linux/err.h>
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/*
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* The Serial To Parallel (STP) is found on MIPS based Lantiq socs. It is a
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* peripheral controller used to drive external shift register cascades. At most
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* 3 groups of 8 bits can be driven. The hardware is able to allow the DSL modem
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* to drive the 2 LSBs of the cascade automatically.
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*/
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/* control register 0 */
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#define XWAY_STP_CON0 0x00
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/* control register 1 */
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#define XWAY_STP_CON1 0x04
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/* data register 0 */
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#define XWAY_STP_CPU0 0x08
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/* data register 1 */
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#define XWAY_STP_CPU1 0x0C
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/* access register */
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#define XWAY_STP_AR 0x10
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/* software or hardware update select bit */
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#define XWAY_STP_CON_SWU BIT(31)
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/* automatic update rates */
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#define XWAY_STP_2HZ 0
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#define XWAY_STP_4HZ BIT(23)
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#define XWAY_STP_8HZ BIT(24)
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#define XWAY_STP_10HZ (BIT(24) | BIT(23))
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#define XWAY_STP_SPEED_MASK (BIT(23) | BIT(24) | BIT(25) | BIT(26) | BIT(27))
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#define XWAY_STP_FPIS_VALUE BIT(21)
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#define XWAY_STP_FPIS_MASK (BIT(20) | BIT(21))
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/* clock source for automatic update */
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#define XWAY_STP_UPD_FPI BIT(31)
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#define XWAY_STP_UPD_MASK (BIT(31) | BIT(30))
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/* let the adsl core drive the 2 LSBs */
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#define XWAY_STP_ADSL_SHIFT 24
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#define XWAY_STP_ADSL_MASK 0x3
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/* 2 groups of 3 bits can be driven by the phys */
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#define XWAY_STP_PHY_MASK 0x7
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#define XWAY_STP_PHY1_SHIFT 27
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#define XWAY_STP_PHY2_SHIFT 3
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#define XWAY_STP_PHY3_SHIFT 6
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#define XWAY_STP_PHY4_SHIFT 15
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/* STP has 3 groups of 8 bits */
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#define XWAY_STP_GROUP0 BIT(0)
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#define XWAY_STP_GROUP1 BIT(1)
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#define XWAY_STP_GROUP2 BIT(2)
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#define XWAY_STP_GROUP_MASK (0x7)
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/* Edge configuration bits */
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#define XWAY_STP_FALLING BIT(26)
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#define XWAY_STP_EDGE_MASK BIT(26)
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#define xway_stp_r32(m, reg) __raw_readl(m + reg)
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#define xway_stp_w32(m, val, reg) __raw_writel(val, m + reg)
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#define xway_stp_w32_mask(m, clear, set, reg) \
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xway_stp_w32(m, (xway_stp_r32(m, reg) & ~(clear)) | (set), reg)
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struct xway_stp {
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struct gpio_chip gc;
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void __iomem *virt;
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u32 edge; /* rising or falling edge triggered shift register */
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u32 shadow; /* shadow the shift registers state */
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u8 groups; /* we can drive 1-3 groups of 8bit each */
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u8 dsl; /* the 2 LSBs can be driven by the dsl core */
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u8 phy1; /* 3 bits can be driven by phy1 */
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u8 phy2; /* 3 bits can be driven by phy2 */
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u8 phy3; /* 3 bits can be driven by phy3 */
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u8 phy4; /* 3 bits can be driven by phy4 */
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u8 reserved; /* mask out the hw driven bits in gpio_request */
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};
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/**
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* xway_stp_get() - gpio_chip->get - get gpios.
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* @gc: Pointer to gpio_chip device structure.
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* @gpio: GPIO signal number.
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*
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* Gets the shadow value.
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*/
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static int xway_stp_get(struct gpio_chip *gc, unsigned int gpio)
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{
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struct xway_stp *chip = gpiochip_get_data(gc);
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return (xway_stp_r32(chip->virt, XWAY_STP_CPU0) & BIT(gpio));
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}
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/**
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* xway_stp_set() - gpio_chip->set - set gpios.
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* @gc: Pointer to gpio_chip device structure.
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* @gpio: GPIO signal number.
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* @val: Value to be written to specified signal.
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*
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* Set the shadow value and call ltq_ebu_apply.
