/* * Marvell EBU SoC Device Bus Controller * (memory controller for NOR/NAND/SRAM/FPGA devices) * * Copyright (C) 2013-2014 Marvell * * 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 version 2 of the License. * * 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, see <http://www.gnu.org/licenses/>. * */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/err.h> #include <linux/io.h> #include <linux/clk.h> #include <linux/mbus.h> #include <linux/of_platform.h> #include <linux/of_address.h> #include <linux/platform_device.h> /* Register definitions */ #define ARMADA_DEV_WIDTH_SHIFT 30 #define ARMADA_BADR_SKEW_SHIFT 28 #define ARMADA_RD_HOLD_SHIFT 23 #define ARMADA_ACC_NEXT_SHIFT 17 #define ARMADA_RD_SETUP_SHIFT 12 #define ARMADA_ACC_FIRST_SHIFT 6 #define ARMADA_SYNC_ENABLE_SHIFT 24 #define ARMADA_WR_HIGH_SHIFT 16 #define ARMADA_WR_LOW_SHIFT 8 #define ARMADA_READ_PARAM_OFFSET 0x0 #define ARMADA_WRITE_PARAM_OFFSET 0x4 #define ORION_RESERVED (0x2 << 30) #define ORION_BADR_SKEW_SHIFT 28 #define ORION_WR_HIGH_EXT_BIT BIT(27) #define ORION_WR_HIGH_EXT_MASK 0x8 #define ORION_WR_LOW_EXT_BIT BIT(26) #define ORION_WR_LOW_EXT_MASK 0x8 #define ORION_ALE_WR_EXT_BIT BIT(25) #define ORION_ALE_WR_EXT_MASK 0x8 #define ORION_ACC_NEXT_EXT_BIT BIT(24) #define ORION_ACC_NEXT_EXT_MASK 0x10 #define ORION_ACC_FIRST_EXT_BIT BIT(23) #define ORION_ACC_FIRST_EXT_MASK 0x10 #define ORION_TURN_OFF_EXT_BIT BIT(22) #define ORION_TURN_OFF_EXT_MASK 0x8 #define ORION_DEV_WIDTH_SHIFT 20 #define ORION_WR_HIGH_SHIFT 17 #define ORION_WR_HIGH_MASK 0x7 #define ORION_WR_LOW_SHIFT 14 #define ORION_WR_LOW_MASK 0x7 #define ORION_ALE_WR_SHIFT 11 #define ORION_ALE_WR_MASK 0x7 #define ORION_ACC_NEXT_SHIFT 7 #define ORION_ACC_NEXT_MASK 0xF #define ORION_ACC_FIRST_SHIFT 3 #define ORION_ACC_FIRST_MASK 0xF #define ORION_TURN_OFF_SHIFT 0 #define ORION_TURN_OFF_MASK 0x7 struct devbus_read_params { u32 bus_width; u32 badr_skew; u32 turn_off; u32 acc_first; u32 acc_next; u32 rd_setup; u32 rd_hold; }; struct devbus_write_params { u32 sync_enable; u32 wr_high; u32 wr_low; u32 ale_wr; }; struct devbus { struct device *dev; void __iomem *base; unsigned long tick_ps; }; static int get_timing_param_ps(struct devbus *devbus, struct device_node *node, const char *name, u32 *ticks) { u32 time_ps; int err; err = of_property_read_u32(node, name, &time_ps); if (err < 0) { dev_err(devbus->dev, "%s has no '%s' property\n", name, node->full_name); return err; } *ticks = (time_ps + devbus->tick_ps - 1) / devbus->tick_ps; dev_dbg(devbus->dev, "%s: %u ps -> 0x%x\n", name, time_ps, *ticks); return 0; } static int devbus_get_timing_params(struct devbus *devbus, struct device_node *node, struct devbus_read_params *r, struct devbus_write_params *w) { int err; err = of_property_read_u32(node, "devbus,bus-width", &r->bus_width); if (err < 0) { dev_err(devbus->dev, "%s has no 'devbus,bus-width' property\n", node->full_name); return err; } /* * The bus width is encoded into the register as 0 for 8 bits, * and 1 for 16 bits, so we do the necessary conversion here. */ if (r->bus_width == 8) r->bus_width = 0; else if (r->bus_width == 16) r->bus_width = 1; else { dev_err(devbus->dev, "invalid bus width %d\n", r->bus_width); return -EINVAL; } err = get_timing_param_ps(devbus, node, "devbus,badr-skew-ps", &r->badr_skew); if (err < 0) return err; err = get_timing_param_ps(devbus, node, "devbus,turn-off-ps", &r->turn_off); if (err < 0) return err; err = get_timing_param_ps(devbus, node, "devbus,acc-first-ps", &r->acc_first); if (err < 0) return err; err = get_timing_param_ps(devbus, node, "devbus,acc-next-ps", &r->acc_next); if (err < 0) return err; if (of_device_is_compatible(devbus->dev->of_node, "marvell,mvebu-devbus")) { err = get_timing_param_ps(devbus, node, "devbus,rd-setup-ps", &r->rd_setup); if (err < 0) return err; err = get_timing_param_ps(devbus, node, "devbus,rd-hold-ps", &r->rd_hold); if (err < 0) return err; err = of_property_read_u32(node, "devbus,sync-enable", &w->sync_enable); if (err < 0) { dev_err(devbus->dev, "%s has no 'devbus,sync-enable' property\n", node->full_name); return err; } } err = get_timing_param_ps(devbus, node, "devbus,ale-wr-ps", &w->ale_wr); if (err < 0) return err; err = get_timing_param_ps(devbus, node, "devbus,wr-low-ps", &w->wr_low); if (err < 0) return err; err = get_timing_param_ps(devbus, node, "devbus,wr-high-ps", &w->wr_high); if (err < 0) return err; return 0; } static void devbus_orion_set_timing_params(struct devbus *devbus, struct device_node *node, struct devbus_read_params *r, struct devbus_write_params *w) { u32 value; /* * The hardware designers found it would be a good idea to * split most of the values in the register into two fields: * one containing all the low-order bits, and another one * containing just the high-order bit. For all of those * fields, we have to split the value into these two parts. */ value = (r->turn_off & ORION_TURN_OFF_MASK) << ORION_TURN_OFF_SHIFT | (r->acc_first & ORION_ACC_FIRST_MASK) << ORION_ACC_FIRST_SHIFT | (r->acc_next & ORION_ACC_NEXT_MASK) << ORION_ACC_NEXT_SHIFT | (w->ale_wr & ORION_ALE_WR_MASK) << ORION_ALE_WR_SHIFT | (w->wr_low & ORION_WR_LOW_MASK) << ORION_WR_LOW_SHIFT | (w->wr_high & ORION_WR_HIGH_MASK) << ORION_WR_HIGH_SHIFT | r->bus_width << ORION_DEV_WIDTH_SHIFT | ((r->turn_off & ORION_TURN_OFF_EXT_MASK) ? ORION_TURN_OFF_EXT_BIT : 0) | ((r->acc_first & ORION_ACC_FIRST_EXT_MASK) ? ORION_ACC_FIRST_EXT_BIT : 0) | ((r->acc_next & ORION_ACC_NEXT_EXT_MASK) ? ORION_ACC_NEXT_EXT_BIT : 0) | ((w->ale_wr & ORION_ALE_WR_EXT_MASK) ? ORION_ALE_WR_EXT_BIT : 0) | ((w->wr_low & ORION_WR_LOW_EXT_MASK) ? ORION_WR_LOW_EXT_BIT : 0) | ((w->wr_high & ORION_WR_HIGH_EXT_MASK) ? ORION_WR_HIGH_EXT_BIT : 0) | (r->badr_skew << ORION_BADR_SKEW_SHIFT) | ORION_RESERVED; writel(value, devbus->base); } static void devbus_armada_set_timing_params(struct devbus *devbus, struct device_node *node, struct devbus_read_params *r, struct devbus_write_params *w) { u32 value; /* Set read timings */ value = r->bus_width << ARMADA_DEV_WIDTH_SHIFT | r->badr_skew << ARMADA_BADR_SKEW_SHIFT | r->rd_hold << ARMADA_RD_HOLD_SHIFT | r->acc_next << ARMADA_ACC_NEXT_SHIFT | r->rd_setup << ARMADA_RD_SETUP_SHIFT | r->acc_first << ARMADA_ACC_FIRST_SHIFT | r->turn_off; dev_dbg(devbus->dev, "read parameters register 0x%p = 0x%x\n", devbus->base + ARMADA_READ_PARAM_OFFSET, value); writel(value, devbus->base + ARMADA_READ_PARAM_OFFSET); /* Set write timings */ value = w->sync_enable << ARMADA_SYNC_ENABLE_SHIFT | w->wr_low << ARMADA_WR_LOW_SHIFT | w->wr_high << ARMADA_WR_HIGH_SHIFT | w->ale_wr; dev_dbg(devbus->dev, "write parameters register: 0x%p = 0x%x\n", devbus->base + ARMADA_WRITE_PARAM_OFFSET, value); writel(value, devbus->base + ARMADA_WRITE_PARAM_OFFSET); } static int mvebu_devbus_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct device_node *node = pdev->dev.of_node; struct devbus_read_params r; struct devbus_write_params w; struct devbus *devbus; struct resource *res; struct clk *clk; unsigned long rate; int err; devbus = devm_kzalloc(&pdev->dev, sizeof(struct devbus), GFP_KERNEL); if (!devbus) return -ENOMEM; devbus->dev = dev; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); devbus->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(devbus->base)) return PTR_ERR(devbus->base); clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(clk)) return PTR_ERR(clk); clk_prepare_enable(clk); /* * Obtain clock period in picoseconds, * we need this in order to convert timing * parameters from cycles to picoseconds. */ rate = clk_get_rate(clk) / 1000; devbus->tick_ps = 1000000000 / rate; dev_dbg(devbus->dev, "Setting timing parameter, tick is %lu ps\n", devbus->tick_ps); if (!of_property_read_bool(node, "devbus,keep-config")) { /* Read the Device Tree node */ err = devbus_get_timing_params(devbus, node, &r, &w); if (err < 0) return err; /* Set the new timing parameters */ if (of_device_is_compatible(node, "marvell,orion-devbus")) devbus_orion_set_timing_params(devbus, node, &r, &w); else devbus_armada_set_timing_params(devbus, node, &r, &w); } /* * We need to create a child device explicitly from here to * guarantee that the child will be probed after the timing * parameters for the bus are written. */ err = of_platform_populate(node, NULL, NULL, dev); if (err < 0) return err; return 0; } static const struct of_device_id mvebu_devbus_of_match[] = { { .compatible = "marvell,mvebu-devbus" }, { .compatible = "marvell,orion-devbus" }, {}, }; MODULE_DEVICE_TABLE(of, mvebu_devbus_of_match); static struct platform_driver mvebu_devbus_driver = { .probe = mvebu_devbus_probe, .driver = { .name = "mvebu-devbus", .of_match_table = mvebu_devbus_of_match, }, }; static int __init mvebu_devbus_init(void) { return platform_driver_register(&mvebu_devbus_driver); } module_init(mvebu_devbus_init); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Ezequiel Garcia <ezequiel.garcia@free-electrons.com>"); MODULE_DESCRIPTION("Marvell EBU SoC Device Bus controller");