diff options
Diffstat (limited to 'kernel/drivers/memory/mvebu-devbus.c')
| -rw-r--r-- | kernel/drivers/memory/mvebu-devbus.c | 361 |
1 files changed, 361 insertions, 0 deletions
diff --git a/kernel/drivers/memory/mvebu-devbus.c b/kernel/drivers/memory/mvebu-devbus.c new file mode 100644 index 000000000..24852812f --- /dev/null +++ b/kernel/drivers/memory/mvebu-devbus.c @@ -0,0 +1,361 @@ +/* + * 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"); |