ARM: OMAP2+: onenand: refactor for clarity

Refactor set_async_mode & set_sync_mode functions to
separate out timing calculation & actual configuration
(GPMC & OneNAND side).

Thanks to Jon for his suggestions.

Signed-off-by: Afzal Mohammed <afzal@ti.com>
Reviewed-by: Jon Hunter <jon-hunter@ti.com>

1 files changed, 110 insertions, 64 deletions

diff --git a/arch/arm/mach-omap2/gpmc-onenand.c b/arch/arm/mach-omap2/gpmc-onenand.c
index 916716e1da3b..29d391b273fc 100644
--- a/arch/arm/mach-omap2/gpmc-onenand.c
+++ b/arch/arm/mach-omap2/gpmc-onenand.c
@@ -16,6 +16,7 @@
 #include <linux/mtd/onenand_regs.h>
 #include <linux/io.h>
 #include <linux/platform_data/mtd-onenand-omap2.h>
+#include <linux/err.h>
 
 #include <asm/mach/flash.h>
 
@@ -25,6 +26,15 @@
 
 #define ONENAND_IO_SIZE SZ_128K
 
+#define ONENAND_FLAG_SYNCREAD   (1 << 0)
+#define ONENAND_FLAG_SYNCWRITE  (1 << 1)
+#define ONENAND_FLAG_HF         (1 << 2)
+#define ONENAND_FLAG_VHF        (1 << 3)
+
+static unsigned onenand_flags;
+static unsigned latency;
+static int fclk_offset;
+
 static struct omap_onenand_platform_data *gpmc_onenand_data;
 
 static struct resource gpmc_onenand_resource = {
@@ -38,11 +48,9 @@ static struct platform_device gpmc_onenand_device = {
         .resource       = &gpmc_onenand_resource,
 };
 
-static int omap2_onenand_set_async_mode(int cs, void __iomem *onenand_base)
+static struct gpmc_timings omap2_onenand_calc_async_timings(void)
 {
         struct gpmc_timings t;
-        u32 reg;
-        int err;
 
         const int t_cer = 15;
         const int t_avdp = 12;
@@ -55,11 +63,6 @@ static int omap2_onenand_set_async_mode(int cs, void __iomem *onenand_base)
         const int t_wpl = 40;
         const int t_wph = 30;
 
-        /* Ensure sync read and sync write are disabled */
-        reg = readw(onenand_base + ONENAND_REG_SYS_CFG1);
-        reg &= ~ONENAND_SYS_CFG1_SYNC_READ & ~ONENAND_SYS_CFG1_SYNC_WRITE;
-        writew(reg, onenand_base + ONENAND_REG_SYS_CFG1);
-
         memset(&t, 0, sizeof(t));
         t.sync_clk = 0;
         t.cs_on = 0;
@@ -86,25 +89,30 @@ static int omap2_onenand_set_async_mode(int cs, void __iomem *onenand_base)
         t.cs_wr_off = t.we_off + gpmc_round_ns_to_ticks(t_wph);
         t.wr_cycle  = t.cs_wr_off + gpmc_round_ns_to_ticks(t_cez);
 
+        return t;
+}
+
+static int gpmc_set_async_mode(int cs, struct gpmc_timings *t)
+{
         /* Configure GPMC for asynchronous read */
         gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1,
                           GPMC_CONFIG1_DEVICESIZE_16 |
                           GPMC_CONFIG1_MUXADDDATA);
 
-        err = gpmc_cs_set_timings(cs, &t);
-        if (err)
-                return err;
+        return gpmc_cs_set_timings(cs, t);
+}
+
+static void omap2_onenand_set_async_mode(void __iomem *onenand_base)
+{
+        u32 reg;
 
         /* Ensure sync read and sync write are disabled */
         reg = readw(onenand_base + ONENAND_REG_SYS_CFG1);
         reg &= ~ONENAND_SYS_CFG1_SYNC_READ & ~ONENAND_SYS_CFG1_SYNC_WRITE;
         writew(reg, onenand_base + ONENAND_REG_SYS_CFG1);
-
-        return 0;
 }
 
-static void set_onenand_cfg(void __iomem *onenand_base, int latency,
-                                int sync_read, int sync_write, int hf, int vhf)
+static void set_onenand_cfg(void __iomem *onenand_base)
 {
         u32 reg;
 
