uart: pl011: Add support to ZTE ZX296702 uart

Support ZTE uart with some registers differing offset.
Probe as platform device for not AMBA IP ID is
available on ZTE uart.

Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 197 insertions, 16 deletions

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 687b1ea294b7..ed299b9e6375 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -47,12 +47,12 @@ config SERIAL_AMBA_PL010_CONSOLE
 
 config SERIAL_AMBA_PL011
         tristate "ARM AMBA PL011 serial port support"
-        depends on ARM_AMBA
+        depends on ARM_AMBA || SOC_ZX296702
         select SERIAL_CORE
         help
           This selects the ARM(R) AMBA(R) PrimeCell PL011 UART.  If you have
           an Integrator/PP2, Integrator/CP or Versatile platform, say Y or M
-          here.
+          here. Say Y or M if you have SOC_ZX296702.
 
           If unsure, say N.
 
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 017443d092c1..2af09ab153b6 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -74,6 +74,10 @@
 /* There is by now at least one vendor with differing details, so handle it */
 struct vendor_data {
         unsigned int            ifls;
+        unsigned int            fr_busy;
+        unsigned int            fr_dsr;
+        unsigned int            fr_cts;
+        unsigned int            fr_ri;
         unsigned int            lcrh_tx;
         unsigned int            lcrh_rx;
         u16                     *reg_lut;
@@ -127,6 +131,7 @@ static u16 arm_reg[] = {
         [REG_DMACR]             = UART011_DMACR,
 };
 
+#ifdef CONFIG_ARM_AMBA
 static unsigned int get_fifosize_arm(struct amba_device *dev)
 {
         return amba_rev(dev) < 3 ? 16 : 32;
@@ -134,6 +139,10 @@ static unsigned int get_fifosize_arm(struct amba_device *dev)
 
 static struct vendor_data vendor_arm = {
         .ifls                   = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
+        .fr_busy                = UART01x_FR_BUSY,
+        .fr_dsr                 = UART01x_FR_DSR,
+        .fr_cts                 = UART01x_FR_CTS,
+        .fr_ri                  = UART011_FR_RI,
         .lcrh_tx                = REG_LCRH,
         .lcrh_rx                = REG_LCRH,
         .reg_lut                = arm_reg,
@@ -144,8 +153,13 @@ static struct vendor_data vendor_arm = {
         .fixed_options          = false,
         .get_fifosize           = get_fifosize_arm,
 };
+#endif
 
 static struct vendor_data vendor_sbsa = {
+        .fr_busy                = UART01x_FR_BUSY,
+        .fr_dsr                 = UART01x_FR_DSR,
+        .fr_cts                 = UART01x_FR_CTS,
+        .fr_ri                  = UART011_FR_RI,
         .reg_lut                = arm_reg,
         .oversampling           = false,
         .dma_threshold          = false,
@@ -154,6 +168,7 @@ static struct vendor_data vendor_sbsa = {
         .fixed_options          = true,
 };
 
+#ifdef CONFIG_ARM_AMBA
 static u16 st_reg[] = {
         [REG_DR]                = UART01x_DR,
         [REG_RSR]               = UART01x_RSR,
@@ -180,6 +195,10 @@ static unsigned int get_fifosize_st(struct amba_device *dev)
 
