diff options
Diffstat (limited to 'drivers/gpio')
| -rw-r--r-- | drivers/gpio/gpio-stp-xway.c | 333 |
1 files changed, 241 insertions, 92 deletions
diff --git a/drivers/gpio/gpio-stp-xway.c b/drivers/gpio/gpio-stp-xway.c index d674f1be237..e35096bf3cf 100644 --- a/drivers/gpio/gpio-stp-xway.c +++ b/drivers/gpio/gpio-stp-xway.c @@ -3,150 +3,299 @@ * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * - * Copyright (C) 2007 John Crispin <blogic@openwrt.org> + * Copyright (C) 2012 John Crispin <blogic@openwrt.org> * */ #include <linux/slab.h> #include <linux/init.h> -#include <linux/export.h> +#include <linux/module.h> #include <linux/types.h> -#include <linux/platform_device.h> +#include <linux/of_platform.h> #include <linux/mutex.h> -#include <linux/io.h> #include <linux/gpio.h> +#include <linux/io.h> +#include <linux/of_gpio.h> +#include <linux/clk.h> +#include <linux/err.h> #include <lantiq_soc.h> -#define LTQ_STP_CON0 0x00 -#define LTQ_STP_CON1 0x04 -#define LTQ_STP_CPU0 0x08 -#define LTQ_STP_CPU1 0x0C -#define LTQ_STP_AR 0x10 - -#define LTQ_STP_CON_SWU (1 << 31) -#define LTQ_STP_2HZ 0 -#define LTQ_STP_4HZ (1 << 23) -#define LTQ_STP_8HZ (2 << 23) -#define LTQ_STP_10HZ (3 << 23) -#define LTQ_STP_SPEED_MASK (0xf << 23) -#define LTQ_STP_UPD_FPI (1 << 31) -#define LTQ_STP_UPD_MASK (3 << 30) -#define LTQ_STP_ADSL_SRC (3 << 24) - -#define LTQ_STP_GROUP0 (1 << 0) - -#define LTQ_STP_RISING 0 -#define LTQ_STP_FALLING (1 << 26) -#define LTQ_STP_EDGE_MASK (1 << 26) - -#define ltq_stp_r32(reg) __raw_readl(ltq_stp_membase + reg) -#define ltq_stp_w32(val, reg) __raw_writel(val, ltq_stp_membase + reg) -#define ltq_stp_w32_mask(clear, set, reg) \ - ltq_w32((ltq_r32(ltq_stp_membase + reg) & ~(clear)) | (set), \ - ltq_stp_membase + (reg)) - -static int ltq_stp_shadow = 0xffff; -static void __iomem *ltq_stp_membase; - -static void ltq_stp_set(struct gpio_chip *chip, unsigned offset, int value) +/* + * The Serial To Parallel (STP) is found on MIPS based Lantiq socs. It is a + * peripheral controller used to drive external shift register cascades. At most + * 3 groups of 8 bits can be driven. The hardware is able to allow the DSL modem + * to drive the 2 LSBs of the cascade automatically. + */ + +/* control register 0 */ +#define XWAY_STP_CON0 0x00 +/* control register 1 */ +#define XWAY_STP_CON1 0x04 +/* data register 0 */ +#define XWAY_STP_CPU0 0x08 +/* data register 1 */ +#define XWAY_STP_CPU1 0x0C +/* access register */ +#define XWAY_STP_AR 0x10 + +/* software or hardware update select bit */ +#define XWAY_STP_CON_SWU BIT(31) + +/* automatic update rates */ +#define XWAY_STP_2HZ 0 +#define XWAY_STP_4HZ BIT(23) +#define XWAY_STP_8HZ BIT(24) +#define XWAY_STP_10HZ (BIT(24) | BIT(23)) +#define XWAY_STP_SPEED_MASK (0xf << 23) + +/* clock source for automatic update */ +#define XWAY_STP_UPD_FPI BIT(31) +#define XWAY_STP_UPD_MASK (BIT(31) | BIT(30)) + +/* let the adsl core drive the 2 LSBs */ +#define XWAY_STP_ADSL_SHIFT 24 +#define XWAY_STP_ADSL_MASK 