counter: 104-quad-8: Implement and utilize register structures

Reduce magic numbers and improve code readability by implementing and
utilizing named register data structures.

Link: https://lore.kernel.org/r/20220707171709.36010-1-william.gray@linaro.org/
Cc: Syed Nayyar Waris <syednwaris@gmail.com>
Tested-by: Fred Eckert <Frede@cmslaser.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Link: https://lore.kernel.org/r/285fdc7c03892251f50bdbf2c28c19998243a6a3.1657813472.git.william.gray@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
index 43dde9a..62c2b7a 100644 (file)
--- a/drivers/counter/104-quad-8.c
+++ b/drivers/counter/104-quad-8.c
@@ -34,6 +34,36 @@ MODULE_PARM_DESC(irq, "ACCES 104-QUAD-8 interrupt line numbers");
 #define QUAD8_NUM_COUNTERS 8
 
 /**
+ * struct channel_reg - channel register structure
+ * @data:      Count data
+ * @control:   Channel flags and control
+ */
+struct channel_reg {
+       u8 data;
+       u8 control;
+};
+
+/**
+ * struct quad8_reg - device register structure
+ * @channel:           quadrature counter data and control
+ * @interrupt_status:  channel interrupt status
+ * @channel_oper:      enable/reset counters and interrupt functions
+ * @index_interrupt:   enable channel interrupts
+ * @reserved:          reserved for Factory Use
+ * @index_input_levels:        index signal logical input level
+ * @cable_status:      differential encoder cable status
+ */
+struct quad8_reg {
+       struct channel_reg channel[QUAD8_NUM_COUNTERS];
+       u8 interrupt_status;
+       u8 channel_oper;
+       u8 index_interrupt;
+       u8 reserved[3];
+       u8 index_input_levels;
+       u8 cable_status;
+};
+
+/**
  * struct quad8 - device private data structure
  * @lock:              lock to prevent clobbering device states during R/W ops
  * @counter:           instance of the counter_device
@@ -48,7 +78,7 @@ MODULE_PARM_DESC(irq, "ACCES 104-QUAD-8 interrupt line numbers");
  * @synchronous_mode:  array of index function synchronous mode configurations
  * @index_polarity:    array of index function polarity configurations
  * @cable_fault_enable:        differential encoder cable status enable configurations
- * @base:              base port address of the device
+ * @reg:               I/O address offset for the device registers
  */
 struct quad8 {
        spinlock_t lock;
@@ -63,14 +93,9 @@ struct quad8 {
        unsigned int synchronous_mode[QUAD8_NUM_COUNTERS];
        unsigned int index_polarity[QUAD8_NUM_COUNTERS];
        unsigned int cable_fault_enable;
-       void __iomem *base;
+       struct quad8_reg __iomem *reg;
 };
 
-#define QUAD8_REG_INTERRUPT_STATUS 0x10
-#define QUAD8_REG_CHAN_OP 0x11
-#define QUAD8_REG_INDEX_INTERRUPT 0x12
-#define QUAD8_REG_INDEX_INPUT_LEVELS 0x16
-#define QUAD8_DIFF_ENCODER_CABLE_STATUS 0x17
 /* Borrow Toggle flip-flop */
 #define QUAD8_FLAG_BT BIT(0)
 /* Carry Toggle flip-flop */
@@ -118,8 +143,7 @@ static int quad8_signal_read(struct counter_device *counter,
        if (signal->id < 16)
                return -EINVAL;
 
-       state = ioread8(priv->base + QUAD8_REG_INDEX_INPUT_LEVELS) &
-               BIT(signal->id - 16);
+       state = ioread8(&priv->reg->index_input_levels) & BIT(signal->id - 16);
 
        *level = (state) ? COUNTER_SIGNAL_LEVEL_HIGH : COUNTER_SIGNAL_LEVEL_LOW;
 
@@ -130,14 +154,14 @@ static int quad8_count_read(struct counter_device *counter,
                            struct counter_count *count, u64 *val)
 {
        struct quad8 *const priv = counter_priv(counter);
-       void __iomem *const base_offset = priv->base + 2 * count->id;
+       struct channel_reg __iomem *const chan = priv->reg->channel + count->id;
        unsigned int flags;
        unsigned int borrow;
        unsigned int carry;
        unsigned long irqflags;
        int i;
 
-       flags = ioread8(base_offset + 1);
+       flags = ioread8(&chan->control);
        borrow = flags & QUAD8_FLAG_BT;
        carry = !!(flags & QUAD8_FLAG_CT);
 
