diff options
| -rw-r--r-- | Documentation/devicetree/bindings/spi/nuvoton,wpcm450-fiu.yaml | 66 | ||||
| -rw-r--r-- | drivers/spi/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/spi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/spi/spi-wpcm-fiu.c | 508 |
4 files changed, 586 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/spi/nuvoton,wpcm450-fiu.yaml b/Documentation/devicetree/bindings/spi/nuvoton,wpcm450-fiu.yaml new file mode 100644 index 000000000000..ef94803e75d9 --- /dev/null +++ b/Documentation/devicetree/bindings/spi/nuvoton,wpcm450-fiu.yaml @@ -0,0 +1,66 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/spi/nuvoton,wpcm450-fiu.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Nuvoton WPCM450 Flash Interface Unit (FIU) + +maintainers: + - Jonathan Neuschäfer <j.neuschaefer@gmx.net> + +allOf: + - $ref: /schemas/spi/spi-controller.yaml# + +properties: + compatible: + const: nuvoton,wpcm450-fiu + + reg: + items: + - description: FIU registers + - description: Memory-mapped flash contents + + reg-names: + items: + - const: control + - const: memory + + interrupts: + maxItems: 1 + + clocks: + maxItems: 1 + + nuvoton,shm: + $ref: /schemas/types.yaml#/definitions/phandle + description: a phandle to the SHM block (see ../arm/nuvoton,shm.yaml) + +required: + - compatible + - reg + - clocks + +unevaluatedProperties: false + +examples: + - | + #include <dt-bindings/clock/nuvoton,wpcm450-clk.h> + spi@c8000000 { + compatible = "nuvoton,wpcm450-fiu"; + reg = <0xc8000000 0x1000>, <0xc0000000 0x4000000>; + #address-cells = <1>; + #size-cells = <0>; + reg-names = "control", "memory"; + clocks = <&clk WPCM450_CLK_FIU>; + nuvoton,shm = <&shm>; + + flash@0 { + compatible = "jedec,spi-nor"; + }; + }; + + shm: syscon@c8001000 { + compatible = "nuvoton,wpcm450-shm", "syscon"; + reg = <0xc8001000 0x1000>; + }; diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 160d8d00c389..3b1c0878bb85 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -635,6 +635,17 @@ config SPI_MTK_SNFI is implemented as a SPI-MEM controller with pipelined ECC capcability. +config SPI_WPCM_FIU + tristate "Nuvoton WPCM450 Flash Interface Unit" + depends on ARCH_NPCM || COMPILE_TEST + select REGMAP + help + This enables support got the Flash Interface Unit SPI controller + present in the Nuvoton WPCM450 SoC. + + This driver does not support generic SPI. The implementation only + supports the spi-mem interface. + config SPI_NPCM_FIU tristate "Nuvoton NPCM FLASH Interface Unit" depends on ARCH_NPCM || COMPILE_TEST diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 971bd62e4481..be9ba40ef8d0 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -83,6 +83,7 @@ obj-$(CONFIG_SPI_MTK_NOR) += spi-mtk-nor.o obj-$(CONFIG_SPI_MTK_SNFI) += spi-mtk-snfi.o obj-$(CONFIG_SPI_MXIC) += spi-mxic.o obj-$(CONFIG_SPI_MXS) += spi-mxs.o +obj-$(CONFIG_SPI_WPCM_FIU) += spi-wpcm-fiu.o obj-$(CONFIG_SPI_NPCM_FIU) += spi-npcm-fiu.o obj-$(CONFIG_SPI_NPCM_PSPI) += spi-npcm-pspi.o obj-$(CONFIG_SPI_NXP_FLEXSPI) += spi-nxp-fspi.o diff --git a/drivers/spi/spi-wpcm-fiu.c b/drivers/spi/spi-wpcm-fiu.c new file mode 100644 index 000000000000..ab33710d50ac --- /dev/null +++ b/drivers/spi/spi-wpcm-fiu.c @@ -0,0 +1,508 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2022 Jonathan Neuschäfer + +#include <linux/clk.