 static struct vendor_data vendor_st = {
         .ifls                   = UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF,
+        .fr_busy                = UART01x_FR_BUSY,
+        .fr_dsr                 = UART01x_FR_DSR,
+        .fr_cts                 = UART01x_FR_CTS,
+        .fr_ri                  = UART011_FR_RI,
         .lcrh_tx                = REG_LCRH,
         .lcrh_rx                = REG_ST_LCRH_RX,
         .reg_lut                = st_reg,
@@ -190,6 +209,43 @@ static struct vendor_data vendor_st = {
         .fixed_options          = false,
         .get_fifosize           = get_fifosize_st,
 };
+#endif
+
+#ifdef CONFIG_SOC_ZX296702
+static u16 zte_reg[] = {
+        [REG_DR]                = ZX_UART01x_DR,
+        [REG_RSR]               = UART01x_RSR,
+        [REG_ST_DMAWM]          = ST_UART011_DMAWM,
+        [REG_FR]                = ZX_UART01x_FR,
+        [REG_ST_LCRH_RX]        = ST_UART011_LCRH_RX,
+        [REG_ILPR]              = UART01x_ILPR,
+        [REG_IBRD]              = UART011_IBRD,
+        [REG_FBRD]              = UART011_FBRD,
+        [REG_LCRH]              = ZX_UART011_LCRH_TX,
+        [REG_CR]                = ZX_UART011_CR,
+        [REG_IFLS]              = ZX_UART011_IFLS,
+        [REG_IMSC]              = ZX_UART011_IMSC,
+        [REG_RIS]               = ZX_UART011_RIS,
+        [REG_MIS]               = ZX_UART011_MIS,
+        [REG_ICR]               = ZX_UART011_ICR,
+        [REG_DMACR]             = ZX_UART011_DMACR,
+};
+
+static struct vendor_data vendor_zte = {
+        .ifls                   = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
+        .fr_busy                = ZX_UART01x_FR_BUSY,
+        .fr_dsr                 = ZX_UART01x_FR_DSR,
+        .fr_cts                 = ZX_UART01x_FR_CTS,
+        .fr_ri                  = ZX_UART011_FR_RI,
+        .lcrh_tx                = REG_LCRH,
+        .lcrh_rx                = REG_ST_LCRH_RX,
+        .reg_lut                = zte_reg,
+        .oversampling           = false,
+        .dma_threshold          = false,
+        .cts_event_workaround   = false,
+        .fixed_options          = false,
+};
+#endif
 
 /* Deals with DMA transactions */
 
@@ -233,6 +289,10 @@ struct uart_amba_port {
         unsigned int            im;             /* interrupt mask */
         unsigned int            old_status;
         unsigned int            fifosize;       /* vendor-specific */
+        unsigned int            fr_busy;        /* vendor-specific */
+        unsigned int            fr_dsr;         /* vendor-specific */
+        unsigned int            fr_cts;         /* vendor-specific */
+        unsigned int            fr_ri;          /* vendor-specific */
         unsigned int            lcrh_tx;        /* vendor-specific */
         unsigned int            lcrh_rx;        /* vendor-specific */
         unsigned int            old_cr;         /* state during shutdown */
@@ -1163,7 +1223,7 @@ static void pl011_dma_shutdown(struct uart_amba_port *uap)
                 return;
 
         /* Disable RX and TX DMA */
-        while (pl011_readw(uap, REG_FR) & UART01x_FR_BUSY)
+        while (pl011_readw(uap, REG_FR) & uap->fr_busy)
                 barrier();
 
         spin_lock_irq(&uap->port.lock);
@@ -1412,11 +1472,11 @@ static void pl011_modem_status(struct uart_amba_port *uap)
         if (delta & UART01x_FR_DCD)
                 uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
 
-        if (delta & UART01x_FR_DSR)
+        if (delta & uap->fr_dsr)
                 uap->port.icount.dsr++;
 
-        if (delta & UART01x_FR_CTS)
-                uart_handle_cts_change(&uap->port, status & UART01x_FR_CTS);
+        if (delta & uap->fr_cts)
+                uart_handle_cts_change(&uap->port, status & uap->fr_cts);
 
         wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
 }
@@ -1487,7 +1547,7 @@ static unsigned int pl011_tx_empty(struct uart_port *port)
         struct uart_amba_port *uap =
             container_of(port, struct uart_amba_port, port);
         unsigned int status = pl011_readw(uap, REG_FR);
-        return status & (UART01x_FR_BUSY|UART01x_FR_TXFF) ? 0 : TIOCSER_TEMT;
+        return status & (uap->fr_busy|UART01x_FR_TXFF) ? 0 : TIOCSER_TEMT;
 }
 
 static unsigned int pl011_get_mctrl(struct uart_port *port)
@@ -1502,9 +1562,9 @@ static unsigned int pl011_get_mctrl(struct uart_port *port)
                 result |= tiocmbit
 
         TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR);
-        TIOCMBIT(UART01x_FR_DSR, TIOCM_DSR);
-        TIOCMBIT(UART01x_FR_CTS, TIOCM_CTS);
-        TIOCMBIT(UART011_FR_RI, TIOCM_RNG);
+        TIOCMBIT(uap->fr_dsr, TIOCM_DSR);
+        TIOCMBIT(uap->fr_cts, TIOCM_CTS);
+        TIOCMBIT(uap->fr_ri, TIOCM_RNG);
 #undef TIOCMBIT
         return result;
 }
@@ -1720,8 +1780,7 @@ static int pl011_startup(struct uart_port *port)
         /*
          * initialise the old status of the modem signals
          */
-        uap->old_status = pl011_readw(uap, REG_FR) &
-                        UART01x_FR_MODEM_ANY;
+        uap->old_status = pl011_readw(uap, REG_FR) & UART01x_FR_MODEM_ANY;
 
         /* Startup DMA */
         pl011_dma_startup(uap);
@@ -1800,7 +1859,7 @@ static void pl011_disable_interrupts(struct uart_amba_port *uap)
         /* mask all interrupts and clear all pending ones */
         uap->im = 0;
         pl011_writew(uap, uap->im, REG_IMSC);
-        pl011_writew(0xffff, REG_ICR);
+        pl011_writew(uap, 0xffff, REG_ICR);
 
         spin_unlock_irq(&uap->port.lock);
 }
@@ -2178,7 +2237,7 @@ pl011_console_write(struct console *co, const char *s, unsigned int count)
          */
         do {
                 status = pl011_readw(uap, REG_FR);
-        } while (status & UART01x_FR_BUSY);
+        } while (status & uap->fr_busy);
         if (!uap->vendor->always_enabled)
                 pl011_writew(uap, old_cr, REG_CR);
 
@@ -2295,7 +2354,7 @@ static void pl011_putc(struct uart_port *port, int c)
         while (pl011_readw(uap, REG_FR) & UART01x_FR_TXFF)
                 ;
         pl011_writeb(uap, c, REG_DR);
-        while (pl011_readw(uap, REG_FR) & UART01x_FR_BUSY)
+        while (pl011_readw(uap, REG_FR) & uap->fr_busy)
                 ;
 }
 
@@ -2441,6 +2500,7 @@ static int pl011_register_port(struct uart_amba_port *uap)
         return ret;
 }
 
+#ifdef CONFIG_ARM_AMBA
 static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
 {
         struct uart_amba_port *uap;
@@ -2464,6 +2524,10 @@ static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
         uap->reg_lut = vendor->reg_lut;
         uap->lcrh_rx = vendor->lcrh_rx;
         uap->lcrh_tx = vendor->lcrh_tx;
+        uap->fr_busy = vendor->fr_busy;
+        uap->fr_dsr = vendor->fr_dsr;
+        uap->fr_cts = vendor->fr_cts;
+        uap->fr_ri = vendor->fr_ri;
         uap->fifosize = vendor->get_fifosize(dev);
         uap->port.irq = dev->irq[0];
         uap->port.ops = &amba_pl011_pops;
@@ -2487,6 +2551,67 @@ static int pl011_remove(struct amba_device *dev)
         pl011_unregister_port(uap);
         return 0;
 }
+#endif
+
+#ifdef CONFIG_SOC_ZX296702
+static int zx_uart_probe(struct platform_device *pdev)
+{
+        struct uart_amba_port *uap;
+        struct vendor_data *vendor = &vendor_zte;
+        struct resource *res;
+        int portnr, ret;
+
+        portnr = pl011_find_free_port();
+        if (portnr < 0)
+                return portnr;
+
+        uap = devm_kzalloc(&pdev->dev, sizeof(struct uart_amba_port),
+                        GFP_KERNEL);
+        if (!uap) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        uap->clk = devm_clk_get(&pdev->dev, NULL);
+        if (IS_ERR(uap->clk)) {
+                ret = PTR_ERR(uap->clk);
+                goto out;
+        }
+
+        uap->vendor     = vendor;
+        uap->reg_lut    = vendor->reg_lut;
+        uap->lcrh_rx    = vendor->lcrh_rx;
+        uap->lcrh_tx    = vendor->lcrh_tx;
+        uap->fr_busy    = vendor->fr_busy;
+        uap->fr_dsr     = vendor->fr_dsr;
+        uap->fr_cts     = vendor->fr_cts;
+        uap->fr_ri      = vendor->fr_ri;
+        uap->fifosize   = 16;
+        uap->port.irq   = platform_get_irq(pdev, 0);
+        uap->port.ops   = &amba_pl011_pops;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+        ret = pl011_setup_port(&pdev->dev, uap, res, portnr);
+        if (ret)
+                return ret;
+
+        platform_set_drvdata(pdev, uap);
+
+        return pl011_register_port(uap);
+out:
+        return ret;
+}
+
+static int zx_uart_remove(struct platform_device *pdev)
+{
+        struct uart_amba_port *uap = platform_get_drvdata(pdev);
+
+        uart_remove_one_port(&amba_reg, &uap->port);
+        pl011_unregister_port(uap);
+        return 0;
+}
+#endif
 