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*/
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static void xway_stp_set(struct gpio_chip *gc, unsigned gpio, int val)
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{
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struct xway_stp *chip = gpiochip_get_data(gc);
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if (val)
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chip->shadow |= BIT(gpio);
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else
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chip->shadow &= ~BIT(gpio);
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xway_stp_w32(chip->virt, chip->shadow, XWAY_STP_CPU0);
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if (!chip->reserved)
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xway_stp_w32_mask(chip->virt, 0, XWAY_STP_CON_SWU, XWAY_STP_CON0);
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}
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/**
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* xway_stp_dir_out() - gpio_chip->dir_out - set gpio direction.
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* @gc: Pointer to gpio_chip device structure.
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* @gpio: GPIO signal number.
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* @val: Value to be written to specified signal.
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*
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* Same as xway_stp_set, always returns 0.
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*/
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static int xway_stp_dir_out(struct gpio_chip *gc, unsigned gpio, int val)
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{
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xway_stp_set(gc, gpio, val);
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return 0;
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}
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/**
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* xway_stp_request() - gpio_chip->request
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* @gc: Pointer to gpio_chip device structure.
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* @gpio: GPIO signal number.
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*
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* We mask out the HW driven pins
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*/
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static int xway_stp_request(struct gpio_chip *gc, unsigned gpio)
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{
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struct xway_stp *chip = gpiochip_get_data(gc);
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if ((gpio < 8) && (chip->reserved & BIT(gpio))) {
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dev_err(gc->parent, "GPIO %d is driven by hardware\n", gpio);
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return -ENODEV;
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}
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return 0;
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}
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/**
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* xway_stp_hw_init() - Configure the STP unit and enable the clock gate
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* @chip: Pointer to the xway_stp chip structure
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*/
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static void xway_stp_hw_init(struct xway_stp *chip)
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{
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/* sane defaults */
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xway_stp_w32(chip->virt, 0, XWAY_STP_AR);
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xway_stp_w32(chip->virt, 0, XWAY_STP_CPU0);
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xway_stp_w32(chip->virt, 0, XWAY_STP_CPU1);
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xway_stp_w32(chip->virt, XWAY_STP_CON_SWU, XWAY_STP_CON0);
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xway_stp_w32(chip->virt, 0, XWAY_STP_CON1);
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/* apply edge trigger settings for the shift register */
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xway_stp_w32_mask(chip->virt, XWAY_STP_EDGE_MASK,
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chip->edge, XWAY_STP_CON0);
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/* apply led group settings */
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xway_stp_w32_mask(chip->virt, XWAY_STP_GROUP_MASK,
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chip->groups, XWAY_STP_CON1);
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/* tell the hardware which pins are controlled by the dsl modem */
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xway_stp_w32_mask(chip->virt,
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XWAY_STP_ADSL_MASK << XWAY_STP_ADSL_SHIFT,
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chip->dsl << XWAY_STP_ADSL_SHIFT,
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XWAY_STP_CON0);
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/* tell the hardware which pins are controlled by the phys */
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xway_stp_w32_mask(chip->virt,
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XWAY_STP_PHY_MASK << XWAY_STP_PHY1_SHIFT,
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chip->phy1 << XWAY_STP_PHY1_SHIFT,
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XWAY_STP_CON0);
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xway_stp_w32_mask(chip->virt,
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XWAY_STP_PHY_MASK << XWAY_STP_PHY2_SHIFT,
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chip->phy2 << XWAY_STP_PHY2_SHIFT,
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XWAY_STP_CON1);
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if (of_machine_is_compatible("lantiq,grx390")
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|| of_machine_is_compatible("lantiq,ar10")) {
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xway_stp_w32_mask(chip->virt,
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XWAY_STP_PHY_MASK << XWAY_STP_PHY3_SHIFT,
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chip->phy3 << XWAY_STP_PHY3_SHIFT,
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XWAY_STP_CON1);
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}
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if (of_machine_is_compatible("lantiq,grx390")) {
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xway_stp_w32_mask(chip->virt,
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XWAY_STP_PHY_MASK << XWAY_STP_PHY4_SHIFT,
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chip->phy4 << XWAY_STP_PHY4_SHIFT,
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XWAY_STP_CON1);
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}
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/* mask out the hw driven bits in gpio_request */
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chip->reserved = (chip->phy4 << 11) | (chip->phy3 << 8) | (chip->phy2 << 5)
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| (chip->phy1 << 2) | chip->dsl;
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/*
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* if we have pins that are driven by hw, we need to tell the stp what
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* clock to use as a timer.
