[PATCH v2 4/4] misc: emif: add device tree support to emif driver

Aneesh V
2012-03-15T18:36:03Z

v2:
- Addressed comments from Grant Likely:
Converted occurences of __init to __init_or_module
Removed un-necessary instances of #ifdef CONFIG_OF
- Rebased to v2 of EMIF driver series

v1:
- Rebased to the latest version of EMIF series
- Replace kzalloc()/kfree() with devm_* variants
---
drivers/misc/emif.c | 285 ++++++++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 284 insertions(+), 1 deletions(-)

diff --git a/drivers/misc/emif.c b/drivers/misc/emif.c
index 6d2f776..75f21d2 100644
--- a/drivers/misc/emif.c
+++ b/drivers/misc/emif.c
@@ -18,6 +18,7 @@
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
+#include <linux/of.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/module.h>
@@ -49,6 +50,7 @@
* frequency in effect at the moment)
* @plat_data: Pointer to saved platform data.
* @debugfs_root: dentry to the root folder for EMIF in debugfs
+ * @np_ddr: Pointer to ddr device tree node
*/
struct emif_data {
u8 duplicate;
@@ -63,6 +65,7 @@ struct emif_data {
struct emif_regs *curr_regs;
struct emif_platform_data *plat_data;
struct dentry *debugfs_root;
+ struct device_node *np_ddr;
};

static struct emif_data *emif1;
@@ -1148,6 +1151,270 @@ static int is_custom_config_valid(struct emif_custom_configs *cust_cfgs,
return valid;
}