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/spi/spi-mem.h> + +#define FIU_CFG 0x00 +#define FIU_BURST_BFG 0x01 +#define FIU_RESP_CFG 0x02 +#define FIU_CFBB_PROT 0x03 +#define FIU_FWIN1_LOW 0x04 +#define FIU_FWIN1_HIGH 0x06 +#define FIU_FWIN2_LOW 0x08 +#define FIU_FWIN2_HIGH 0x0a +#define FIU_FWIN3_LOW 0x0c +#define FIU_FWIN3_HIGH 0x0e +#define FIU_PROT_LOCK 0x10 +#define FIU_PROT_CLEAR 0x11 +#define FIU_SPI_FL_CFG 0x14 +#define FIU_UMA_CODE 0x16 +#define FIU_UMA_AB0 0x17 +#define FIU_UMA_AB1 0x18 +#define FIU_UMA_AB2 0x19 +#define FIU_UMA_DB0 0x1a +#define FIU_UMA_DB1 0x1b +#define FIU_UMA_DB2 0x1c +#define FIU_UMA_DB3 0x1d +#define FIU_UMA_CTS 0x1e +#define FIU_UMA_ECTS 0x1f + +#define FIU_BURST_CFG_R16 3 + +#define FIU_UMA_CTS_D_SIZE(x) (x) +#define FIU_UMA_CTS_A_SIZE BIT(3) +#define FIU_UMA_CTS_WR BIT(4) +#define FIU_UMA_CTS_CS(x) ((x) << 5) +#define FIU_UMA_CTS_EXEC_DONE BIT(7) + +#define SHM_FLASH_SIZE 0x02 +#define SHM_FLASH_SIZE_STALL_HOST BIT(6) + +/* + * I observed a typical wait time of 16 iterations for a UMA transfer to + * finish, so this should be a safe limit. + */ +#define UMA_WAIT_ITERATIONS 100 + +/* The memory-mapped view of flash is 16 MiB long */ +#define MAX_MEMORY_SIZE_PER_CS (16 << 20) +#define MAX_MEMORY_SIZE_TOTAL (4 * MAX_MEMORY_SIZE_PER_CS) + +struct wpcm_fiu_spi { + struct device *dev; + struct clk *clk; + void __iomem *regs; + void __iomem *memory; + size_t memory_size; + struct regmap *shm_regmap; +}; + +static void wpcm_fiu_set_opcode(struct wpcm_fiu_spi *fiu, u8 opcode) +{ + writeb(opcode, fiu->regs + FIU_UMA_CODE); +} + +static void wpcm_fiu_set_addr(struct wpcm_fiu_spi *fiu, u32 addr) +{ + writeb((addr >> 0) & 0xff, fiu->regs + FIU_UMA_AB0); + writeb((addr >> 8) & 0xff, fiu->regs + FIU_UMA_AB1); + writeb((addr >> 16) & 0xff, fiu->regs + FIU_UMA_AB2); +} + +static void wpcm_fiu_set_data(struct wpcm_fiu_spi *fiu, const u8 *data, unsigned int nbytes) +{ + int i; + + for (i = 0; i < nbytes; i++) + writeb(data[i], fiu->regs + FIU_UMA_DB0 + i); +} + +static void wpcm_fiu_get_data(struct wpcm_fiu_spi *fiu, u8 *data, unsigned int nbytes) +{ + int i; + + for (i = 0; i < nbytes; i++) + data[i] = readb(fiu->regs + FIU_UMA_DB0 + i); +} + +/* + * Perform a UMA (User Mode Access) operation, i.e. a software-controlled SPI transfer. + */ +static int wpcm_fiu_do_uma(struct wpcm_fiu_spi *fiu, unsigned int cs, + bool use_addr, bool write, int data_bytes) +{ + int i = 0; + u8 cts = FIU_UMA_CTS_EXEC_DONE | FIU_UMA_CTS_CS(cs); + + if (use_addr) + cts |= FIU_UMA_CTS_A_SIZE; + if (write) + cts |= FIU_UMA_CTS_WR; + cts |= FIU_UMA_CTS_D_SIZE(data_bytes); + + writeb(cts, fiu->regs + FIU_UMA_CTS); + + for (i = 0; i < UMA_WAIT_ITERATIONS; i++) + if (!