@@ -148,10 +172,10 @@ static int quad8_count_read(struct counter_device *counter,
 
        /* Reset Byte Pointer; transfer Counter to Output Latch */
        iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_CNTR_OUT,
-                base_offset + 1);
+                &chan->control);
 
        for (i = 0; i < 3; i++)
-               *val |= (unsigned long)ioread8(base_offset) << (8 * i);
+               *val |= (unsigned long)ioread8(&chan->data) << (8 * i);
 
        spin_unlock_irqrestore(&priv->lock, irqflags);
 
@@ -162,7 +186,7 @@ static int quad8_count_write(struct counter_device *counter,
                             struct counter_count *count, u64 val)
 {
        struct quad8 *const priv = counter_priv(counter);
-       void __iomem *const base_offset = priv->base + 2 * count->id;
+       struct channel_reg __iomem *const chan = priv->reg->channel + count->id;
        unsigned long irqflags;
        int i;
 
@@ -173,27 +197,27 @@ static int quad8_count_write(struct counter_device *counter,
        spin_lock_irqsave(&priv->lock, irqflags);
 
        /* Reset Byte Pointer */
-       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
+       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, &chan->control);
 
        /* Counter can only be set via Preset Register */
        for (i = 0; i < 3; i++)
-               iowrite8(val >> (8 * i), base_offset);
+               iowrite8(val >> (8 * i), &chan->data);
 
        /* Transfer Preset Register to Counter */
-       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_PRESET_CNTR, base_offset + 1);
+       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_PRESET_CNTR, &chan->control);
 
        /* Reset Byte Pointer */
-       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
+       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, &chan->control);
 
        /* Set Preset Register back to original value */
        val = priv->preset[count->id];
        for (i = 0; i < 3; i++)
-               iowrite8(val >> (8 * i), base_offset);
+               iowrite8(val >> (8 * i), &chan->data);
 
        /* Reset Borrow, Carry, Compare, and Sign flags */
-       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1);
+       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, &chan->control);
        /* Reset Error flag */
-       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1);
+       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, &chan->control);
 
        spin_unlock_irqrestore(&priv->lock, irqflags);
 
@@ -246,7 +270,7 @@ static int quad8_function_write(struct counter_device *counter,
        unsigned int *const quadrature_mode = priv->quadrature_mode + id;
        unsigned int *const scale = priv->quadrature_scale + id;
        unsigned int *const synchronous_mode = priv->synchronous_mode + id;
-       void __iomem *const base_offset = priv->base + 2 * id + 1;
+       u8 __iomem *const control = &priv->reg->channel[id].control;
        unsigned long irqflags;
        unsigned int mode_cfg;
        unsigned int idr_cfg;
@@ -266,7 +290,7 @@ static int quad8_function_write(struct counter_device *counter,
                if (*synchronous_mode) {
                        *synchronous_mode = 0;
                        /* Disable synchronous function mode */
-                       iowrite8(QUAD8_CTR_IDR | idr_cfg, base_offset);
+                       iowrite8(QUAD8_CTR_IDR | idr_cfg, control);
                }
        } else {
                *quadrature_mode = 1;
@@ -292,7 +316,7 @@ static int quad8_function_write(struct counter_device *counter,
        }
 
        /* Load mode configuration to Counter Mode Register */
-       iowrite8(QUAD8_CTR_CMR | mode_cfg, base_offset);
+       iowrite8(QUAD8_CTR_CMR | mode_cfg, control);
 
        spin_unlock_irqrestore(&priv->lock, irqflags);
 
@@ -305,7 +329,7 @@ static int quad8_direction_read(struct counter_device *counter,
 {
        const struct quad8 *const priv = counter_priv(counter);
        unsigned int ud_flag;
-       void __iomem *const flag_addr = priv->base + 2 * count->id + 1;
+       u8 __iomem *const flag_addr = &priv->reg->channel[count->id].control;
 
        /* U/D flag: nonzero = up, zero = down */
        ud_flag = ioread8(flag_addr) & QUAD8_FLAG_UD;
@@ -402,7 +426,6 @@ static int quad8_events_configure(struct counter_device *counter)
        struct counter_event_node *event_node;
        unsigned int next_irq_trigger;
        unsigned long ior_cfg;
-       void __iomem *base_offset;
 
        spin_lock_irqsave(&priv->lock, irqflags);
 
