[PATCH 11/14] ARM: OMAP2+: Add device-tree support for NOR flash
From: Jon Hunter <hidden>
Date: 2013-02-26 17:30:38
Also in:
linux-devicetree, linux-omap
Subsystem:
arm port, memory technology devices (mtd), omap general purpose memory controller support, omap power management support, omap2+ support, open firmware and flattened device tree bindings, the rest · Maintainers:
Russell King, Miquel Raynal, Richard Weinberger, Vignesh Raghavendra, Roger Quadros, Tony Lindgren, Kevin Hilman, Aaro Koskinen, Andreas Kemnade, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds
NOR flash is not currently supported when booting with device-tree on OMAP2+ devices. Add support to detect and configure NOR devices when booting with device-tree. Add documentation for the TI GPMC NOR binding. Signed-off-by: Jon Hunter <redacted> --- Documentation/devicetree/bindings/mtd/gpmc-nor.txt | 98 ++++++++++++++++ arch/arm/mach-omap2/gpmc.c | 120 ++++++++++++++++++++ 2 files changed, 218 insertions(+) create mode 100644 Documentation/devicetree/bindings/mtd/gpmc-nor.txt
diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nor.txt b/Documentation/devicetree/bindings/mtd/gpmc-nor.txt
new file mode 100644
index 0000000..8c638fc
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/gpmc-nor.txt@@ -0,0 +1,98 @@ +Device tree bindings for NOR flash connect to TI GPMC + +NOR flash connected to the TI GPMC (found on OMAP boards) are represented as +child nodes of the GPMC controller with a name of "nor". + +All timing relevant properties as well as generic GPMC child properties are +explained in a separate documents. Please refer to +Documentation/devicetree/bindings/bus/ti-gpmc.txt + +Required properties: +- bank-width: Width of NOR flash in bytes. GPMC supports 8-bit and + 16-bit devices and so must be either 1 or 2 bytes. +- compatible: Documentation/devicetree/bindings/mtd/mtd-physmap.txt +- gpmc,cs-on: Chip-select assertion time +- gpmc,cs-rd-off: Chip-select de-assertion time for reads +- gpmc,cs-wr-off: Chip-select de-assertion time for writes +- gpmc,oe-on: Output-enable assertion time +- gpmc,oe-off Output-enable de-assertion time +- gpmc,we-on: Write-enable assertion time +- gpmc,we-off: Write-enable de-assertion time +- gpmc,access: Start cycle to first data capture (read access) +- gpmc,rd-cycle: Total read cycle time +- gpmc,wr-cycle: Total write cycle time +- linux,mtd-name: Documentation/devicetree/bindings/mtd/mtd-physmap.txt +- reg: Chip-select, base address (relative to chip-select) + and size of NOR flash. Note that base address will be + typically 0 as this is the start of the chip-select. + +Optional properties: +- gpmc,XXX Additional GPMC timings and settings parameters. See + Documentation/devicetree/bindings/bus/ti-gpmc.txt + +Optional properties for partiton table parsing: +- #address-cells: should be set to 1 +- #size-cells: should be set to 1 + +Example: + +gpmc: gpmc at 6e000000 { + compatible = "ti,omap3430-gpmc", "simple-bus"; + ti,hwmods = "gpmc"; + reg = <0x6e000000 0x1000>; + interrupts = <20>; + gpmc,num-cs = <8>; + gpmc,num-waitpins = <4>; + #address-cells = <2>; + #size-cells = <1>; + + ranges = <0 0 0x10000000 0x08000000>; + + nor at 0,0 { + compatible = "cfi-flash"; + linux,mtd-name= "intel,pf48f6000m0y1be"; + #address-cells = <1>; + #size-cells = <1>; + reg = <0 0 0x08000000>; + bank-width = <2>; + + gpmc,mux-add-data; + gpmc,cs-on = <0>; + gpmc,cs-rd-off = <186>; + gpmc,cs-wr-off = <186>; + gpmc,adv-on = <12>; + gpmc,adv-rd-off = <48>; + gpmc,adv-wr-off = <48>; + gpmc,oe-on = <54>; + gpmc,oe-off = <168>; + gpmc,we-on = <54>; + gpmc,we-off = <168>; + gpmc,rd-cycle = <186>; + gpmc,wr-cycle = <186>; + gpmc,access = <114>; + gpmc,page-burst-access = <6>; + gpmc,bus-turnaround = <12>; + gpmc,cycle2cycle-delay = <18>; + gpmc,wr-data-mux-bus = <90>; + gpmc,wr-access = <186>; + gpmc,cycle2cycle-samecsen; + gpmc,cycle2cycle-diffcsen; + + partition at 0 { + label = "bootloader-nor"; + reg = <0 0x40000>; + }; + partition at 0x40000 { + label = "params-nor"; + reg = <0x40000 0x40000>; + }; + partition at 0x80000 { + label = "kernel-nor"; + reg = <0x80000 0x200000>; + }; + partition at 0x280000 { + label = "filesystem-nor"; + reg = <0x240000 0x7d80000>; + }; + }; +};
diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index e822d2b..eb167b3 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c@@ -26,6 +26,7 @@ #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/of.h> +#include <linux/of_address.h> #include <linux/of_mtd.h> #include <linux/of_device.h> #include <linux/mtd/nand.h>
@@ -513,6 +514,37 @@ static int gpmc_cs_delete_mem(int cs) return r; } +/** + * gpmc_cs_remap - remaps a chip-select physical base address + * @cs: chip-select to remap + * @base: physical base address to re-map chip-select to + * + * Re-maps a chip-select to a new physical base address specified by + * "base". Returns 0 on success and appropriate negative error code + * on failure. + */ +static int gpmc_cs_remap(int cs, u32 base) +{ + int ret; + u32 old_base, size; + + if (cs > GPMC_CS_NUM) + return -ENODEV; + gpmc_cs_get_memconf(cs, &old_base, &size); + if (base == old_base) + return 0; + gpmc_cs_disable_mem(cs); + ret = gpmc_cs_delete_mem(cs); + if (IS_ERR_VALUE(ret)) + return ret; + ret = gpmc_cs_insert_mem(cs, base, size); + if (IS_ERR_VALUE(ret)) + return ret; + gpmc_cs_enable_mem(cs, base, size); + + return 0; +} + int gpmc_cs_request(int cs, unsigned long size, unsigned long *base) { struct resource *res = &gpmc_cs_mem[cs];
@@ -1172,6 +1204,12 @@ int gpmc_cs_program_settings(int cs, struct gpmc_settings *p) } #ifdef CONFIG_OF +static struct property device_disabled = { + .name = "status", + .length = sizeof("disabled"), + .value = "disabled", +}; + static struct of_device_id gpmc_dt_ids[] = { { .compatible = "ti,omap2420-gpmc" }, { .compatible = "ti,omap2430-gpmc" },
@@ -1391,6 +1429,79 @@ static int gpmc_probe_onenand_child(struct platform_device *pdev, } #endif +/** + * gpmc_probe_nor_child - configures the gpmc for a nor device + * @pdev: pointer to gpmc platform device + * @child: pointer to device-tree node for nor device + * + * Allocates and configures a GPMC chip-select for a NOR flash device. + * Returns 0 on success and appropriate negative error code on failure. + */ +static int gpmc_probe_nor_child(struct platform_device *pdev, + struct device_node *child) +{ + struct gpmc_settings gpmc_s; + struct gpmc_timings gpmc_t; + struct resource res; + unsigned long base; + int ret, cs; + + if (of_property_read_u32(child, "reg", &cs) < 0) { + dev_err(&pdev->dev, "%s has no 'reg' property\n", + child->full_name); + return -ENODEV; + } + + if (of_address_to_resource(child, 0, &res)) { + dev_err(&pdev->dev, "%s has malformed 'reg' property\n", + child->full_name); + return -ENODEV; + } + + ret = gpmc_cs_request(cs, res.end - res.start, &base); + if (IS_ERR_VALUE(ret)) { + dev_err(&pdev->dev, "cannot request GPMC CS %d\n", cs); + goto err1; + } + + /* + * FIXME: gpmc_cs_request() will map the CS to an arbitary + * location in the gpmc address space. When booting with + * device-tree we want the NOR flash to be mapped to the + * location specified in the device-tree blob. So remap the + * CS to this location. Once DT migration is complete should + * just make gpmc_cs_request() map a specific address. + */ + ret = gpmc_cs_remap(cs, res.start); + if (IS_ERR_VALUE(ret)) { + dev_err(&pdev->dev, "cannot remap GPMC CS %d to 0x%x\n", + cs, res.start); + goto err2; + } + + gpmc_read_settings_dt(child, &gpmc_s); + + ret = of_property_read_u32(child, "bank-width", &gpmc_s.device_width); + if (IS_ERR_VALUE(ret)) + goto err2; + + ret = gpmc_cs_program_settings(cs, &gpmc_s); + if (IS_ERR_VALUE(ret)) + goto err2; + + gpmc_read_timings_dt(child, &gpmc_t); + gpmc_cs_set_timings(cs, &gpmc_t); + + return 0; +err2: + gpmc_cs_free(cs); +err1: + /* Prevent registering child device on error */ + of_add_property(child, &device_disabled); + + return ret; +} + static int gpmc_probe_dt(struct platform_device *pdev) { int ret;
@@ -1424,6 +1535,15 @@ static int gpmc_probe_dt(struct platform_device *pdev) return ret; } } + + for_each_node_by_name(child, "nor") { + ret = gpmc_probe_nor_child(pdev, child); + if (ret < 0) { + of_node_put(child); + return ret; + } + } + return 0; } #else
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1.7.10.4