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*/
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if (chip->reserved) {
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xway_stp_w32_mask(chip->virt, XWAY_STP_UPD_MASK,
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XWAY_STP_UPD_FPI, XWAY_STP_CON1);
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xway_stp_w32_mask(chip->virt, XWAY_STP_SPEED_MASK,
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XWAY_STP_10HZ, XWAY_STP_CON1);
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xway_stp_w32_mask(chip->virt, XWAY_STP_FPIS_MASK,
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XWAY_STP_FPIS_VALUE, XWAY_STP_CON1);
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}
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}
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static int xway_stp_probe(struct platform_device *pdev)
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{
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u32 shadow, groups, dsl, phy;
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struct xway_stp *chip;
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struct clk *clk;
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int ret = 0;
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chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
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if (!chip)
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return -ENOMEM;
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chip->virt = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(chip->virt))
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return PTR_ERR(chip->virt);
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chip->gc.parent = &pdev->dev;
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chip->gc.label = "stp-xway";
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chip->gc.direction_output = xway_stp_dir_out;
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chip->gc.get = xway_stp_get;
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chip->gc.set = xway_stp_set;
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chip->gc.request = xway_stp_request;
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chip->gc.base = -1;
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chip->gc.owner = THIS_MODULE;
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/* store the shadow value if one was passed by the devicetree */
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if (!of_property_read_u32(pdev->dev.of_node, "lantiq,shadow", &shadow))
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chip->shadow = shadow;
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/* find out which gpio groups should be enabled */
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if (!of_property_read_u32(pdev->dev.of_node, "lantiq,groups", &groups))
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chip->groups = groups & XWAY_STP_GROUP_MASK;
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else
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chip->groups = XWAY_STP_GROUP0;
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chip->gc.ngpio = fls(chip->groups) * 8;
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/* find out which gpios are controlled by the dsl core */
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if (!of_property_read_u32(pdev->dev.of_node, "lantiq,dsl", &dsl))
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chip->dsl = dsl & XWAY_STP_ADSL_MASK;
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/* find out which gpios are controlled by the phys */
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if (of_machine_is_compatible("lantiq,ar9") ||
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of_machine_is_compatible("lantiq,gr9") ||
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of_machine_is_compatible("lantiq,vr9") ||
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of_machine_is_compatible("lantiq,ar10") ||
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of_machine_is_compatible("lantiq,grx390")) {
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if (!of_property_read_u32(pdev->dev.of_node, "lantiq,phy1", &phy))
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chip->phy1 = phy & XWAY_STP_PHY_MASK;
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if (!of_property_read_u32(pdev->dev.of_node, "lantiq,phy2", &phy))
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chip->phy2 = phy & XWAY_STP_PHY_MASK;
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}
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if (of_machine_is_compatible("lantiq,ar10") ||
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of_machine_is_compatible("lantiq,grx390")) {
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if (!of_property_read_u32(pdev->dev.of_node, "lantiq,phy3", &phy))
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chip->phy3 = phy & XWAY_STP_PHY_MASK;
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}
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if (of_machine_is_compatible("lantiq,grx390")) {
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if (!of_property_read_u32(pdev->dev.of_node, "lantiq,phy4", &phy))
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chip->phy4 = phy & XWAY_STP_PHY_MASK;
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}
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/* check which edge trigger we should use, default to a falling edge */
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if (!of_find_property(pdev->dev.of_node, "lantiq,rising", NULL))
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chip->edge = XWAY_STP_FALLING;
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clk = devm_clk_get(&pdev->dev, NULL);
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if (IS_ERR(clk)) {
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dev_err(&pdev->dev, "Failed to get clock\n");
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return PTR_ERR(clk);
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}
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ret = clk_prepare_enable(clk);
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if (ret)
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return ret;
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xway_stp_hw_init(chip);
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ret = devm_gpiochip_add_data(&pdev->dev, &chip->gc, chip);
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if (ret) {
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clk_disable_unprepare(clk);
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return ret;
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}
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dev_info(&pdev->dev, "Init done\n");
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return 0;
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}
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static const struct of_device_id xway_stp_match[] = {
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{ .compatible = "lantiq,gpio-stp-xway" },
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{},
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};
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MODULE_DEVICE_TABLE(of, xway_stp_match);
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static struct platform_driver xway_stp_driver = {
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.probe = xway_stp_probe,
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.driver = {
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.name = "gpio-stp-xway",
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.of_match_table = xway_stp_match,
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},
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};
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static int __init xway_stp_init(void)
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{
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return platform_driver_register(&xway_stp_driver);
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}
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subsys_initcall(xway_stp_init);
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