(readb(fiu->regs + FIU_UMA_CTS) & FIU_UMA_CTS_EXEC_DONE)) + return 0; + + dev_info(fiu->dev, "UMA transfer has not finished in %d iterations\n", UMA_WAIT_ITERATIONS); + return -EIO; +} + +static void wpcm_fiu_ects_assert(struct wpcm_fiu_spi *fiu, unsigned int cs) +{ + u8 ects = readb(fiu->regs + FIU_UMA_ECTS); + + ects &= ~BIT(cs); + writeb(ects, fiu->regs + FIU_UMA_ECTS); +} + +static void wpcm_fiu_ects_deassert(struct wpcm_fiu_spi *fiu, unsigned int cs) +{ + u8 ects = readb(fiu->regs + FIU_UMA_ECTS); + + ects |= BIT(cs); + writeb(ects, fiu->regs + FIU_UMA_ECTS); +} + +struct wpcm_fiu_op_shape { + bool (*match)(const struct spi_mem_op *op); + int (*exec)(struct spi_mem *mem, const struct spi_mem_op *op); +}; + +static bool wpcm_fiu_normal_match(const struct spi_mem_op *op) +{ + // Opcode 0x0b (FAST READ) is treated differently in hardware + if (op->cmd.opcode == 0x0b) + return false; + + return (op->addr.nbytes == 0 || op->addr.nbytes == 3) && + op->dummy.nbytes == 0 && op->data.nbytes <= 4; +} + +static int wpcm_fiu_normal_exec(struct spi_mem *mem, const struct spi_mem_op *op) +{ + struct wpcm_fiu_spi *fiu = spi_controller_get_devdata(mem->spi->controller); + int ret; + + wpcm_fiu_set_opcode(fiu, op->cmd.opcode); + wpcm_fiu_set_addr(fiu, op->addr.val); + if (op->data.dir == SPI_MEM_DATA_OUT) + wpcm_fiu_set_data(fiu, op->data.buf.out, op->data.nbytes); + + ret = wpcm_fiu_do_uma(fiu, mem->spi->chip_select, op->addr.nbytes == 3, + op->data.dir == SPI_MEM_DATA_OUT, op->data.nbytes); + + if (op->data.dir == SPI_MEM_DATA_IN) + wpcm_fiu_get_data(fiu, op->data.buf.in, op->data.nbytes); + + return ret; +} + +static bool wpcm_fiu_fast_read_match(const struct spi_mem_op *op) +{ + return op->cmd.opcode == 0x0b && op->addr.nbytes == 3 && + op->dummy.nbytes == 1 && + op->data.nbytes >= 1 && op->data.nbytes <= 4 && + op->data.dir == SPI_MEM_DATA_IN; +} + +static int wpcm_fiu_fast_read_exec(struct spi_mem *mem, const struct spi_mem_op *op) +{ + return -EINVAL; +} + +/* + * 4-byte addressing. + * + * Flash view: [ C A A A A D D D D] + * bytes: 13 aa bb cc dd -> 5a a5 f0 0f + * FIU's view: [ C A A A][ C D D D D] + * FIU mode: [ read/write][ read ] + */ +static bool wpcm_fiu_4ba_match(const struct spi_mem_op *op) +{ + return op->addr.nbytes == 4 && op->dummy.nbytes == 0 && op->data.nbytes <= 4; +} + +static int wpcm_fiu_4ba_exec(struct spi_mem *mem, const struct spi_mem_op *op) +{ + struct wpcm_fiu_spi *fiu = spi_controller_get_devdata(mem->spi->controller); + int cs = mem->spi->chip_select; + + wpcm_fiu_ects_assert(fiu, cs); + + wpcm_fiu_set_opcode(fiu, op->cmd.opcode); + wpcm_fiu_set_addr(fiu, op->addr.val >> 8); + wpcm_fiu_do_uma(fiu, cs, true, false, 0); + + wpcm_fiu_set_opcode(fiu, op->addr.val & 0xff); + wpcm_fiu_set_addr(fiu, 