@@ -112,19 +120,19 @@ static void set_onenand_cfg(void __iomem *onenand_base, int latency,
         reg &= ~((0x7 << ONENAND_SYS_CFG1_BRL_SHIFT) | (0x7 << 9));
         reg |=  (latency << ONENAND_SYS_CFG1_BRL_SHIFT) |
                 ONENAND_SYS_CFG1_BL_16;
-        if (sync_read)
+        if (onenand_flags & ONENAND_FLAG_SYNCREAD)
                 reg |= ONENAND_SYS_CFG1_SYNC_READ;
         else
                 reg &= ~ONENAND_SYS_CFG1_SYNC_READ;
-        if (sync_write)
+        if (onenand_flags & ONENAND_FLAG_SYNCWRITE)
                 reg |= ONENAND_SYS_CFG1_SYNC_WRITE;
         else
                 reg &= ~ONENAND_SYS_CFG1_SYNC_WRITE;
-        if (hf)
+        if (onenand_flags & ONENAND_FLAG_HF)
                 reg |= ONENAND_SYS_CFG1_HF;
         else
                 reg &= ~ONENAND_SYS_CFG1_HF;
-        if (vhf)
+        if (onenand_flags & ONENAND_FLAG_VHF)
                 reg |= ONENAND_SYS_CFG1_VHF;
         else
                 reg &= ~ONENAND_SYS_CFG1_VHF;
@@ -172,9 +180,9 @@ static int omap2_onenand_get_freq(struct omap_onenand_platform_data *cfg,
         return freq;
 }
 
-static int omap2_onenand_set_sync_mode(struct omap_onenand_platform_data *cfg,
-                                        void __iomem *onenand_base,
-                                        int *freq_ptr)
+static struct gpmc_timings
+omap2_onenand_calc_sync_timings(struct omap_onenand_platform_data *cfg,
+                                int freq, bool clk_dep)
 {
         struct gpmc_timings t;
         const int t_cer  = 15;
@@ -184,29 +192,15 @@ static int omap2_onenand_set_sync_mode(struct omap_onenand_platform_data *cfg,
         const int t_wpl  = 40;
         const int t_wph  = 30;
         int min_gpmc_clk_period, t_ces, t_avds, t_avdh, t_ach, t_aavdh, t_rdyo;
-        int div, fclk_offset_ns, fclk_offset, gpmc_clk_ns, latency;
-        int first_time = 0, hf = 0, vhf = 0, sync_read = 0, sync_write = 0;
-        int err, ticks_cez;
-        int cs = cfg->cs, freq = *freq_ptr;
         u32 reg;
-        bool clk_dep = false;
-
-        if (cfg->flags & ONENAND_SYNC_READ) {
-                sync_read = 1;
-        } else if (cfg->flags & ONENAND_SYNC_READWRITE) {
-                sync_read = 1;
-                sync_write = 1;
-        } else
-                return omap2_onenand_set_async_mode(cs, onenand_base);
+        int div, fclk_offset_ns, gpmc_clk_ns;
+        int ticks_cez;
+        int cs = cfg->cs;
 
-        if (!freq) {
-                /* Very first call freq is not known */
-                err = omap2_onenand_set_async_mode(cs, onenand_base);
-                if (err)
-                        return err;
-                freq = omap2_onenand_get_freq(cfg, onenand_base, &clk_dep);
-                first_time = 1;
-        }
+        if (cfg->flags & ONENAND_SYNC_READ)
+                onenand_flags = ONENAND_FLAG_SYNCREAD;
+        else if (cfg->flags & ONENAND_SYNC_READWRITE)
+                onenand_flags = ONENAND_FLAG_SYNCREAD | ONENAND_FLAG_SYNCWRITE;
 
         switch (freq) {
         case 104:
@@ -244,19 +238,23 @@ static int omap2_onenand_set_sync_mode(struct omap_onenand_platform_data *cfg,
                 t_ach   = 9;
                 t_aavdh = 7;
                 t_rdyo  = 15;
-                sync_write = 0;
+                onenand_flags &= ~ONENAND_FLAG_SYNCWRITE;
                 break;
         }
 
         div = gpmc_cs_calc_divider(cs, min_gpmc_clk_period);
         gpmc_clk_ns = gpmc_ticks_to_ns(div);
         if (gpmc_clk_ns < 15) /* >66Mhz */
-                hf = 1;
+                onenand_flags |= ONENAND_FLAG_HF;
+        else
+                onenand_flags &= ~ONENAND_FLAG_HF;
         if (gpmc_clk_ns < 12) /* >83Mhz */
-                vhf = 1;
-        if (vhf)
+                onenand_flags |= ONENAND_FLAG_VHF;
+        else
+                onenand_flags &= ~ONENAND_FLAG_VHF;
+        if (onenand_flags & ONENAND_FLAG_VHF)
                 latency = 8;
-        else if (hf)
+        else if (onenand_flags & ONENAND_FLAG_HF)
                 latency = 6;
         else if (gpmc_clk_ns >= 25) /* 40 MHz*/
                 latency = 3;
@@ -279,9 +277,8 @@ static int omap2_onenand_set_sync_mode(struct omap_onenand_platform_data *cfg,
                 }
         }
 