+#if defined(CONFIG_OF)
+static void __init_or_module of_get_custom_configs(struct device_node *np_emif,
+ struct emif_data *emif)
+{
+ struct emif_custom_configs *cust_cfgs = NULL;
+ int len;
+ const int *lpmode, *poll_intvl;
+
+ lpmode = of_get_property(np_emif, "low-power-mode", &len);
+ poll_intvl = of_get_property(np_emif, "temp-alert-poll-interval", &len);
+
+ if (lpmode || poll_intvl)
+ cust_cfgs = devm_kzalloc(emif->dev, sizeof(*cust_cfgs),
+ GFP_KERNEL);
+
+ if (!cust_cfgs)
+ return;
+
+ if (lpmode) {
+ cust_cfgs->mask |= EMIF_CUSTOM_CONFIG_LPMODE;
+ cust_cfgs->lpmode = *lpmode;
+ of_property_read_u32(np_emif,
+ "low-power-mode-timeout-performance",
+ &cust_cfgs->lpmode_timeout_performance);
+ of_property_read_u32(np_emif,
+ "low-power-mode-timeout-power",
+ &cust_cfgs->lpmode_timeout_power);
+ of_property_read_u32(np_emif,
+ "low-power-mode-freq-threshold",
+ &cust_cfgs->lpmode_freq_threshold);
+ }
+
+ if (poll_intvl) {
+ cust_cfgs->mask |=
+ EMIF_CUSTOM_CONFIG_TEMP_ALERT_POLL_INTERVAL;
+ cust_cfgs->temp_alert_poll_interval_ms = *poll_intvl;
+ }
+
+ if (!is_custom_config_valid(cust_cfgs, emif->dev)) {
+ devm_kfree(emif->dev, cust_cfgs);
+ return;
+ }
+
+ emif->plat_data->custom_configs = cust_cfgs;
+}
+
+static void __init_or_module of_get_min_tck(struct device_node *np,
+ struct emif_data *emif)
+{
+ int ret = 0;
+ struct lpddr2_min_tck *min;
+
+ min = devm_kzalloc(emif->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(emif->dev, min);
+ goto default_min_tck;
+ }
+
+ emif->plat_data->min_tck = min;
+ return;
+
+default_min_tck:
+ dev_warn(emif->dev, "%s: using default min-tck values\n", __func__);
+ emif->plat_data->min_tck = &lpddr2_jedec_min_tck;
+}
+
+static int __init_or_module 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;
+}
+
+static void __init_or_module of_get_ddr_timings(struct device_node *np_ddr,
+ struct emif_data *emif)
+{
+ struct lpddr2_timings *timings = NULL;
+ u32 arr_sz = 0, i = 0;
+ struct device_node *np_tim;
+ char *tim_compat;
+
+ switch (emif->plat_data->device_info->type) {
+ case DDR_TYPE_LPDDR2_S2:
+ case DDR_TYPE_LPDDR2_S4:
+ tim_compat = "jedec,lpddr2-timings";
+ break;
+ default:
+ dev_warn(emif->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(emif->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(emif->dev, timings);
+ goto default_timings;
+ }
+ i++;
+ }
+ }
+
+ emif->plat_data->timings = timings;
+ emif->plat_data->timings_arr_size = arr_sz;
+
+ return;
+
+default_timings:
+ get_default_timings(emif);
+
+ return;
+}
+
+static void __init_or_module of_get_ddr_info(struct device_node *np_emif,
+ struct device_node *np_ddr,
+ struct ddr_device_info *dev_info)
+{
+ u32 density = 0, io_width = 0;
+ int len;
+
+ if (of_find_property(np_emif, "cs1-used", &len))
+ dev_info->cs1_used = true;
+
+ if (of_find_property(np_emif, "cal-resistor-per-cs", &len))
+ dev_info->cal_resistors_per_cs = true;
+
+ if (of_device_is_compatible(np_ddr , "jedec,lpddr2-s4"))
+ dev_info->type = DDR_TYPE_LPDDR2_S4;
+ else if (of_device_is_compatible(np_ddr , "jedec,lpddr2-s2"))
+ dev_info->type = DDR_TYPE_LPDDR2_S2;
+
+ of_property_read_u32(np_ddr, "density", &density);
+ of_property_read_u32(np_ddr, "io-width", &io_width);
+
+ /* Convert from density in Mb to the density encoding in jedc_ddr.h */
+ if (density & (density - 1))
+ dev_info->density = 0;
+ else
+ dev_info->density = __fls(density) - 5;
+
+ /* Convert from io_width in bits to io_width encoding in jedc_ddr.h */
+ if (io_width & (io_width - 1))
+ dev_info->io_width = 0;
+ else
+ dev_info->io_width = __fls(io_width) - 1;
+}
+
+static struct emif_data * __init_or_module of_get_device_details(
+ struct device_node *np_emif, struct device *dev)
+{
+ struct emif_data *emif = NULL;
+ struct ddr_device_info *dev_info = NULL;
+ struct emif_platform_data *pd = NULL;
+ struct device_node *np_ddr;
+ int len;
+
+ np_ddr = of_parse_phandle(np_emif, "device-handle", 0);
+ if (!np_ddr)
+ goto error;
+ emif = devm_kzalloc(dev, sizeof(struct emif_data), GFP_KERNEL);
+ pd = devm_kzalloc(dev, sizeof(*pd), GFP_KERNEL);
+ dev_info = devm_kzalloc(dev, sizeof(*dev_info), GFP_KERNEL);
+
+ if (!emif || !pd || !dev_info) {
+ dev_err(dev, "%s: of_get_device_details() failure!!\n",
+ __func__);
+ goto error;
+ }
+
+ emif->plat_data = pd;
+ pd->device_info = dev_info;
+ emif->dev = dev;
+ emif->np_ddr = np_ddr;
+ emif->temperature_level = SDRAM_TEMP_NOMINAL;
+
+ if (of_device_is_compatible(np_emif, "ti,emif-4d"))
+ emif->plat_data->ip_rev = EMIF_4D;
+ else if (of_device_is_compatible(np_emif, "ti,emif-4d5"))
+ emif->plat_data->ip_rev = EMIF_4D5;
+
+ of_property_read_u32(np_emif, "phy-type", &pd->phy_type);
+
+ if (of_find_property(np_emif, "hw-caps-ll-interface", &len))
+ pd->hw_caps |= EMIF_HW_CAPS_LL_INTERFACE;
+
+ of_get_ddr_info(np_emif, np_ddr, dev_info);
+ if (!is_dev_data_valid(pd->device_info->type, pd->device_info->density,
+ pd->device_info->io_width, pd->phy_type, pd->ip_rev,
+ emif->dev)) {
+ dev_err(dev, "%s: invalid device data!!\n", __func__);
+ goto error;
+ }
+ /*
+ * For EMIF instances other than EMIF1 see if the devices connected
+ * are exactly same as on EMIF1(which is typically the case). If so,
+ * mark it as a duplicate of EMIF1. This will save some memory and
+ * computation.
+ */
+ if (emif1 && emif1->np_ddr == np_ddr) {
+ emif->duplicate = true;
+ goto out;
+ } else if (emif1) {
+ dev_warn(emif->dev, "%s: Non-symmetric DDR geometry\n",
+ __func__);
+ }
+
+
+ of_get_custom_configs(np_emif, emif);
+ of_get_ddr_timings(np_ddr, emif);
+ of_get_min_tck(np_ddr, emif);
+ goto out;
+
+error:
+ return NULL;
+out:
+ return emif;
+}
+#endif
+
static struct emif_data *__init_or_module get_device_details(
struct platform_device *pdev)
{
@@ -1267,7 +1534,13 @@ static int __init_or_module emif_probe(struct platform_device *pdev)
struct resource *res;
int irq;

- emif = get_device_details(pdev);
+#if defined(CONFIG_OF)
+ if (pdev->dev.of_node)
+ emif = of_get_device_details(pdev->dev.of_node, &pdev->dev);
+ else
+#endif
+ emif = get_device_details(pdev);
+
if (!emif) {
pr_err("%s: error getting device data\n", __func__);
goto error;
@@ -1644,11 +1917,21 @@ static void __attribute__((unused)) freq_post_notify_handling(void)
spin_unlock_irqrestore(&emif_lock, irq_state);
}

+#if defined(CONFIG_OF)
+static const struct of_device_id emif_of_match[] = {
+ { .compatible = "ti,emif-4d" },
+ { .compatible = "ti,emif-4d5" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, emif_of_match);
+#endif
+
static struct platform_driver emif_driver = {
.remove = __exit_p(emif_remove),
.shutdown = emif_shutdown,
.driver = {
.name = "emif",
+ .of_match_table = of_match_ptr(emif_of_match),
},
};

--
1.7.1