diff options
author | Jon Hunter <jon-hunter@ti.com> | 2013-02-08 16:46:13 -0600 |
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committer | Jon Hunter <jon-hunter@ti.com> | 2013-04-03 20:13:38 -0500 |
commit | cdd6928c589a2dcf084bd62fa5a2b7db1516187b (patch) | |
tree | 3ed13fd349ced1dd80c587c719cb7972236b8b86 /arch/arm/mach-omap2/gpmc.c | |
parent | d36b4cd46d23dd3c283c2e11de540e4cb875255d (diff) | |
download | op-kernel-dev-cdd6928c589a2dcf084bd62fa5a2b7db1516187b.zip op-kernel-dev-cdd6928c589a2dcf084bd62fa5a2b7db1516187b.tar.gz |
ARM: OMAP2+: Add device-tree support for NOR flash
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 <jon-hunter@ti.com>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Diffstat (limited to 'arch/arm/mach-omap2/gpmc.c')
-rw-r--r-- | arch/arm/mach-omap2/gpmc.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c index ab658eb..c7bf6dd 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> @@ -499,6 +500,37 @@ 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 (ret < 0) + return ret; + ret = gpmc_cs_insert_mem(cs, base, size); + if (ret < 0) + 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]; @@ -1386,6 +1418,80 @@ 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) < 0) { + dev_err(&pdev->dev, "%s has malformed 'reg' property\n", + child->full_name); + return -ENODEV; + } + + ret = gpmc_cs_request(cs, resource_size(&res), &base); + if (ret < 0) { + dev_err(&pdev->dev, "cannot request GPMC CS %d\n", cs); + return ret; + } + + /* + * 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 (ret < 0) { + dev_err(&pdev->dev, "cannot remap GPMC CS %d to 0x%x\n", + cs, res.start); + goto err; + } + + gpmc_read_settings_dt(child, &gpmc_s); + + ret = of_property_read_u32(child, "bank-width", &gpmc_s.device_width); + if (ret < 0) + goto err; + + ret = gpmc_cs_program_settings(cs, &gpmc_s); + if (ret < 0) + goto err; + + gpmc_read_timings_dt(child, &gpmc_t); + gpmc_cs_set_timings(cs, &gpmc_t); + + if (of_platform_device_create(child, NULL, &pdev->dev)) + return 0; + + dev_err(&pdev->dev, "failed to create gpmc child %s\n", child->name); + +err: + gpmc_cs_free(cs); + + return ret; +} + static int gpmc_probe_dt(struct platform_device *pdev) { int ret; @@ -1418,6 +1524,15 @@ 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 |