/* * Copyright (C) 2025 Michael Brown . * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that 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, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301, USA. * * You can also choose to distribute this program under the terms of * the Unmodified Binary Distribution Licence (as given in the file * COPYING.UBDL), provided that you have satisfied its requirements. */ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); #include #include #include #include #include #include #include "dwgpio.h" /** @file * * Synopsys DesignWare GPIO driver * */ /****************************************************************************** * * GPIO port group * ****************************************************************************** */ /** * Probe port group * * @v dt Devicetree device * @v offset Starting node offset * @ret rc Return status code */ static int dwgpio_group_probe ( struct dt_device *dt, unsigned int offset ) { struct dwgpio_group *group; int rc; /* Allocate and initialise structure */ group = zalloc ( sizeof ( *group ) ); if ( ! group ) { rc = -ENOMEM; goto err_alloc; } dt_set_drvdata ( dt, group ); /* Map registers */ group->regs = dt_ioremap ( dt, offset, 0, 0 ); if ( ! group->regs ) { rc = -ENODEV; goto err_ioremap; } /* Probe child ports */ if ( ( rc = dt_probe_children ( dt, offset ) ) != 0 ) goto err_children; return 0; dt_remove_children ( dt ); err_children: iounmap ( group->regs ); err_ioremap: free ( group ); err_alloc: return rc; } /** * Remove port group * * @v dt Devicetree device */ static void dwgpio_group_remove ( struct dt_device *dt ) { struct dwgpio_group *group = dt_get_drvdata ( dt ); /* Remove child ports */ dt_remove_children ( dt ); /* Unmap registers */ iounmap ( group->regs ); /* Free device */ free ( group ); } /** DesignWare GPIO port group compatible model identifiers */ static const char * dwgpio_group_ids[] = { "snps,dw-apb-gpio", }; /** DesignWare GPIO port group devicetree driver */ struct dt_driver dwgpio_group_driver __dt_driver = { .name = "dwgpio-group", .ids = dwgpio_group_ids, .id_count = ( sizeof ( dwgpio_group_ids ) / sizeof ( dwgpio_group_ids[0] ) ), .probe = dwgpio_group_probe, .remove = dwgpio_group_remove, }; /****************************************************************************** * * GPIO port * ****************************************************************************** */ /** * Dump GPIO port status * * @v dwgpio DesignWare GPIO port */ static inline void dwgpio_dump ( struct dwgpio *dwgpio ) { DBGC2 ( dwgpio, "DWGPIO %s dr %#08x ddr %#08x ctl %#08x\n", dwgpio->name, readl ( dwgpio->swport + DWGPIO_SWPORT_DR ), readl ( dwgpio->swport + DWGPIO_SWPORT_DDR ), readl ( dwgpio->swport + DWGPIO_SWPORT_CTL ) ); } /** * Get current GPIO input value * * @v gpios GPIO controller * @v gpio GPIO pin * @ret active Pin is in the active state */ static int dwgpio_in ( struct gpios *gpios, struct gpio *gpio ) { struct dwgpio *dwgpio = gpios->priv; uint32_t ext; /* Read external port status */ ext = readl ( dwgpio->ext ); return ( ( ( ext >> gpio->index ) ^ gpio->config ) & 1 ); } /** * Set current GPIO output value * * @v gpios GPIO controller * @v gpio GPIO pin * @v active Set pin to active state */ static void dwgpio_out ( struct gpios *gpios, struct gpio *gpio, int active ) { struct dwgpio *dwgpio = gpios->priv; uint32_t mask = ( 1UL << gpio->index ); uint32_t dr; /* Update data register */ dr = readl ( dwgpio->swport + DWGPIO_SWPORT_DR ); dr &= ~mask; if ( ( ( !! active ) ^ gpio->config ) & 1 ) dr |= mask; writel ( dr, ( dwgpio->swport + DWGPIO_SWPORT_DR ) ); dwgpio_dump ( dwgpio ); } /** * Configure GPIO pin * * @v gpios GPIO controller * @v gpio GPIO pin * @v config Configuration * @ret rc Return status code */ static int dwgpio_config ( struct gpios *gpios, struct gpio *gpio, unsigned int config ) { struct dwgpio *dwgpio = gpios->priv; uint32_t mask = ( 1UL << gpio->index ); uint32_t ddr; uint32_t ctl; /* Update data direction and control registers */ ddr = readl ( dwgpio->swport + DWGPIO_SWPORT_DDR ); ctl = readl ( dwgpio->swport + DWGPIO_SWPORT_CTL ); ctl &= ~mask; ddr &= ~mask; if ( config & GPIO_CFG_OUTPUT ) ddr |= mask; writel ( ctl, ( dwgpio->swport + DWGPIO_SWPORT_CTL ) ); writel ( ddr, ( dwgpio->swport + DWGPIO_SWPORT_DDR ) ); dwgpio_dump ( dwgpio ); return 0; } /** GPIO operations */ static struct gpio_operations dwgpio_operations = { .in = dwgpio_in, .out = dwgpio_out, .config = dwgpio_config, }; /** * Probe port * * @v dt Devicetree device * @v offset Starting node offset * @ret rc Return status code */ static int dwgpio_probe ( struct dt_device *dt, unsigned int offset ) { struct dt_device *parent; struct dwgpio_group *group; struct dwgpio *dwgpio; struct gpios *gpios; uint32_t count; uint64_t port; int rc; /* Get number of GPIOs */ if ( ( rc = fdt_u32 ( &sysfdt, offset, "nr-gpios-snps", &count ) ) != 0 ) { goto err_count; } assert ( count <= DWGPIO_MAX_COUNT ); /* Allocate and initialise device */ gpios = alloc_gpios ( count, sizeof ( *dwgpio ) ); if ( ! gpios ) { rc = -ENOMEM; goto err_alloc; } dt_set_drvdata ( dt, gpios ); gpios->dev = &dt->dev; gpios_init ( gpios, &dwgpio_operations ); dwgpio = gpios->priv; dwgpio->name = dt->name; /* Identify group */ parent = dt_parent ( dt ); if ( parent->driver != &dwgpio_group_driver ) { DBGC ( dwgpio, "DWGPIO %s has invalid parent %s\n", dwgpio->name, parent->name ); rc = -EINVAL; goto err_parent; } group = dt_get_drvdata ( parent ); /* Identify port */ if ( ( rc = fdt_reg ( &sysfdt, offset, &port ) ) != 0 ) { DBGC ( dwgpio, "DWGPIO %s could not get port number: %s\n", dwgpio->name, strerror ( rc ) ); goto err_port; } dwgpio->port = port; DBGC ( dwgpio, "DWGPIO %s is %s port %d (%d GPIOs)\n", dwgpio->name, parent->name, dwgpio->port, gpios->count ); /* Map registers */ dwgpio->swport = ( group->regs + DWGPIO_SWPORT ( port ) ); dwgpio->ext = ( group->regs + DWGPIO_EXT_PORT ( port ) ); dwgpio_dump ( dwgpio ); /* Record original register values */ dwgpio->dr = readl ( dwgpio->swport + DWGPIO_SWPORT_DR ); dwgpio->ddr = readl ( dwgpio->swport + DWGPIO_SWPORT_DDR ); dwgpio->ctl = readl ( dwgpio->swport + DWGPIO_SWPORT_CTL ); /* Register GPIO controller */ if ( ( rc = gpios_register ( gpios ) ) != 0 ) { DBGC ( dwgpio, "DWGPIO %s could not register: %s\n", dwgpio->name, strerror ( rc ) ); goto err_register; } return 0; gpios_unregister ( gpios ); err_register: err_port: err_parent: gpios_nullify ( gpios ); gpios_put ( gpios ); err_alloc: err_count: return rc; } /** * Remove port * * @v dt Devicetree device */ static void dwgpio_remove ( struct dt_device *dt ) { struct gpios *gpios = dt_get_drvdata ( dt ); struct dwgpio *dwgpio = gpios->priv; /* Unregister GPIO controller */ gpios_unregister ( gpios ); /* Restore original register values */ writel ( dwgpio->ctl, ( dwgpio->swport + DWGPIO_SWPORT_CTL ) ); writel ( dwgpio->ddr, ( dwgpio->swport + DWGPIO_SWPORT_DDR ) ); writel ( dwgpio->dr, ( dwgpio->swport + DWGPIO_SWPORT_DR ) ); /* Free GPIO device */ gpios_nullify ( gpios ); gpios_put ( gpios ); } /** DesignWare GPIO port compatible model identifiers */ static const char * dwgpio_ids[] = { "snps,dw-apb-gpio-port", }; /** DesignWare GPIO port devicetree driver */ struct dt_driver dwgpio_driver __dt_driver = { .name = "dwgpio", .ids = dwgpio_ids, .id_count = ( sizeof ( dwgpio_ids ) / sizeof ( dwgpio_ids[0] ) ), .probe = dwgpio_probe, .remove = dwgpio_remove, };