0x3 + +/* 2 groups of 3 bits can be driven by the phys */ +#define XWAY_STP_PHY_MASK 0x3 +#define XWAY_STP_PHY1_SHIFT 27 +#define XWAY_STP_PHY2_SHIFT 15 + +/* STP has 3 groups of 8 bits */ +#define XWAY_STP_GROUP0 BIT(0) +#define XWAY_STP_GROUP1 BIT(1) +#define XWAY_STP_GROUP2 BIT(2) +#define XWAY_STP_GROUP_MASK (0x7) + +/* Edge configuration bits */ +#define XWAY_STP_FALLING BIT(26) +#define XWAY_STP_EDGE_MASK BIT(26) + +#define xway_stp_r32(m, reg) __raw_readl(m + reg) +#define xway_stp_w32(m, val, reg) __raw_writel(val, m + reg) +#define xway_stp_w32_mask(m, clear, set, reg) \ + ltq_w32((ltq_r32(m + reg) & ~(clear)) | (set), \ + m + reg) + +struct xway_stp { + struct gpio_chip gc; + void __iomem *virt; + u32 edge; /* rising or falling edge triggered shift register */ + u16 shadow; /* shadow the shift registers state */ + u8 groups; /* we can drive 1-3 groups of 8bit each */ + u8 dsl; /* the 2 LSBs can be driven by the dsl core */ + u8 phy1; /* 3 bits can be driven by phy1 */ + u8 phy2; /* 3 bits can be driven by phy2 */ + u8 reserved; /* mask out the hw driven bits in gpio_request */ +}; + +/** + * xway_stp_set() - gpio_chip->set - set gpios. + * @gc: Pointer to gpio_chip device structure. + * @gpio: GPIO signal number. + * @val: Value to be written to specified signal. + * + * Set the shadow value and call ltq_ebu_apply. + */ +static void xway_stp_set(struct gpio_chip *gc, unsigned gpio, int val) { - if (value) - ltq_stp_shadow |= (1 << offset); + struct xway_stp *chip = + container_of(gc, struct xway_stp, gc); + + if (val) + chip->shadow |= BIT(gpio); else - ltq_stp_shadow &= ~(1 << offset); - ltq_stp_w32(ltq_stp_shadow, LTQ_STP_CPU0); + chip->shadow &= ~BIT(gpio); + xway_stp_w32(chip->virt, chip->shadow, XWAY_STP_CPU0); + xway_stp_w32_mask(chip->virt, 0, XWAY_STP_CON_SWU, XWAY_STP_CON0); } -static int ltq_stp_direction_output(struct gpio_chip *chip, unsigned offset, - int value) +/** + * xway_stp_dir_out() - gpio_chip->dir_out - set gpio direction. + * @gc: Pointer to gpio_chip device structure. + * @gpio: GPIO signal number. + * @val: Value to be written to specified signal. + * + * Same as xway_stp_set, always returns 0. + */ +static int xway_stp_dir_out(struct gpio_chip *gc, unsigned gpio, int val) { - ltq_stp_set(chip, offset, value); + xway_stp_set(gc, gpio, val); return 0; } -static struct gpio_chip ltq_stp_chip = { - .label = "ltq_stp", - .direction_output = ltq_stp_direction_output, - .set = ltq_stp_set, - .base = 48, - .ngpio = 24, - .can_sleep = 1, - .owner = THIS_MODULE, -}; +/** + * xway_stp_request() - gpio_chip->request + * @gc: Pointer to gpio_chip device structure. + * @gpio: GPIO signal number. + * + * We mask out the HW driven pins + */ +static int xway_stp_request(struct gpio_chip *gc, unsigned gpio) +{ + struct xway_stp *chip = + container_of(gc, struct xway_stp, gc); + + if ((gpio < 8) && (chip->reserved & BIT(gpio))) { + dev_err(gc->dev, "GPIO %d is driven by hardware\n", gpio); + return -ENODEV; + } -static int ltq_stp_hw_init(void) + return 0; +} + +/** + * xway_stp_hw_init() - Configure the STP unit and enable the clock gate + * @virt: pointer to the remapped register range + */ +static int xway_stp_hw_init(struct xway_stp *chip) { /* sane defaults */ - ltq_stp_w32(0, LTQ_STP_AR); - ltq_stp_w32(0, LTQ_STP_CPU0); - ltq_stp_w32(0, LTQ_STP_CPU1); - ltq_stp_w32(LTQ_STP_CON_SWU, LTQ_STP_CON0); - ltq_stp_w32(0, LTQ_STP_CON1); + xway_stp_w32(chip->virt, 0, XWAY_STP_AR); + xway_stp_w32(chip->virt, 0, XWAY_STP_CPU0); + xway_stp_w32(chip->virt, 0, XWAY_STP_CPU1); + xway_stp_w32(chip->virt, XWAY_STP_CON_SWU, XWAY_STP_CON0); + xway_stp_w32(chip->virt, 0, XWAY_STP_CON1); - /* rising or falling edge */ - ltq_stp_w32_mask(LTQ_STP_EDGE_MASK, LTQ_STP_FALLING, LTQ_STP_CON0); + /* apply edge trigger settings for the shift register */ + xway_stp_w32_mask(chip->virt, XWAY_STP_EDGE_MASK, + chip->edge, XWAY_STP_CON0); - /* per default stp 15-0 are set */ - ltq_stp_w32_mask(0, LTQ_STP_GROUP0, LTQ_STP_CON1); + /* apply led group settings */ + xway_stp_w32_mask(chip->virt, XWAY_STP_GROUP_MASK, + chip->groups, XWAY_STP_CON1); - /* stp are update periodically by the FPI bus */ - ltq_stp_w32_mask(LTQ_STP_UPD_MASK, LTQ_STP_UPD_FPI, LTQ_STP_CON1); + /* tell the hardware which pins are controlled by the dsl modem */ + xway_stp_w32_mask(chip->virt, + XWAY_STP_ADSL_MASK << XWAY_STP_ADSL_SHIFT, + chip->dsl << XWAY_STP_ADSL_SHIFT, + XWAY_STP_CON0); - /* set stp update speed */ - ltq_stp_w32_mask(LTQ_STP_SPEED_MASK, LTQ_STP_8HZ, LTQ_STP_CON1); + /* tell the hardware which pins are controlled by the phys */ + xway_stp_w32_mask(chip->virt, + XWAY_STP_PHY_MASK << XWAY_STP_PHY1_SHIFT, + chip->phy1 << XWAY_STP_PHY1_SHIFT, + XWAY_STP_CON0); + xway_stp_w32_mask(chip->virt, + XWAY_STP_PHY_MASK << XWAY_STP_PHY2_SHIFT, + chip->phy2 << XWAY_STP_PHY2_SHIFT, + XWAY_STP_CON1); - /* tell the hardware that pin (led) 0 and 1 are controlled - * by the dsl arc + /* mask out the hw driven bits in gpio_request */ + chip->reserved = (chip->phy2 << 5) | (chip->phy1 << 2) | chip->dsl; + + /* + * if we have pins that are driven by hw, we need to tell the stp what + * clock to use as a timer. */ - ltq_stp_w32_mask(0, LTQ_STP_ADSL_SRC, LTQ_STP_CON0); + if (chip->reserved) + xway_stp_w32_mask(chip->virt, XWAY_STP_UPD_MASK, + XWAY_STP_UPD_FPI, XWAY_STP_CON1); - ltq_pmu_enable(PMU_LED); return 0; } -static int __devinit ltq_stp_probe(struct platform_device *pdev) +static int __devinit xway_stp_probe(struct platform_device *pdev) { struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + const __be32 *shadow, *groups, *dsl, *phy; + struct xway_stp *chip; + struct clk *clk; int ret = 0; - if (!res) - return -ENOENT; - res = devm_request_mem_region(&pdev->dev, res->start, - resource_size(res), dev_name(&pdev->dev)); if (!res) { - dev_err(&pdev->dev, "failed to request STP memory\n"); - return -EBUSY; + dev_err(&pdev->dev, "failed to request STP resource\n"); + return -ENOENT; } - ltq_stp_membase = devm_ioremap_nocache(&pdev->dev, res->start, - resource_size(res)); - if (!ltq_stp_membase) { + + chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + chip->virt = devm_request_and_ioremap(&pdev->dev, res); + if (!chip->virt) { dev_err(&pdev->dev, "failed to remap STP memory\n"); return -ENOMEM; } - ret = gpiochip_add(<q_stp_chip); + chip->gc.dev = &pdev->dev; + chip->gc.label = "stp-xway"; + chip->gc.direction_output = xway_stp_dir_out; + chip->gc.set = xway_stp_set; + chip->gc.request = xway_stp_request; + chip->gc.base = -1; + chip->gc.owner = THIS_MODULE; + + /* store the shadow value if one was passed by the devicetree */ + shadow = of_get_property(pdev->dev.of_node, "lantiq,shadow", NULL); + if (shadow) + chip->shadow = be32_to_cpu(*shadow); + + /* find out which gpio groups should be enabled */ + groups = of_get_property(pdev->dev.of_node, "lantiq,groups", NULL); + if (groups) + chip->groups = be32_to_cpu(*groups) & XWAY_STP_GROUP_MASK; + else + chip->groups = XWAY_STP_GROUP0; + chip->gc.ngpio = fls(chip->groups) * 8; + + /* find out which gpios are controlled by the dsl core */ + dsl = of_get_property(pdev->dev.of_node, "lantiq,dsl", NULL); + if (dsl) + chip->dsl = be32_to_cpu(*dsl) & XWAY_STP_ADSL_MASK; + + /* find out which gpios are controlled by the phys */ + if (of_machine_is_compatible("lantiq,ar9") || + of_machine_is_compatible("lantiq,gr9") || + of_machine_is_compatible("lantiq,vr9")) { + phy = of_get_property(pdev->dev.of_node, "lantiq,phy1", NULL); + if (phy) + chip->phy1 = be32_to_cpu(*phy) & XWAY_STP_PHY_MASK; + phy = of_get_property(pdev->dev.of_node, "lantiq,phy2", NULL); + if (phy) + chip->phy2 = be32_to_cpu(*phy) & XWAY_STP_PHY_MASK; + } + + /* check which edge trigger we should use, default to a falling edge */ + if (!of_find_property(pdev->dev.of_node, "lantiq,rising", NULL)) + chip->edge = XWAY_STP_FALLING; + + clk = clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) { + dev_err(&pdev->dev, "Failed to get clock\n"); + return PTR_ERR(clk); + } + clk_enable(clk); + + ret = xway_stp_hw_init(chip); if (!ret) - ret = ltq_stp_hw_init(); + ret = gpiochip_add(&chip->gc); + + if (!ret) + dev_info(&pdev->dev, "Init done\n"); return ret; } -static struct platform_driver ltq_stp_driver = { - .probe = ltq_stp_probe, +static const struct of_device_id xway_stp_match[] = { + { .compatible = "lantiq,gpio-stp-xway" }, + {}, +}; +MODULE_DEVICE_TABLE(of, xway_stp_match); + +static struct platform_driver xway_stp_driver = { + .probe = xway_stp_probe, .driver = { - .name = "ltq_stp", + .name = "gpio-stp-xway", .owner = THIS_MODULE, + .of_match_table = xway_stp_match, }, }; -int __init ltq_stp_init(void) +int __init xway_stp_init(void) { - int ret = platform_driver_register(<q_stp_driver); - - if (ret) - pr_info("ltq_stp: error registering platfom driver"); - return ret; + return platform_driver_register(&xway_stp_driver); } -postcore_initcall(ltq_stp_init); +subsys_initcall(xway_stp_init); |