 #ifdef CONFIG_PM_SLEEP
 static int pl011_suspend(struct device *dev)
@@ -2544,6 +2669,10 @@ static int sbsa_uart_probe(struct platform_device *pdev)
 
         uap->vendor     = &vendor_sbsa;
         uap->reg_lut    = vendor_sbsa.reg_lut;
+        uap->fr_busy    = vendor_sbsa.fr_busy;
+        uap->fr_dsr     = vendor_sbsa.fr_dsr;
+        uap->fr_cts     = vendor_sbsa.fr_cts;
+        uap->fr_ri      = vendor_sbsa.fr_ri;
         uap->fifosize   = 32;
         uap->port.irq   = platform_get_irq(pdev, 0);
         uap->port.ops   = &sbsa_uart_pops;
@@ -2593,6 +2722,7 @@ static struct platform_driver arm_sbsa_uart_platform_driver = {
         },
 };
 
+#ifdef CONFIG_ARM_AMBA
 static struct amba_id pl011_ids[] = {
         {
                 .id     = 0x00041011,
@@ -2618,20 +2748,57 @@ static struct amba_driver pl011_driver = {
         .probe          = pl011_probe,
         .remove         = pl011_remove,
 };
+#endif
+
+#ifdef CONFIG_SOC_ZX296702
+static const struct of_device_id zx_uart_dt_ids[] = {
+        { .compatible = "zte,zx296702-uart", },
+        { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, zx_uart_dt_ids);
+
+static struct platform_driver zx_uart_driver = {
+        .driver = {
+                .name   = "zx-uart",
+                .owner  = THIS_MODULE,
+                .pm     = &pl011_dev_pm_ops,
+                .of_match_table = zx_uart_dt_ids,
+        },
+        .probe          = zx_uart_probe,
+        .remove         = zx_uart_remove,
+};
+#endif
+
 
 static int __init pl011_init(void)
 {
+        int ret;
         printk(KERN_INFO "Serial: AMBA PL011 UART driver\n");
 
         if (platform_driver_register(&arm_sbsa_uart_platform_driver))
                 pr_warn("could not register SBSA UART platform driver\n");
-        return amba_driver_register(&pl011_driver);
+
+#ifdef CONFIG_SOC_ZX296702
+        ret = platform_driver_register(&zx_uart_driver);
+        if (ret)
+                pr_warn("could not register ZX UART platform driver\n");
+#endif
+
+#ifdef CONFIG_ARM_AMBA
+        ret = amba_driver_register(&pl011_driver);
+#endif
+        return ret;
 }
 
 static void __exit pl011_exit(void)
 {
         platform_driver_unregister(&arm_sbsa_uart_platform_driver);
+#ifdef CONFIG_SOC_ZX296702
+        platform_driver_unregister(&zx_uart_driver);
+#endif
+#ifdef CONFIG_ARM_AMBA
         amba_driver_unregister(&pl011_driver);
+#endif
 }
 