@@ -437,14 +460,14 @@ static int quad8_events_configure(struct counter_device *counter)
                ior_cfg = priv->ab_enable[event_node->channel] |
                          priv->preset_enable[event_node->channel] << 1 |
                          priv->irq_trigger[event_node->channel] << 3;
-               base_offset = priv->base + 2 * event_node->channel + 1;
-               iowrite8(QUAD8_CTR_IOR | ior_cfg, base_offset);
+               iowrite8(QUAD8_CTR_IOR | ior_cfg,
+                        &priv->reg->channel[event_node->channel].control);
 
                /* Enable IRQ line */
                irq_enabled |= BIT(event_node->channel);
        }
 
-       iowrite8(irq_enabled, priv->base + QUAD8_REG_INDEX_INTERRUPT);
+       iowrite8(irq_enabled, &priv->reg->index_interrupt);
 
        spin_unlock_irqrestore(&priv->lock, irqflags);
 
@@ -508,7 +531,7 @@ static int quad8_index_polarity_set(struct counter_device *counter,
 {
        struct quad8 *const priv = counter_priv(counter);
        const size_t channel_id = signal->id - 16;
-       void __iomem *const base_offset = priv->base + 2 * channel_id + 1;
+       u8 __iomem *const control = &priv->reg->channel[channel_id].control;
        unsigned long irqflags;
        unsigned int idr_cfg = index_polarity << 1;
 
@@ -519,7 +542,7 @@ static int quad8_index_polarity_set(struct counter_device *counter,
        priv->index_polarity[channel_id] = index_polarity;
 
        /* Load Index Control configuration to Index Control Register */
-       iowrite8(QUAD8_CTR_IDR | idr_cfg, base_offset);
+       iowrite8(QUAD8_CTR_IDR | idr_cfg, control);
 
        spin_unlock_irqrestore(&priv->lock, irqflags);
 
@@ -549,7 +572,7 @@ static int quad8_synchronous_mode_set(struct counter_device *counter,
 {
        struct quad8 *const priv = counter_priv(counter);
        const size_t channel_id = signal->id - 16;
-       void __iomem *const base_offset = priv->base + 2 * channel_id + 1;
+       u8 __iomem *const control = &priv->reg->channel[channel_id].control;
        unsigned long irqflags;
        unsigned int idr_cfg = synchronous_mode;
 
@@ -566,7 +589,7 @@ static int quad8_synchronous_mode_set(struct counter_device *counter,
        priv->synchronous_mode[channel_id] = synchronous_mode;
 
        /* Load Index Control configuration to Index Control Register */
-       iowrite8(QUAD8_CTR_IDR | idr_cfg, base_offset);
+       iowrite8(QUAD8_CTR_IDR | idr_cfg, control);
 
        spin_unlock_irqrestore(&priv->lock, irqflags);
 
@@ -614,7 +637,7 @@ static int quad8_count_mode_write(struct counter_device *counter,
        struct quad8 *const priv = counter_priv(counter);
        unsigned int count_mode;
        unsigned int mode_cfg;
-       void __iomem *const base_offset = priv->base + 2 * count->id + 1;
+       u8 __iomem *const control = &priv->reg->channel[count->id].control;
        unsigned long irqflags;
 
        /* Map Generic Counter count mode to 104-QUAD-8 count mode */
@@ -648,7 +671,7 @@ static int quad8_count_mode_write(struct counter_device *counter,
                mode_cfg |= (priv->quadrature_scale[count->id] + 1) << 3;
 
        /* Load mode configuration to Counter Mode Register */
-       iowrite8(QUAD8_CTR_CMR | mode_cfg, base_offset);
+       iowrite8(QUAD8_CTR_CMR | mode_cfg, control);
 
        spin_unlock_irqrestore(&priv->lock, irqflags);
 
@@ -669,7 +692,7 @@ static int quad8_count_enable_write(struct counter_device *counter,
                                    struct counter_count *count, u8 enable)
 {
        struct quad8 *const priv = counter_priv(counter);
-       void __iomem *const base_offset = priv->base + 2 * count->id;
+       u8 __iomem *const control = &priv->reg->channel[count->id].control;
        unsigned long irqflags;
        unsigned int ior_cfg;
 
@@ -681,7 +704,7 @@ static int quad8_count_enable_write(struct counter_device *counter,
                  priv->irq_trigger[count->id] << 3;
 
        /* Load I/O control configuration */
-       iowrite8(QUAD8_CTR_IOR | ior_cfg, base_offset + 1);
+       iowrite8(QUAD8_CTR_IOR | ior_cfg, control);
 
        spin_unlock_irqrestore(&priv->lock, irqflags);
 
