diff options
Diffstat (limited to 'drivers/bus')
| -rw-r--r-- | drivers/bus/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/bus/Makefile | 1 | ||||
| -rw-r--r-- | drivers/bus/intel-ixp4xx-eb.c | 429 |
3 files changed, 441 insertions, 0 deletions
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig index e7f7eee6ee9a..a5b96f3aad67 100644 --- a/drivers/bus/Kconfig +++ b/drivers/bus/Kconfig @@ -95,6 +95,17 @@ config IMX_WEIM The WEIM(Wireless External Interface Module) works like a bus. You can attach many different devices on it, such as NOR, onenand. +config INTEL_IXP4XX_EB + bool "Intel IXP4xx expansion bus interface driver" + depends on HAS_IOMEM + depends on ARCH_IXP4XX || COMPILE_TEST + default ARCH_IXP4XX + select MFD_SYSCON + help + Driver for the Intel IXP4xx expansion bus interface. The driver is + needed to set up various chip select configuration parameters before + devices on the expansion bus can be discovered. + config MIPS_CDMM bool "MIPS Common Device Memory Map (CDMM) Driver" depends on CPU_MIPSR2 || CPU_MIPSR5 diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile index 397e35392bff..1c29c5e8ffb8 100644 --- a/drivers/bus/Makefile +++ b/drivers/bus/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_FSL_MC_BUS) += fsl-mc/ obj-$(CONFIG_BT1_APB) += bt1-apb.o obj-$(CONFIG_BT1_AXI) += bt1-axi.o obj-$(CONFIG_IMX_WEIM) += imx-weim.o +obj-$(CONFIG_INTEL_IXP4XX_EB) += intel-ixp4xx-eb.o obj-$(CONFIG_MIPS_CDMM) += mips_cdmm.o obj-$(CONFIG_MVEBU_MBUS) += mvebu-mbus.o diff --git a/drivers/bus/intel-ixp4xx-eb.c b/drivers/bus/intel-ixp4xx-eb.c new file mode 100644 index 000000000000..9acd00da413c --- /dev/null +++ b/drivers/bus/intel-ixp4xx-eb.c @@ -0,0 +1,429 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Intel IXP4xx Expansion Bus Controller + * Copyright (C) 2021 Linaro Ltd. + * + * Author: Linus Walleij <linus.walleij@linaro.org> + */ + +#include <linux/bitfield.h> +#include <linux/bits.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/log2.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#define IXP4XX_EXP_NUM_CS 8 + +#define IXP4XX_EXP_TIMING_CS0 0x00 +#define IXP4XX_EXP_TIMING_CS1 0x04 +#define IXP4XX_EXP_TIMING_CS2 0x08 +#define IXP4XX_EXP_TIMING_CS3 0x0c +#define IXP4XX_EXP_TIMING_CS4 0x10 +#define IXP4XX_EXP_TIMING_CS5 0x14 +#define IXP4XX_EXP_TIMING_CS6 0x18 +#define IXP4XX_EXP_TIMING_CS7 0x1c + +/* Bits inside each CS timing register */ +#define IXP4XX_EXP_TIMING_STRIDE 0x04 +#define IXP4XX_EXP_CS_EN BIT(31) +#define IXP456_EXP_PAR_EN BIT(30) /* Only on IXP45x and IXP46x */ +#define IXP4XX_EXP_T1_MASK GENMASK(28, 27) +#define IXP4XX_EXP_T1_SHIFT 28 +#define IXP4XX_EXP_T2_MASK GENMASK(27, 26) +#define IXP4XX_EXP_T2_SHIFT 26 +#define IXP4XX_EXP_T3_MASK GENMASK(25, 22) +#define IXP4XX_EXP_T3_SHIFT 22 +#define IXP4XX_EXP_T4_MASK GENMASK(21, 20) +#define IXP4XX_EXP_T4_SHIFT 20 +#define IXP4XX_EXP_T5_MASK GENMASK(19, 16) +#define IXP4XX_EXP_T5_SHIFT 16 +#define IXP4XX_EXP_CYC_TYPE_MASK GENMASK(15, 14) +#define IXP4XX_EXP_CYC_TYPE_SHIFT 14 +#define IXP4XX_EXP_SIZE_MASK GENMASK(13, 10) +#define IXP4XX_EXP_SIZE_SHIFT 10 +#define IXP4XX_EXP_CNFG_0 BIT(9) /* Always zero */ +#define IXP43X_EXP_SYNC_INTEL BIT(8) /* Only on IXP43x */ +#define IXP43X_EXP_EXP_CHIP BIT(7) /* Only on IXP43x */ +#define IXP4XX_EXP_BYTE_RD16 BIT(6) +#define IXP4XX_EXP_HRDY_POL BIT(5) /* Only on IXP42x */ +#define IXP4XX_EXP_MUX_EN BIT(4) +#define IXP4XX_EXP_SPLT_EN BIT(3) +#define IXP4XX_EXP_WORD BIT(2) /* Always zero */ +#define IXP4XX_EXP_WR_EN BIT(1) +#define IXP4XX_EXP_BYTE_EN BIT(0) +#define IXP42X_RESERVED (BIT(30)|IXP4XX_EXP_CNFG_0|BIT(8)|BIT(7)|IXP4XX_EXP_WORD) +#define IXP43X_RESERVED (BIT(30)|IXP4XX_EXP_CNFG_0|BIT(5)|IXP4XX_EXP_WORD) + +#define IXP4XX_EXP_CNFG0 0x20 +#define IXP4XX_EXP_CNFG0_MEM_MAP BIT(31) +#define IXP4XX_EXP_CNFG1 0x24 + +#define IXP4XX_EXP_BOOT_BASE 0x00000000 +#define IXP4XX_EXP_NORMAL_BASE 0x50000000 +#define IXP4XX_EXP_STRIDE 0x01000000 + +/* Fuses on the IXP43x */ +#define IXP43X_EXP_UNIT_FUSE_RESET 0x28 +#define IXP43x_EXP_FUSE_SPEED_MASK GENMASK(23, 22) + +/* Number of device tree values in "reg" */ +#define IXP4XX_OF_REG_SIZE 3 + +struct ixp4xx_eb { + struct device *dev; + struct regmap *rmap; + u32 bus_base; + bool is_42x; + bool is_43x; +}; + +struct ixp4xx_exp_tim_prop { + const char *prop; + u32 max; + u32 mask; + u16 shift; +}; + +static const struct ixp4xx_exp_tim_prop ixp4xx_exp_tim_props[] = { + { + .prop = "intel,ixp4xx-eb-t1", + .max = 3, + .mask = IXP4XX_EXP_T1_MASK, + .shift = IXP4XX_EXP_T1_SHIFT, + }, + { + .prop = "intel,ixp4xx-eb-t2", + .max = 3, + .mask = IXP4XX_EXP_T2_MASK, + .shift = IXP4XX_EXP_T2_SHIFT, + }, + { + .prop = "intel,ixp4xx-eb-t3", + .max = 15, + .mask = IXP4XX_EXP_T3_MASK, + .shift = IXP4XX_EXP_T3_SHIFT, + }, + { + .prop = "intel,ixp4xx-eb-t4", + .max = 3, + .mask = IXP4XX_EXP_T4_MASK, + .shift = IXP4XX_EXP_T4_SHIFT, + }, + { + .prop = "intel,ixp4xx-eb-t5", + .max = 15, + .mask = IXP4XX_EXP_T5_MASK, + .shift = IXP4XX_EXP_T5_SHIFT, + }, + { + .prop = "intel,ixp4xx-eb-byte-access-on-halfword", + .max = 1, + .mask = IXP4XX_EXP_BYTE_RD16, + }, + { + .prop = "intel,ixp4xx-eb-hpi-hrdy-pol-high", + .max = 1, + .mask = IXP4XX_EXP_HRDY_POL, + }, + { + .prop = "intel,ixp4xx-eb-mux-address-and-data", + .max = 1, + .mask = IXP4XX_EXP_MUX_EN, + }, + { + .prop = "intel,ixp4xx-eb-ahb-split-transfers", + .max = 1, + .mask = IXP4XX_EXP_SPLT_EN, + }, + { + .prop = "intel,ixp4xx-eb-write-enable", + .max = 1, + .mask = IXP4XX_EXP_WR_EN, + }, + { + .prop = "intel,ixp4xx-eb-byte-access", + .max = 1, + .mask = IXP4XX_EXP_BYTE_EN, + }, +}; + +static void ixp4xx_exp_setup_chipselect(struct ixp4xx_eb *eb, + struct device_node *np, + u32 cs_index, + u32 cs_size) +{ + u32 cs_cfg; + u32 val; + u32 cur_cssize; + u32 cs_order; + int ret; + int i; + + if (eb->is_42x && (cs_index > 7)) { + dev_err(eb->dev, + "invalid chipselect %u, we only support 0-7\n", + cs_index); + return; + } + if (eb->is_43x && (cs_index > 3)) { + dev_err(eb->dev, + "invalid chipselect %u, we only support 0-3\n", + cs_index); + return; + } + + /* Several chip selects can be joined into one device */ + if (cs_size > IXP4XX_EXP_STRIDE) + cur_cssize = IXP4XX_EXP_STRIDE; + else + cur_cssize = cs_size; + + + /* + * The following will read/modify/write the configuration for one + * chipselect, attempting to leave the boot defaults in place unless + * something is explicitly defined. + */ + regmap_read(eb->rmap, IXP4XX_EXP_TIMING_CS0 + + IXP4XX_EXP_TIMING_STRIDE * cs_index, &cs_cfg); + dev_info(eb->dev, "CS%d at %#08x, size %#08x, config before: %#08x\n", + cs_index, eb->bus_base + IXP4XX_EXP_STRIDE * cs_index, + cur_cssize, cs_cfg); + + /* Size set-up first align to 2^9 .. 