 /*
diff --git a/include/linux/amba/serial.h b/include/linux/amba/serial.h
index 0ddb5c02ad8b..6a0a89ed7f81 100644
--- a/include/linux/amba/serial.h
+++ b/include/linux/amba/serial.h
@@ -33,12 +33,14 @@
 #define UART01x_DR              0x00    /* Data read or written from the interface. */
 #define UART01x_RSR             0x04    /* Receive status register (Read). */
 #define UART01x_ECR             0x04    /* Error clear register (Write). */
+#define ZX_UART01x_DR           0x04    /* Data read or written from the interface. */
 #define UART010_LCRH            0x08    /* Line control register, high byte. */
 #define ST_UART011_DMAWM        0x08    /* DMA watermark configure register. */
 #define UART010_LCRM            0x0C    /* Line control register, middle byte. */
 #define ST_UART011_TIMEOUT      0x0C    /* Timeout period register. */
 #define UART010_LCRL            0x10    /* Line control register, low byte. */
 #define UART010_CR              0x14    /* Control register. */
+#define ZX_UART01x_FR           0x14    /* Flag register (Read only). */
 #define UART01x_FR              0x18    /* Flag register (Read only). */
 #define UART010_IIR             0x1C    /* Interrupt identification register (Read). */
 #define UART010_ICR             0x1C    /* Interrupt clear register (Write). */
@@ -49,13 +51,21 @@
 #define UART011_LCRH            0x2c    /* Line control register. */
 #define ST_UART011_LCRH_TX      0x2c    /* Tx Line control register. */
 #define UART011_CR              0x30    /* Control register. */
+#define ZX_UART011_LCRH_TX      0x30    /* Tx Line control register. */
 #define UART011_IFLS            0x34    /* Interrupt fifo level select. */
+#define ZX_UART011_CR           0x34    /* Control register. */
+#define ZX_UART011_IFLS         0x38    /* Interrupt fifo level select. */
 #define UART011_IMSC            0x38    /* Interrupt mask. */
 #define UART011_RIS             0x3c    /* Raw interrupt status. */
 #define UART011_MIS             0x40    /* Masked interrupt status. */
+#define ZX_UART011_IMSC         0x40    /* Interrupt mask. */
 #define UART011_ICR             0x44    /* Interrupt clear register. */
+#define ZX_UART011_RIS          0x44    /* Raw interrupt status. */
 #define UART011_DMACR           0x48    /* DMA control register. */
+#define ZX_UART011_MIS          0x48    /* Masked interrupt status. */
+#define ZX_UART011_ICR          0x4c    /* Interrupt clear register. */
 #define ST_UART011_XFCR         0x50    /* XON/XOFF control register. */
+#define ZX_UART011_DMACR        0x50    /* DMA control register. */
 #define ST_UART011_XON1         0x54    /* XON1 register. */
 #define ST_UART011_XON2         0x58    /* XON2 register. */
 #define ST_UART011_XOFF1        0x5C    /* XON1 register. */
@@ -75,15 +85,19 @@
 #define UART01x_RSR_PE          0x02
 #define UART01x_RSR_FE          0x01
 
+#define ZX_UART01x_FR_BUSY      0x300
 #define UART011_FR_RI           0x100
 #define UART011_FR_TXFE         0x080
 #define UART011_FR_RXFF         0x040
 #define UART01x_FR_TXFF         0x020
 #define UART01x_FR_RXFE         0x010
 #define UART01x_FR_BUSY         0x008
+#define ZX_UART01x_FR_DSR       0x008
 #define UART01x_FR_DCD          0x004
 #define UART01x_FR_DSR          0x002
+#define ZX_UART01x_FR_CTS       0x002
 #define UART01x_FR_CTS          0x001
+#define ZX_UART011_FR_RI        0x001
 #define UART01x_FR_TMSK         (UART01x_FR_TXFF + UART01x_FR_BUSY)
 
 #define UART011_CR_CTSEN        0x8000  /* CTS hardware flow control */