-        if (first_time)
-                set_onenand_cfg(onenand_base, latency,
-                                        sync_read, sync_write, hf, vhf);
+        /* Set synchronous read timings */
+        memset(&t, 0, sizeof(t));
 
         if (div == 1) {
                 reg = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG2);
@@ -307,8 +304,6 @@ static int omap2_onenand_set_sync_mode(struct omap_onenand_platform_data *cfg,
                 gpmc_cs_write_reg(cs, GPMC_CS_CONFIG4, reg);
         }
 
-        /* Set synchronous read timings */
-        memset(&t, 0, sizeof(t));
         t.sync_clk = min_gpmc_clk_period;
         t.cs_on = 0;
         t.adv_on = 0;
@@ -330,7 +325,7 @@ static int omap2_onenand_set_sync_mode(struct omap_onenand_platform_data *cfg,
                      ticks_cez);
 
         /* Write */
-        if (sync_write) {
+        if (onenand_flags & ONENAND_FLAG_SYNCWRITE) {
                 t.adv_wr_off = t.adv_rd_off;
                 t.we_on  = 0;
                 t.we_off = t.cs_rd_off;
@@ -355,6 +350,14 @@ static int omap2_onenand_set_sync_mode(struct omap_onenand_platform_data *cfg,
                 }
         }
 
+        return t;
+}
+
+static int gpmc_set_sync_mode(int cs, struct gpmc_timings *t)
+{
+        unsigned sync_read = onenand_flags & ONENAND_FLAG_SYNCREAD;
+        unsigned sync_write = onenand_flags & ONENAND_FLAG_SYNCWRITE;
+
         /* Configure GPMC for synchronous read */
         gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1,
                           GPMC_CONFIG1_WRAPBURST_SUPP |
@@ -371,11 +374,47 @@ static int omap2_onenand_set_sync_mode(struct omap_onenand_platform_data *cfg,
                           GPMC_CONFIG1_DEVICETYPE_NOR |
                           GPMC_CONFIG1_MUXADDDATA);
 
-        err = gpmc_cs_set_timings(cs, &t);
-        if (err)
-                return err;
+        return gpmc_cs_set_timings(cs, t);
+}
+
+static int omap2_onenand_setup_async(void __iomem *onenand_base)
+{
+        struct gpmc_timings t;
+        int ret;
+
+        omap2_onenand_set_async_mode(onenand_base);
+
+        t = omap2_onenand_calc_async_timings();
+
+        ret = gpmc_set_async_mode(gpmc_onenand_data->cs, &t);
+        if (IS_ERR_VALUE(ret))
+                return ret;
+
+        omap2_onenand_set_async_mode(onenand_base);
+
+        return 0;
+}
+
+static int omap2_onenand_setup_sync(void __iomem *onenand_base, int *freq_ptr)
+{
+        int ret, freq = *freq_ptr;
+        struct gpmc_timings t;
+        bool clk_dep = false;
+
+        if (!freq) {
+                /* Very first call freq is not known */
+                freq = omap2_onenand_get_freq(gpmc_onenand_data,
+                                                onenand_base, &clk_dep);
+                set_onenand_cfg(onenand_base);
+        }
+
+        t = omap2_onenand_calc_sync_timings(gpmc_onenand_data, freq, clk_dep);
 
-        set_onenand_cfg(onenand_base, latency, sync_read, sync_write, hf, vhf);
+        ret = gpmc_set_sync_mode(gpmc_onenand_data->cs, &t);
+        if (IS_ERR_VALUE(ret))
+                return ret;
+
+        set_onenand_cfg(onenand_base);
 
         *freq_ptr = freq;
 
@@ -385,15 +424,22 @@ static int omap2_onenand_set_sync_mode(struct omap_onenand_platform_data *cfg,
 static int gpmc_onenand_setup(void __iomem *onenand_base, int *freq_ptr)
 {
         struct device *dev = &gpmc_onenand_device.dev;
+        unsigned l = ONENAND_SYNC_READ | ONENAND_SYNC_READWRITE;
+        int ret;
 
-        /* Set sync timings in GPMC */
-        if (omap2_onenand_set_sync_mode(gpmc_onenand_data, onenand_base,
-                        freq_ptr) < 0) {
-                dev_err(dev, "Unable to set synchronous mode\n");
-                return -EINVAL;
+        ret = omap2_onenand_setup_async(onenand_base);
+        if (ret) {
+                dev_err(dev, "unable to set to async mode\n");
+                return ret;
         }
 
-        return 0;
+        if (!(gpmc_onenand_data->flags & l))
+                return 0;
+
+        ret = omap2_onenand_setup_sync(onenand_base, freq_ptr);
+        if (ret)
+                dev_err(dev, "unable to set to sync mode\n");
+        return ret;
 }
 
 void __init gpmc_onenand_init(struct omap_onenand_platform_data *_onenand_data)