diff options
Diffstat (limited to 'drivers/memory/of_memory.c')
| -rw-r--r-- | drivers/memory/of_memory.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/drivers/memory/of_memory.c b/drivers/memory/of_memory.c new file mode 100644 index 000000000000..60074351f17e --- /dev/null +++ b/drivers/memory/of_memory.c @@ -0,0 +1,153 @@ +/* + * OpenFirmware helpers for memory drivers + * + * Copyright (C) 2012 Texas Instruments, Inc. + * + * 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; either version 2 of the License, or + * (at your option) any later version. + */ + +#include <linux/device.h> +#include <linux/platform_device.h> +#include <linux/list.h> +#include <linux/of.h> +#include <linux/gfp.h> +#include <memory/jedec_ddr.h> +#include <linux/export.h> + +/** + * of_get_min_tck() - extract min timing values for ddr + * @np: pointer to ddr device tree node + * @device: device requesting for min timing values + * + * Populates the lpddr2_min_tck structure by extracting data + * from device tree node. Returns a pointer to the populated + * structure. If any error in populating the structure, returns + * default min timings provided by JEDEC. + */ +const struct lpddr2_min_tck *of_get_min_tck(struct device_node *np, + struct device *dev) +{ + int ret = 0; + struct lpddr2_min_tck *min; + + min = devm_kzalloc(dev, sizeof(*min), GFP_KERNEL); + if (!min) + goto default_min_tck; + + ret |= of_property_read_u32(np, "tRPab-min-tck", &min->tRPab); + ret |= of_property_read_u32(np, "tRCD-min-tck", &min->tRCD); + ret |= of_property_read_u32(np, "tWR-min-tck", &min->tWR); + ret |= of_property_read_u32(np, "tRASmin-min-tck", &min->tRASmin); + ret |= of_property_read_u32(np, "tRRD-min-tck", &min->tRRD); + ret |= of_property_read_u32(np, "tWTR-min-tck", &min->tWTR); + ret |= of_property_read_u32(np, "tXP-min-tck", &min->tXP); + ret |= of_property_read_u32(np, "tRTP-min-tck", &min->tRTP); + ret |= of_property_read_u32(np, "tCKE-min-tck", &min->tCKE); + ret |= of_property_read_u32(np, "tCKESR-min-tck", &min->tCKESR); + ret |= of_property_read_u32(np, "tFAW-min-tck", &min->tFAW); + + if (ret) { + devm_kfree(dev, min); + goto default_min_tck; + } + + return min; + +default_min_tck: + dev_warn(dev, "%s: using default min-tck values\n", __func__); + return &lpddr2_jedec_min_tck; +} +EXPORT_SYMBOL(of_get_min_tck); + +static int of_do_get_timings(struct device_node *np, + struct lpddr2_timings *tim) +{ + int ret; + + ret = of_property_read_u32(np, "max-freq", &tim->max_freq); + ret |= of_property_read_u32(np, "min-freq", &tim->min_freq); + ret |= of_property_read_u32(np, "tRPab", &tim->tRPab); + ret |= of_property_read_u32(np, "tRCD", &tim->tRCD); + ret |= of_property_read_u32(np, "tWR", &tim->tWR); + ret |= of_property_read_u32(np, "tRAS-min", &tim->tRAS_min); + ret |= of_property_read_u32(np, "tRRD", &tim->tRRD); + ret |= of_property_read_u32(np, "tWTR", &tim->tWTR); + ret |= of_property_read_u32(np, "tXP", &tim->tXP); + ret |= of_property_read_u32(np, "tRTP", &tim->tRTP); + ret |= of_property_read_u32(np, "tCKESR", &tim->tCKESR); + ret |= of_property_read_u32(np, "tDQSCK-max", &tim->tDQSCK_max); + ret |= of_property_read_u32(np, "tFAW", &tim->tFAW); + ret |= of_property_read_u32(np, "tZQCS", &tim->tZQCS); + ret |= of_property_read_u32(np, "tZQCL", &tim->tZQCL); + ret |= of_property_read_u32(np, "tZQinit", &tim->tZQinit); + ret |= of_property_read_u32(np, "tRAS-max-ns", &tim->tRAS_max_ns); + ret |= of_property_read_u32(np, "tDQSCK-max-derated", + &tim->tDQSCK_max_derated); + + return ret; +} + +/** + * of_get_ddr_timings() - extracts the ddr timings and updates no of + * frequencies available. + * @np_ddr: Pointer to ddr device tree node + * @dev: Device requesting for ddr timings + * @device_type: Type of ddr(LPDDR2 S2/S4) + * @nr_frequencies: No of frequencies available for ddr + * (updated by this function) + * + * Populates lpddr2_timings structure by extracting data from device + * tree node. Returns pointer to populated structure. If any error + * while populating, returns default timings provided by JEDEC. + */ +const struct lpddr2_timings *of_get_ddr_timings(struct device_node *np_ddr, + struct device *dev, u32 device_type, u32 *nr_frequencies) +{ + struct lpddr2_timings *timings = NULL; + u32 arr_sz = 0, i = 0; + struct device_node *np_tim; + char *tim_compat; + + switch (device_type) { + case DDR_TYPE_LPDDR2_S2: + case DDR_TYPE_LPDDR2_S4: + tim_compat = "jedec,lpddr2-timings"; + break; + default: + dev_warn(dev, "%s: un-supported memory type\n", __func__); + } + + for_each_child_of_node(np_ddr, np_tim) + if (of_device_is_compatible(np_tim, tim_compat)) + arr_sz++; + + if (arr_sz) + timings = devm_kzalloc(dev, sizeof(*timings) * arr_sz, + GFP_KERNEL); + + if (!timings) + goto default_timings; + + for_each_child_of_node(np_ddr, np_tim) { + if (of_device_is_compatible(np_tim, tim_compat)) { + if (of_do_get_timings(np_tim, &timings[i])) { + devm_kfree(dev, timings); + goto default_timings; + } + i++; + } + } + + *nr_frequencies = arr_sz; + + return timings; + +default_timings: + dev_warn(dev, "%s: using default timings\n", __func__); + *nr_frequencies = ARRAY_SIZE(lpddr2_jedec_timings); + return lpddr2_jedec_timings; +} +EXPORT_SYMBOL(of_get_ddr_timings); |