@@ -697,9 +720,9 @@ static int quad8_error_noise_get(struct counter_device *counter,
                                 struct counter_count *count, u32 *noise_error)
 {
        const struct quad8 *const priv = counter_priv(counter);
-       void __iomem *const base_offset = priv->base + 2 * count->id + 1;
+       u8 __iomem *const flag_addr = &priv->reg->channel[count->id].control;
 
-       *noise_error = !!(ioread8(base_offset) & QUAD8_FLAG_E);
+       *noise_error = !!(ioread8(flag_addr) & QUAD8_FLAG_E);
 
        return 0;
 }
@@ -717,17 +740,17 @@ static int quad8_count_preset_read(struct counter_device *counter,
 static void quad8_preset_register_set(struct quad8 *const priv, const int id,
                                      const unsigned int preset)
 {
-       void __iomem *const base_offset = priv->base + 2 * id;
+       struct channel_reg __iomem *const chan = priv->reg->channel + id;
        int i;
 
        priv->preset[id] = preset;
 
        /* Reset Byte Pointer */
-       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
+       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, &chan->control);
 
        /* Set Preset Register */
        for (i = 0; i < 3; i++)
-               iowrite8(preset >> (8 * i), base_offset);
+               iowrite8(preset >> (8 * i), &chan->data);
 }
 
 static int quad8_count_preset_write(struct counter_device *counter,
@@ -816,7 +839,7 @@ static int quad8_count_preset_enable_write(struct counter_device *counter,
                                           u8 preset_enable)
 {
        struct quad8 *const priv = counter_priv(counter);
-       void __iomem *const base_offset = priv->base + 2 * count->id + 1;
+       u8 __iomem *const control = &priv->reg->channel[count->id].control;
        unsigned long irqflags;
        unsigned int ior_cfg;
 
@@ -831,7 +854,7 @@ static int quad8_count_preset_enable_write(struct counter_device *counter,
                  priv->irq_trigger[count->id] << 3;
 
        /* Load I/O control configuration to Input / Output Control Register */
-       iowrite8(QUAD8_CTR_IOR | ior_cfg, base_offset);
+       iowrite8(QUAD8_CTR_IOR | ior_cfg, control);
 
        spin_unlock_irqrestore(&priv->lock, irqflags);
 
@@ -858,7 +881,7 @@ static int quad8_signal_cable_fault_read(struct counter_device *counter,
        }
 
        /* Logic 0 = cable fault */
-       status = ioread8(priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS);
+       status = ioread8(&priv->reg->cable_status);
 
        spin_unlock_irqrestore(&priv->lock, irqflags);
 
@@ -899,8 +922,7 @@ static int quad8_signal_cable_fault_enable_write(struct counter_device *counter,
        /* Enable is active low in Differential Encoder Cable Status register */
        cable_fault_enable = ~priv->cable_fault_enable;
 
-       iowrite8(cable_fault_enable,
-                priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS);
+       iowrite8(cable_fault_enable, &priv->reg->cable_status);
 
        spin_unlock_irqrestore(&priv->lock, irqflags);
 
@@ -924,7 +946,7 @@ static int quad8_signal_fck_prescaler_write(struct counter_device *counter,
 {
        struct quad8 *const priv = counter_priv(counter);
        const size_t channel_id = signal->id / 2;
-       void __iomem *const base_offset = priv->base + 2 * channel_id;
+       struct channel_reg __iomem *const chan = priv->reg->channel + channel_id;
        unsigned long irqflags;
 
        spin_lock_irqsave(&priv->lock, irqflags);
@@ -932,12 +954,12 @@ static int quad8_signal_fck_prescaler_write(struct counter_device *counter,
        priv->fck_prescaler[channel_id] = prescaler;
 
        /* Reset Byte Pointer */
-       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
+       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, &chan->control);
 
        /* Set filter clock factor */
-       iowrite8(prescaler, base_offset);
+       iowrite8(prescaler, &chan->data);
        iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_PRESET_PSC,
-                base_offset + 1);
+                &chan->control);
 
        spin_unlock_irqrestore(&priv->lock, irqflags);
 
@@ -1085,12 +1107,11 @@ static irqreturn_t quad8_irq_handler(int irq, void *private)
 {
        struct counter_device *counter = private;
        struct quad8 *const priv = counter_priv(counter);
-       void __iomem *const base = priv->base;
        unsigned long irq_status;
        unsigned long channel;
        u8 event;
 