0); + if (op->data.dir == SPI_MEM_DATA_OUT) + wpcm_fiu_set_data(fiu, op->data.buf.out, op->data.nbytes); + wpcm_fiu_do_uma(fiu, cs, false, op->data.dir == SPI_MEM_DATA_OUT, op->data.nbytes); + + wpcm_fiu_ects_deassert(fiu, cs); + + if (op->data.dir == SPI_MEM_DATA_IN) + wpcm_fiu_get_data(fiu, op->data.buf.in, op->data.nbytes); + + return 0; +} + +/* + * RDID (Read Identification) needs special handling because Linux expects to + * be able to read 6 ID bytes and FIU can only read up to 4 at once. + * + * We're lucky in this case, because executing the RDID instruction twice will + * result in the same result. + * + * What we do is as follows (C: write command/opcode byte, D: read data byte, + * A: write address byte): + * + * 1. C D D D + * 2. C A A A D D D + */ +static bool wpcm_fiu_rdid_match(const struct spi_mem_op *op) +{ + return op->cmd.opcode == 0x9f && op->addr.nbytes == 0 && + op->dummy.nbytes == 0 && op->data.nbytes == 6 && + op->data.dir == SPI_MEM_DATA_IN; +} + +static int wpcm_fiu_rdid_exec(struct spi_mem *mem, const struct spi_mem_op *op) +{ + struct wpcm_fiu_spi *fiu = spi_controller_get_devdata(mem->spi->controller); + int cs = mem->spi->chip_select; + + /* First transfer */ + wpcm_fiu_set_opcode(fiu, op->cmd.opcode); + wpcm_fiu_set_addr(fiu, 0); + wpcm_fiu_do_uma(fiu, cs, false, false, 3); + wpcm_fiu_get_data(fiu, op->data.buf.in, 3); + + /* Second transfer */ + wpcm_fiu_set_opcode(fiu, op->cmd.opcode); + wpcm_fiu_set_addr(fiu, 0); + wpcm_fiu_do_uma(fiu, cs, true, false, 3); + wpcm_fiu_get_data(fiu, op->data.buf.in + 3, 3); + + return 0; +} + +/* + * With some dummy bytes. + * + * C A A A X* X D D D D + * [C A A A D*][C D D D D] + */ +static bool wpcm_fiu_dummy_match(const struct spi_mem_op *op) +{ + // Opcode 0x0b (FAST READ) is treated differently in hardware + if (op->cmd.opcode == 0x0b) + return false; + + return (op->addr.nbytes == 0 || op->addr.nbytes == 3) && + op->dummy.nbytes >= 1 && op->dummy.nbytes <= 5 && + op->data.nbytes <= 4; +} + +static int wpcm_fiu_dummy_exec(struct spi_mem *mem, const struct spi_mem_op *op) +{ + struct wpcm_fiu_spi *fiu = spi_controller_get_devdata(mem->spi->controller); + int cs = mem->spi->chip_select; + + wpcm_fiu_ects_assert(fiu, cs); + + /* First transfer */ + wpcm_fiu_set_opcode(fiu, op->cmd.opcode); + wpcm_fiu_set_addr(fiu, op->addr.val); + wpcm_fiu_do_uma(fiu, cs, op->addr.nbytes != 0, true, op->dummy.nbytes - 1); + + /* Second transfer */ + wpcm_fiu_set_opcode(fiu, 0); + wpcm_fiu_set_addr(fiu, 0); + wpcm_fiu_do_uma(fiu, cs, false, false, op->data.nbytes); + wpcm_fiu_get_data(fiu, op->data.buf.in, op->data.nbytes); + + wpcm_fiu_ects_deassert(fiu, cs); + + return 0; +} + +static const struct wpcm_fiu_op_shape wpcm_fiu_op_shapes[] = { + { .match = wpcm_fiu_normal_match, .exec = wpcm_fiu_normal_exec }, + { .match = wpcm_fiu_fast_read_match, .exec = wpcm_fiu_fast_read_exec }, + { .match = wpcm_fiu_4ba_match, .exec = wpcm_fiu_4ba_exec }, + { .match = wpcm_fiu_rdid_match, .exec = wpcm_fiu_rdid_exec }, + { .match = wpcm_fiu_dummy_match, .exec = wpcm_fiu_dummy_exec }, +}; + +static const struct wpcm_fiu_op_shape *wpcm_fiu_find_op_shape(const struct spi_mem_op *op) +{ + size_t i; + + for (i = 0; i < ARRAY_SIZE(wpcm_fiu_op_shapes); i++) { + const struct wpcm_fiu_op_shape *shape = &wpcm_fiu_op_shapes[i]; + + if (shape->match(op)) + return shape; + } + + return NULL; +} + +static bool wpcm_fiu_supports_op(struct spi_mem *mem, const struct spi_mem_op *op) +{ + if (!spi_mem_default_supports_op(mem, op)) + return false; + + if (op->cmd.dtr || op->addr.dtr || op->dummy.dtr || op->data.dtr) + return false; + + if (op->cmd.buswidth > 1 || op->addr.buswidth > 1 || + op->dummy.buswidth > 1 || op->data.buswidth > 1) + return false; + + return wpcm_fiu_find_op_shape(op) != NULL; +} + +/* + * In order to ensure the integrity of SPI transfers performed via UMA, + * temporarily disable (stall) memory accesses coming from the host CPU. + */ +static void wpcm_fiu_stall_host(struct wpcm_fiu_spi *fiu, bool stall) +{ + if (fiu->shm_regmap) { + int res = regmap_update_bits(fiu->shm_regmap, SHM_FLASH_SIZE, + SHM_FLASH_SIZE_STALL_HOST, + stall ? SHM_FLASH_SIZE_STALL_HOST : 0); + if (res) + dev_warn(fiu->dev, "Failed to (un)stall host memory accesses: %d\n", res); + } +} + +static int wpcm_fiu_exec_op(struct spi_mem *mem, const struct spi_mem_op *op) +{ + struct wpcm_fiu_spi *fiu = spi_controller_get_devdata(mem->spi->controller); + const struct wpcm_fiu_op_shape *shape = wpcm_fiu_find_op_shape(op); + + wpcm_fiu_stall_host(fiu, true); + + if (shape) + return shape->exec(mem, op); + + wpcm_fiu_stall_host(fiu, false); + + return -ENOTSUPP; +} + +static int wpcm_fiu_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op) +{ + if (op->data.nbytes > 4) + op->data.nbytes = 4; + + return 0; +} + +static int wpcm_fiu_dirmap_create(struct spi_mem_dirmap_desc *desc) +{ + struct wpcm_fiu_spi *fiu = spi_controller_get_devdata(desc->mem->spi->controller); + int cs = desc->mem->spi->chip_select; + + if (desc->info.op_tmpl.data.dir != SPI_MEM_DATA_IN) + return -ENOTSUPP; + + /* + * Unfortunately, FIU only supports a 16 MiB direct mapping window (per + * attached flash chip), but the SPI MEM core doesn't support partial + * direct mappings. This means that we can't support direct mapping on + * flashes that are bigger than 16 MiB. + */ + if (desc->info.offset + desc->info.length > MAX_MEMORY_SIZE_PER_CS) + return -ENOTSUPP; + + /* Don't read past the memory window */ + if (cs * MAX_MEMORY_SIZE_PER_CS + desc->info.offset + desc->info.length > fiu->memory_size) + return -ENOTSUPP; + + return 0; +} + +static ssize_t wpcm_fiu_direct_read(struct spi_mem_dirmap_desc *desc, u64 offs, size_t len, void *buf) +{ + struct wpcm_fiu_spi *fiu = spi_controller_get_devdata(desc->mem->spi->controller); + int cs = desc->mem->spi->chip_select; + + if (offs >= MAX_MEMORY_SIZE_PER_CS) + return -ENOTSUPP; + + offs += cs * MAX_MEMORY_SIZE_PER_CS; + + if (!fiu->memory || offs >= fiu->memory_size) + return -ENOTSUPP; + + len = min_t(size_t, len, fiu->memory_size - offs); + memcpy_fromio(buf, fiu->memory + offs, len); + + return len; +} + +static const struct spi_controller_mem_ops wpcm_fiu_mem_ops = { + .adjust_op_size = wpcm_fiu_adjust_op_size, + .supports_op = wpcm_fiu_supports_op, + .exec_op = wpcm_fiu_exec_op, + .dirmap_create = wpcm_fiu_dirmap_create, + .dirmap_read = wpcm_fiu_direct_read, +}; + +static void wpcm_fiu_hw_init(struct wpcm_fiu_spi *fiu) +{ + /* Configure memory-mapped flash access */ + writeb(FIU_BURST_CFG_R16, fiu->regs + FIU_BURST_BFG); + writeb(MAX_MEMORY_SIZE_TOTAL / (512 << 10), fiu->regs + FIU_CFG); + writeb(MAX_MEMORY_SIZE_PER_CS / (512 << 10) | BIT(6), fiu->regs + FIU_SPI_FL_CFG); + + /* Deassert all manually asserted chip selects */ + writeb(0x0f, fiu->regs + FIU_UMA_ECTS); +} + +static int wpcm_fiu_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct spi_controller *ctrl; + struct wpcm_fiu_spi *fiu; + struct resource *res; + + ctrl = devm_spi_alloc_master(dev, sizeof(*fiu)); + if (!ctrl) + return -ENOMEM; + + fiu = spi_controller_get_devdata(ctrl); + fiu->dev = dev; + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "control"); + fiu->regs = devm_ioremap_resource(dev, res); + if (IS_ERR(fiu->regs)) { + dev_err(dev, "Failed to map registers\n"); + return PTR_ERR(fiu->regs); + } + + fiu->clk = devm_clk_get_enabled(dev, NULL); + if (IS_ERR(fiu->clk)) + return PTR_ERR(fiu->clk); + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "memory"); + fiu->memory = devm_ioremap_resource(dev, res); + fiu->memory_size = min_t(size_t, resource_size(res), MAX_MEMORY_SIZE_TOTAL); + if (IS_ERR(fiu->memory)) { + dev_err(dev, "Failed to map flash memory window\n"); + return PTR_ERR(fiu->memory); + } + + fiu->shm_regmap = syscon_regmap_lookup_by_phandle_optional(dev->of_node, "nuvoton,shm"); + + wpcm_fiu_hw_init(fiu); + + ctrl->bus_num = -1; + ctrl->mem_ops = &wpcm_fiu_mem_ops; + ctrl->num_chipselect = 4; + ctrl->dev.of_node = dev->of_node; + + /* + * The FIU doesn't include a clock divider, the clock is entirely + * determined by the AHB3 bus clock. + */ + ctrl->min_speed_hz = clk_get_rate(fiu->clk); + ctrl->max_speed_hz = clk_get_rate(fiu->clk); + + return devm_spi_register_controller(dev, ctrl); +} + +static const struct of_device_id wpcm_fiu_dt_ids[] = { + { .compatible = "nuvoton,wpcm450-fiu", }, + { } +}; +MODULE_DEVICE_TABLE(of, wpcm_fiu_dt_ids); + +static struct platform_driver wpcm_fiu_driver = { + .driver = { + .name = "wpcm450-fiu", + .bus = &platform_bus_type, + .of_match_table = wpcm_fiu_dt_ids, + }, + .probe = wpcm_fiu_probe, +}; +module_platform_driver(wpcm_fiu_driver); + +MODULE_DESCRIPTION("Nuvoton WPCM450 FIU SPI controller driver"); +MODULE_AUTHOR("Jonathan Neuschäfer <j.neuschaefer@gmx.net>"); +MODULE_LICENSE("GPL"); |