mfd: support stmpe1801 18 bits enhanced port expander

Provides support for 1801 variant of stmpe gpio port expanders.
This chip has 18 gpios configurable as GPI, GPO, keypad matrix,
special key or dedicated key function.

Note that special/dedicated key function is not supported yet.

Signed-off-by: Jean-Nicolas Graux <jean-nicolas.graux@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 96 insertions, 1 deletions

diff --git a/drivers/mfd/stmpe.c b/drivers/mfd/stmpe.c
index bc8587777993..bbccd514d3ec 100644
--- a/drivers/mfd/stmpe.c
+++ b/drivers/mfd/stmpe.c
@@ -19,6 +19,7 @@
 #include <linux/pm.h>
 #include <linux/slab.h>
 #include <linux/mfd/core.h>
+#include <linux/delay.h>
 #include "stmpe.h"
 
 static int __stmpe_enable(struct stmpe *stmpe, unsigned int blocks)
@@ -643,6 +644,88 @@ static struct stmpe_variant_info stmpe1601 = {
 };
 
 /*
+ * STMPE1801
+ */
+static const u8 stmpe1801_regs[] = {
+        [STMPE_IDX_CHIP_ID]     = STMPE1801_REG_CHIP_ID,
+        [STMPE_IDX_ICR_LSB]     = STMPE1801_REG_INT_CTRL_LOW,
+        [STMPE_IDX_IER_LSB]     = STMPE1801_REG_INT_EN_MASK_LOW,
+        [STMPE_IDX_ISR_LSB]     = STMPE1801_REG_INT_STA_LOW,
+        [STMPE_IDX_GPMR_LSB]    = STMPE1801_REG_GPIO_MP_LOW,
+        [STMPE_IDX_GPSR_LSB]    = STMPE1801_REG_GPIO_SET_LOW,
+        [STMPE_IDX_GPCR_LSB]    = STMPE1801_REG_GPIO_CLR_LOW,
+        [STMPE_IDX_GPDR_LSB]    = STMPE1801_REG_GPIO_SET_DIR_LOW,
+        [STMPE_IDX_GPRER_LSB]   = STMPE1801_REG_GPIO_RE_LOW,
+        [STMPE_IDX_GPFER_LSB]   = STMPE1801_REG_GPIO_FE_LOW,
+        [STMPE_IDX_IEGPIOR_LSB] = STMPE1801_REG_INT_EN_GPIO_MASK_LOW,
+        [STMPE_IDX_ISGPIOR_LSB] = STMPE1801_REG_INT_STA_GPIO_LOW,
+};
+
+static struct stmpe_variant_block stmpe1801_blocks[] = {
+        {
+                .cell   = &stmpe_gpio_cell,
+                .irq    = STMPE1801_IRQ_GPIOC,
+                .block  = STMPE_BLOCK_GPIO,
+        },
+        {
+                .cell   = &stmpe_keypad_cell,
+                .irq    = STMPE1801_IRQ_KEYPAD,
+                .block  = STMPE_BLOCK_KEYPAD,
+        },
+};
+
+static int stmpe1801_enable(struct stmpe *stmpe, unsigned int blocks,
+                            bool enable)
+{
+        unsigned int mask = 0;
+        if (blocks & STMPE_BLOCK_GPIO)
+                mask |= STMPE1801_MSK_INT_EN_GPIO;
+
+        if (blocks & STMPE_BLOCK_KEYPAD)
+                mask |= STMPE1801_MSK_INT_EN_KPC;
+
+        return __stmpe_set_bits(stmpe, STMPE1801_REG_INT_EN_MASK_LOW, mask,
+                                enable ? mask : 0);
+}
+
+static int stmpe1801_reset(struct stmpe *stmpe)
+{
+        unsigned long timeout;
+        int ret = 0;
+
+        ret = __stmpe_set_bits(stmpe, STMPE1801_REG_SYS_CTRL,
+                STMPE1801_MSK_SYS_CTRL_RESET, STMPE1801_MSK_SYS_CTRL_RESET);
+        if (ret < 0)
+                return ret;
+
+        timeout = jiffies + msecs_to_jiffies(100);
+        while (time_before(jiffies, timeout)) {
+                ret = __stmpe_reg_read(stmpe, STMPE1801_REG_SYS_CTRL);
+                if (ret < 0)
+                        return ret;
+                if (!(ret & STMPE1801_MSK_SYS_CTRL_RESET))
+                        return 0;
+                usleep_range(100, 200);
+        };
+        return -EIO;
+}
+
+static struct stmpe_variant_info stmpe1801 = {
+        .name           = "stmpe1801",
+        .id_val         = STMPE1801_ID,
+        .id_mask        = 0xfff0,
+        .num_gpios      = 18,
+        .af_bits        = 0,
+        .regs           = stmpe1801_regs,
+        .blocks         = stmpe1801_blocks,
+        .num_blocks     = ARRAY_SIZE(stmpe1801_blocks),
+        .num_irqs       = STMPE1801_NR_INTERNAL_IRQS,
+        .enable         = stmpe1801_enable,
+        /* stmpe1801 do not have any gpio alternate function */
+        .get_altfunc    = NULL,
+};
+
+/*
  * STMPE24XX
  */
 
@@ -740,6 +823,7 @@ static struct stmpe_variant_info *stmpe_variant_info[STMPE_NBR_PARTS] = {
         [STMPE801]      = &stmpe801,
         [STMPE811]      = &stmpe811,
         [STMPE1601]     = &stmpe1601,
+        [STMPE1801]     = &stmpe1801,
         [STMPE2401]     = &stmpe2401,
         [STMPE2403]     = &stmpe2403,
 };
@@ -759,7 +843,7 @@ static irqreturn_t stmpe_irq(int irq, void *data)
         struct stmpe *stmpe = data;
         struct stmpe_variant_info *variant = stmpe->variant;
         int num = DIV_ROUND_UP(variant->num_irqs, 8);
-        u8 israddr = stmpe->regs[STMPE_IDX_ISR_MSB];
+        u8 israddr;
         u8 isr[num];
         int ret;
         int i;
@@ -771,6 +855,11 @@ static irqreturn_t stmpe_irq(int irq, void *data)
                 return IRQ_HANDLED;
         }
 
+        if (variant->id_val == STMPE1801_ID)
+                israddr = stmpe->regs[STMPE_IDX_ISR_LSB];
+        else
+                israddr = stmpe->regs[STMPE_IDX_ISR_MSB];
+
         ret = stmpe_block_read(stmpe, israddr, num, isr);
         if (ret < 0)
                 return IRQ_NONE;
@@ -938,6 +1027,12 @@ static int stmpe_chip_init(struct stmpe *stmpe)
         if (ret)
                 return ret;
 
+        if (id == STMPE1801_ID) {
+                ret =  stmpe1801_reset(stmpe);
+                if (ret < 0)
+                        return ret;
+        }
+
         if (stmpe->irq >= 0) {
                 if (id == STMPE801_ID)
                         icr = STMPE801_REG_SYS_CTRL_INT_EN;