2^24 */ + cur_cssize = roundup_pow_of_two(cur_cssize); + if (cur_cssize < 512) + cur_cssize = 512; + cs_order = ilog2(cur_cssize); + if (cs_order < 9 || cs_order > 24) { + dev_err(eb->dev, "illegal size order %d\n", cs_order); + return; + } + dev_dbg(eb->dev, "CS%d size order: %d\n", cs_index, cs_order); + cs_cfg &= ~(IXP4XX_EXP_SIZE_MASK); + cs_cfg |= ((cs_order - 9) << IXP4XX_EXP_SIZE_SHIFT); + + for (i = 0; i < ARRAY_SIZE(ixp4xx_exp_tim_props); i++) { + const struct ixp4xx_exp_tim_prop *ip = &ixp4xx_exp_tim_props[i]; + + /* All are regular u32 values */ + ret = of_property_read_u32(np, ip->prop, &val); + if (ret) + continue; + + /* Handle bools (single bits) first */ + if (ip->max == 1) { + if (val) + cs_cfg |= ip->mask; + else + cs_cfg &= ~ip->mask; + dev_info(eb->dev, "CS%d %s %s\n", cs_index, + val ? "enabled" : "disabled", + ip->prop); + continue; + } + + if (val > ip->max) { + dev_err(eb->dev, + "CS%d too high value for %s: %u, capped at %u\n", + cs_index, ip->prop, val, ip->max); + val = ip->max; + } + /* This assumes max value fills all the assigned bits (and it does) */ + cs_cfg &= ~ip->mask; + cs_cfg |= (val << ip->shift); + dev_info(eb->dev, "CS%d set %s to %u\n", cs_index, ip->prop, val); + } + + ret = of_property_read_u32(np, "intel,ixp4xx-eb-cycle-type", &val); + if (!ret) { + if (val > 3) { + dev_err(eb->dev, "illegal cycle type %d\n", val); + return; + } + dev_info(eb->dev, "CS%d set cycle type %d\n", cs_index, val); + cs_cfg &= ~IXP4XX_EXP_CYC_TYPE_MASK; + cs_cfg |= val << IXP4XX_EXP_CYC_TYPE_SHIFT; + } + + if (eb->is_42x) + cs_cfg &= ~IXP42X_RESERVED; + if (eb->is_43x) { + cs_cfg &= ~IXP43X_RESERVED; + /* + * This bit for Intel strata flash is currently unused, but let's + * report it if we find one. + */ + if (cs_cfg & IXP43X_EXP_SYNC_INTEL) + dev_info(eb->dev, "claims to be Intel strata flash\n"); + } + cs_cfg |= IXP4XX_EXP_CS_EN; + + regmap_write(eb->rmap, + IXP4XX_EXP_TIMING_CS0 + IXP4XX_EXP_TIMING_STRIDE * cs_index, + cs_cfg); + dev_info(eb->dev, "CS%d wrote %#08x into CS config\n", cs_index, cs_cfg); + + /* + * If several chip selects are joined together into one big + * device area, we call ourselves recursively for each successive + * chip select. For a 32MB flash chip this results in two calls + * for example. + */ + if (cs_size > IXP4XX_EXP_STRIDE) + ixp4xx_exp_setup_chipselect(eb, np, + cs_index + 1, + cs_size - IXP4XX_EXP_STRIDE); +} + +static void ixp4xx_exp_setup_child(struct ixp4xx_eb *eb, + struct device_node *np) +{ + u32 cs_sizes[IXP4XX_EXP_NUM_CS]; + int num_regs; + u32 csindex; + u32 cssize; + int ret; + int i; + + num_regs = of_property_count_elems_of_size(np, "reg", IXP4XX_OF_REG_SIZE); + if (num_regs <= 0) + return; + dev_dbg(eb->dev, "child %s has %d register sets\n", + of_node_full_name(np), num_regs); + + for (csindex = 0; csindex < IXP4XX_EXP_NUM_CS; csindex++) + cs_sizes[csindex] = 0; + + for (i = 0; i < num_regs; i++) { + u32 rbase, rsize; + + ret = of_property_read_u32_index(np, "reg", + i * IXP4XX_OF_REG_SIZE, &csindex); + if (ret) + break; + ret = of_property_read_u32_index(np, "reg", + i * IXP4XX_OF_REG_SIZE + 1, &rbase); + if (ret) + break; + ret = of_property_read_u32_index(np, "reg", + i * IXP4XX_OF_REG_SIZE + 2, &rsize); + if (ret) + break; + + if (csindex >= IXP4XX_EXP_NUM_CS) { + dev_err(eb->dev, "illegal CS %d\n", csindex); + continue; + } + /* + * The memory window always starts from CS base so we need to add + * the start and size to get to the size from the start of the CS + * base. For example if CS0 is at 0x50000000 and the reg is + * <0 0xe40000 0x40000> the size is e80000. + * + * Roof this if we have several regs setting the same CS. + */ + cssize = rbase + rsize; + dev_dbg(eb->dev, "CS%d size %#08x\n", csindex, cssize); + if (cs_sizes[csindex] < cssize) + cs_sizes[csindex] = cssize; + } + + for (csindex = 0; csindex < IXP4XX_EXP_NUM_CS; csindex++) { + cssize = cs_sizes[csindex]; + if (!cssize) + continue; + /* Just this one, so set it up and return */ + ixp4xx_exp_setup_chipselect(eb, np, csindex, cssize); + } +} + +static int ixp4xx_exp_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct ixp4xx_eb *eb; + struct device_node *child; + bool have_children = false; + u32 val; + int ret; + + eb = devm_kzalloc(dev, sizeof(*eb), GFP_KERNEL); + if (!eb) + return -ENOMEM; + + eb->dev = dev; + eb->is_42x = of_device_is_compatible(np, "intel,ixp42x-expansion-bus-controller"); + eb->is_43x = of_device_is_compatible(np, "intel,ixp43x-expansion-bus-controller"); + + eb->rmap = syscon_node_to_regmap(np); + if (IS_ERR(eb->rmap)) + return dev_err_probe(dev, PTR_ERR(eb->rmap), "no regmap\n"); + + /* We check that the regmap work only on first read */ + ret = regmap_read(eb->rmap, IXP4XX_EXP_CNFG0, &val); + if (ret) + dev_err_probe(dev, ret, "cannot read regmap\n"); + if (val & IXP4XX_EXP_CNFG0_MEM_MAP) + eb->bus_base = IXP4XX_EXP_BOOT_BASE; + else + eb->bus_base = IXP4XX_EXP_NORMAL_BASE; + dev_info(dev, "expansion bus at %08x\n", eb->bus_base); + + if (eb->is_43x) { + /* Check some fuses */ + regmap_read(eb->rmap, IXP43X_EXP_UNIT_FUSE_RESET, &val); + switch (FIELD_GET(IXP43x_EXP_FUSE_SPEED_MASK, val)) { + case 0: + dev_info(dev, "IXP43x at 533 MHz\n"); + break; + case 1: + dev_info(dev, "IXP43x at 400 MHz\n"); + break; + case 2: + dev_info(dev, "IXP43x at 667 MHz\n"); + break; + default: + dev_info(dev, "IXP43x unknown speed\n"); + break; + } + } + + /* Walk over the child nodes and see what chipselects we use */ + for_each_available_child_of_node(np, child) { + ixp4xx_exp_setup_child(eb, child); + /* We have at least one child */ + have_children = true; + } + + if (have_children) + return of_platform_default_populate(np, NULL, dev); + + return 0; +} + +static const struct of_device_id ixp4xx_exp_of_match[] = { + { .compatible = "intel,ixp42x-expansion-bus-controller", }, + { .compatible = "intel,ixp43x-expansion-bus-controller", }, + { .compatible = "intel,ixp45x-expansion-bus-controller", }, + { .compatible = "intel,ixp46x-expansion-bus-controller", }, + { } +}; + +static struct platform_driver ixp4xx_exp_driver = { + .probe = ixp4xx_exp_probe, + .driver = { + .name = "intel-extbus", + .of_match_table = ixp4xx_exp_of_match, + }, +}; +module_platform_driver(ixp4xx_exp_driver); +MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); +MODULE_DESCRIPTION("Intel IXP4xx external bus driver"); +MODULE_LICENSE("GPL"); |