#include <vhex/driver/mpu/sh/sh7305/keysc.h>
#include <vhex/driver/mpu/sh/sh7305/intc.h>
#include <vhex/driver.h>

/* define the private KeyScan context structure */
struct keysc_ctx {
	struct __sh7305_keysc_s keysc;
	uint16_t iprf;
};

/* hardware configuration call */

/* __keysc_configure() : configure the SH7305_KEYSC module */
static void __keysc_configure(struct keysc_ctx *ctx)
{
	/* configure the scan control
	   <> enable the SH7305_KEYSC interruption (0xbe0)
	   <> set undocumented bit _O to 0 (Casio's configuration)
	   <> set undocumented bit _1 to 0 (Casio's configuration) */
	ctx->keysc.KIUCNTREG.KEYIE = 1;
	ctx->keysc.KIUCNTREG._0 = 0;
	ctx->keysc.KIUCNTREG._1 = 0;

	/* configure the key-bounce fix setting
	   <> enable the key-bounce "fix"
	   <> set the undocumented bit _0 to 0b100 (Casio's configuration)
	   <> set the undocumented bit _1 to 0b010 (Casio's configuration) */
	ctx->keysc.KIAUTOFIXREG.KEYBE = 1;
	ctx->keysc.KIAUTOFIXREG._0 = 0b100;
	ctx->keysc.KIAUTOFIXREG._1 = 0b010;

	/* configure the scan mode
	   <> set undocumented bit _O to 0 (Casio's configuration)
	   <> set undocumented bit _1 to 0 (Casio's configuration)
	   <> set undocumented bit _2 to 1 (Casio's configuration) */
	ctx->keysc.KIUMODEREG._0 = 0;
	ctx->keysc.KIUMODEREG._1 = 0;
	ctx->keysc.KIUMODEREG._2 = 1;

	/* configure the interrupt setting
	   This part is wierd because I cannot explain why this configurates
	   generate the whanted behaviour (generate interrupt when a falling
	   or a pressed or a rising edge is detected on any keys).

	   This configuration has been discovered by practicing a lot a blind
	   test with the hardware. */
	ctx->keysc.KIUINTREG.KYCPU_IE = 0b0000010;

	/* configure the time between each interrupt
	   <> remove time between interruption (Casio's configuration) */
	ctx->keysc.KIUWSETREG.TIME = 0x05;

	/* configure the interval value between each scan
	   <> use the Casio's configuration */
	ctx->keysc.KIUINTERVALREG = 0x0098;

	/* configure the key output ???? */
	ctx->keysc.KYOUTDR.KYO5DT = 0b11;
	ctx->keysc.KYOUTDR.KYO4DT = 0b11;
	ctx->keysc.KYOUTDR.KYO3DT = 0b11;
	ctx->keysc.KYOUTDR.KYO2DT = 0b11;
	ctx->keysc.KYOUTDR.KYO1DT = 0b11;
	ctx->keysc.KYOUTDR.KYO0DT = 0b11;

	/* configure the key input setting
	   <> enable F1, SHIFT, ALPHA, xoT, div, 7, 4, 1, 0
	   <> enable F2, OPT, sqrt, log, FD, 8, 5, 2, .
	   <> enable F3, var, ^, ln, (, 9, 6, 3, expo
	   <> enable F4, menu, exit, sin, ), del, x, +, (-)
	   <> enable F5, <, down, cos, [,], %, -, EXE
	   <> enable F6, up, >, tan, ->
	   <> enable AC/ON */
	ctx->keysc.KYINDR.KYDIR6 = 1;
	ctx->keysc.KYINDR.KYDIR5 = 1;
	ctx->keysc.KYINDR.KYDIR4 = 1;
	ctx->keysc.KYINDR.KYDIR3 = 1;
	ctx->keysc.KYINDR.KYDIR2 = 1;
	ctx->keysc.KYINDR.KYDIR1 = 1;
	ctx->keysc.KYINDR.KYDIR0 = 1;

	/* set the interrupt level (max) */
	ctx->iprf = 0b1111;

	/* intall the KEYSC interupt handler */
	extern void sh7305_keysc_inth(void);
	sh7305_intc_install_inth(0xbe0, &sh7305_keysc_inth, 64);
}

/* __keysc_hsave() : save hardware information */
static void __keysc_hsave(struct keysc_ctx *ctx)
{
	ctx->keysc.KIUCNTREG.word    = SH7305_KEYSC.KIUCNTREG.word;
	ctx->keysc.KIAUTOFIXREG.word = SH7305_KEYSC.KIAUTOFIXREG.word;
	ctx->keysc.KIUMODEREG.word   = SH7305_KEYSC.KIUMODEREG.word;
	ctx->keysc.KIUINTREG.word    = SH7305_KEYSC.KIUINTREG.word;
	ctx->keysc.KIUWSETREG.word   = SH7305_KEYSC.KIUWSETREG.word;
	ctx->keysc.KIUINTERVALREG    = SH7305_KEYSC.KIUINTERVALREG;
	ctx->keysc.KYOUTDR.word      = SH7305_KEYSC.KYOUTDR.word;
	ctx->keysc.KYINDR.word       = SH7305_KEYSC.KYINDR.word;
	ctx->iprf = SH7305_INTC._IPRX->IPRF.KEYSC;
}

/* __keysc_hrestore() : restore hadware information */
static void __keysc_hrestore(struct keysc_ctx *ctx)
{
	/* force mask the SH7305_KEYSC module, otherwise the module will crash */
	SH7305_INTC._MSK->IMR5.KEYSC = 1;
	SH7305_INTC._IPRX->IPRF.KEYSC = 0b0000;

	/* restore registers */
	SH7305_KEYSC.KIUCNTREG.word    = ctx->keysc.KIUCNTREG.word;
	SH7305_KEYSC.KIAUTOFIXREG.word = ctx->keysc.KIAUTOFIXREG.word;
	SH7305_KEYSC.KIUMODEREG.word   = ctx->keysc.KIUMODEREG.word;
	SH7305_KEYSC.KIUINTREG.word    = ctx->keysc.KIUINTREG.word;
	SH7305_KEYSC.KIUWSETREG.word   = ctx->keysc.KIUWSETREG.word;
	SH7305_KEYSC.KIUINTERVALREG    = ctx->keysc.KIUINTERVALREG;
	SH7305_KEYSC.KYOUTDR.word      = ctx->keysc.KYOUTDR.word;
	SH7305_KEYSC.KYINDR.word       = ctx->keysc.KYINDR.word;

	/* enable keysc interuption */
	SH7305_INTC._IPRX->IPRF.KEYSC = ctx->iprf;
	SH7305_INTC._MSKCLR->IMR5.KEYSC = 1;
}

/* declare the KEYSC driver */

struct vhex_driver drv_keysc = {
	.name       = "KEYSC",
	.hsave      = (void*)&__keysc_hsave,
	.hrestore   = (void*)&__keysc_hrestore,
	.configure  = (void*)&__keysc_configure,
	.state_size = sizeof(struct keysc_ctx)
};
VHEX_DECLARE_DRIVER(03, drv_keysc);