-       irq_status = ioread8(base + QUAD8_REG_INTERRUPT_STATUS);
+       irq_status = ioread8(&priv->reg->interrupt_status);
        if (!irq_status)
                return IRQ_NONE;
 
@@ -1119,36 +1140,36 @@ static irqreturn_t quad8_irq_handler(int irq, void *private)
        }
 
        /* Clear pending interrupts on device */
-       iowrite8(QUAD8_CHAN_OP_ENABLE_INTERRUPT_FUNC, base + QUAD8_REG_CHAN_OP);
+       iowrite8(QUAD8_CHAN_OP_ENABLE_INTERRUPT_FUNC, &priv->reg->channel_oper);
 
        return IRQ_HANDLED;
 }
 
-static void quad8_init_counter(void __iomem *const base_offset)
+static void quad8_init_counter(struct channel_reg __iomem *const chan)
 {
        unsigned long i;
 
        /* Reset Byte Pointer */
-       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
+       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, &chan->control);
        /* Reset filter clock factor */
-       iowrite8(0, base_offset);
+       iowrite8(0, &chan->data);
        iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_PRESET_PSC,
-                base_offset + 1);
+                &chan->control);
        /* Reset Byte Pointer */
-       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1);
+       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, &chan->control);
        /* Reset Preset Register */
        for (i = 0; i < 3; i++)
-               iowrite8(0x00, base_offset);
+               iowrite8(0x00, &chan->data);
        /* Reset Borrow, Carry, Compare, and Sign flags */
-       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, base_offset + 1);
+       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_FLAGS, &chan->control);
        /* Reset Error flag */
-       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1);
+       iowrite8(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, &chan->control);
        /* Binary encoding; Normal count; non-quadrature mode */
-       iowrite8(QUAD8_CTR_CMR, base_offset + 1);
+       iowrite8(QUAD8_CTR_CMR, &chan->control);
        /* Disable A and B inputs; preset on index; FLG1 as Carry */
-       iowrite8(QUAD8_CTR_IOR, base_offset + 1);
+       iowrite8(QUAD8_CTR_IOR, &chan->control);
        /* Disable index function; negative index polarity */
-       iowrite8(QUAD8_CTR_IDR, base_offset + 1);
+       iowrite8(QUAD8_CTR_IDR, &chan->control);
 }
 
 static int quad8_probe(struct device *dev, unsigned int id)
@@ -1169,8 +1190,8 @@ static int quad8_probe(struct device *dev, unsigned int id)
                return -ENOMEM;
        priv = counter_priv(counter);
 
-       priv->base = devm_ioport_map(dev, base[id], QUAD8_EXTENT);
-       if (!priv->base)
+       priv->reg = devm_ioport_map(dev, base[id], QUAD8_EXTENT);
+       if (!priv->reg)
                return -ENOMEM;
 
        /* Initialize Counter device and driver data */
@@ -1185,17 +1206,16 @@ static int quad8_probe(struct device *dev, unsigned int id)
        spin_lock_init(&priv->lock);
 
        /* Reset Index/Interrupt Register */
-       iowrite8(0x00, priv->base + QUAD8_REG_INDEX_INTERRUPT);
+       iowrite8(0x00, &priv->reg->index_interrupt);
        /* Reset all counters and disable interrupt function */
-       iowrite8(QUAD8_CHAN_OP_RESET_COUNTERS, priv->base + QUAD8_REG_CHAN_OP);
+       iowrite8(QUAD8_CHAN_OP_RESET_COUNTERS, &priv->reg->channel_oper);
        /* Set initial configuration for all counters */
        for (i = 0; i < QUAD8_NUM_COUNTERS; i++)
-               quad8_init_counter(priv->base + 2 * i);
+               quad8_init_counter(priv->reg->channel + i);
        /* Disable Differential Encoder Cable Status for all channels */
-       iowrite8(0xFF, priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS);
+       iowrite8(0xFF, &priv->reg->cable_status);
        /* Enable all counters and enable interrupt function */
-       iowrite8(QUAD8_CHAN_OP_ENABLE_INTERRUPT_FUNC,
-                priv->base + QUAD8_REG_CHAN_OP);
+       iowrite8(QUAD8_CHAN_OP_ENABLE_INTERRUPT_FUNC, &priv->reg->channel_oper);
 
        err = devm_request_irq(&counter->dev, irq[id], quad8_irq_handler,
                               IRQF_SHARED, counter->name, counter);